Prepared in cooperation with the

U.S. Environmental Protection Agency EPA

Geomorphic Responses to Stream Channel Restoration 

at Minebank Run, Baltimore County, Maryland, 2002–08

Scientific Investigations Report 2012–5012

U.S. Department of the Interior

U.S. Geological Survey
Cover.  View looking upstream at restored section of Minebank Run in Cromwell Valley Park, Baltimore County, Maryland, with original 

stream channel visible in the background, 2005. (Photograph by Kenneth Jewell, U.S. Environmental Protection Agency.)
Geomorphic Responses to Stream Channel 

Restoration at Minebank Run, Baltimore 

County, Maryland, 2002–08

By Edward J. Doheny1, Jonathan J.A. Dillow1, Paul M. Mayer2, and Elise A. Striz3

1

 U.S. Geological Survey, Baltimore, Maryland

2

 U.S. Environmental Protection Agency, Office of Research and Development, Ada, Oklahoma

3

 Formerly of U.S. Environmental Protection Agency, Office of Research and Development, Ada, Oklahoma

Scientific Investigations Report 2012–5012

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the

U.S. Environmental Protection Agency
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2012

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reproduce any copyrighted materials contained within this report.

Suggested citation:

Doheny, E.J., Dillow, J.J.A., Mayer, P.M., and Striz, E.A., 2012, Geomorphic responses to stream channel restoration 

at Minebank Run, Baltimore County, Maryland, 2002–08: U.S. Geological Survey Scientific Investigations Report 

2012–5012, 61 p.

ISBN 978-1-4113-3360-4
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................2

Purpose and Scope ..............................................................................................................................2

Description of Study Area ...................................................................................................................3

Methods of Data Collection .........................................................................................................................5

Streamflow.............................................................................................................................................9

Precipitation...........................................................................................................................................9

Longitudinal Profiles.............................................................................................................................9

Cross Sections.....................................................................................................................................10

Pebble Counts......................................................................................................................................12

Bed-Elevation Measurements..........................................................................................................12

High-Water Marks ..............................................................................................................................13

Watershed Hydrology .................................................................................................................................13

Precipitation.........................................................................................................................................14

Discharge Intensity.............................................................................................................................14

Time of Concentration........................................................................................................................14

Flood Frequency .................................................................................................................................18

Rainfall-Runoff Relations...................................................................................................................18

Comparison of Pre- and Post-Restoration Geomorphic Characteristics ..........................................19

Longitudinal Profiles...........................................................................................................................19

Cross-Section Geometry ...................................................................................................................24

Hydraulic-Geometry Relations .........................................................................................................30

Grain-Size Distribution.......................................................................................................................32

Net Changes in Channel Bed Elevation ..........................................................................................37

Cross Section Ee........................................................................................................................37

Cross Section Ff .........................................................................................................................40

Cross Section Gg .......................................................................................................................40

Study Reach Summary..............................................................................................................40

Shear Stress Analysis........................................................................................................................41

Net Changes in Sediment Volume....................................................................................................41

Comparison of 1960s Bed Elevations and Longitudinal Profile to 2002–08 

Study Reach Conditions ................................................................................................................43

Data Limitations............................................................................................................................................44

Summary and Conclusions.........................................................................................................................46

Acknowledgments.......................................................................................................................................47

References Cited..........................................................................................................................................48

Glossary.........................................................................................................................................................51

Appendix 1. Changes in Cross-Section Geometry at Permanent Cross Sections

in the Minebank Run Study Reach, 2005 through 2008 ............................................................53
iv

Figures

1. Map showing location of Minebank Run watershed and study area, 

Baltimore County, Maryland .......................................................................................................4

2. Photograph showing view looking downstream at section of Minebank 

Run that was restored in 1998–99, upstream of the Baltimore Beltway 

(I-695), 2003 ....................................................................................................................................5

3. Map showing detailed view of Minebank Run watershed and study reach, 

Baltimore County, Maryland .......................................................................................................6

4–5. Photographs showing—

4. View looking upstream at unrestored section of Minebank Run in 

Cromwell Valley Park downstream of the Baltimore Beltway (I-695), 

2003 ........................................................................................................................................7

5. View looking upstream at restored section of Minebank Run in 

Cromwell Valley Park with original stream channel visible in the 

background, 2005.................................................................................................................7

6–7. Maps showing—

6. Location of continuous-record streamgage, crest-stage partial-record 

stations, precipitation gage, and well transects along the Minebank 

Run study reach, Baltimore County, Maryland...............................................................8

7. Locations of permanent cross sections that were established and 

surveyed in the Minebank Run study reach at Cromwell Valley Park, 

2002–08 ................................................................................................................................11

8–9. Graphs showing—

8. Plot of grain-size distribution developed from the pebble count at 

cross section Ff, Minebank Run study reach, May 9, 2005.........................................14

9. Relations between instantaneous peak discharge and ratios of 

daily-mean and event-mean discharges, pre- and post-restoration, 

at station 0158397967, Minebank Run near Glen Arm, Maryland ..............................15

10. Map showing locations and contributing areas of watersheds draining 

to station 01585200, West Branch Herring Run at Idlewylde, Maryland 

and station 0158397967, Minebank Run near Glen Arm, Maryland....................................17

11–12. Graphs showing—

11. Maximum rainfall intensity against time of concentration for 

Minebank Run and West Branch Herring Run for selected pre- and 

post-restoration storm events, water years 2002 through 2008.................................17

12. Linear relation between log-transformed annual peak discharges at 

Minebank Run and coincident peaks at West Branch Herring Run .........................18

13. Aerial photograph showing Minebank Run study reach in Cromwell Valley 

Park prior to channel restoration.............................................................................................21

14–15. Graphs showing—

14. Longitudinal profile of channel features in the Minebank Run study 

reach from field survey conducted on March 30, 2005 ...............................................21

15. Comparison of riffle, pool, and run distribution and percentages in 

the Minebank Run study reach before and after channel restoration, 

2002 through 2008 ..............................................................................................................23

16–24. Graphs showing post-restoration cross-section geometry at—

16. Permanent cross section Aa, April 2005 through April 2008 ......................................25

17. Permanent cross section Bb, April 2005 through April 2008 ......................................25
v

18. Permanent cross section Cc, April 2005 through April 2008 ......................................25

19. Permanent cross section Dd, April 2005 through April 2008 ......................................26

20. Permanent cross section Ee, April 2005 through April 2008.......................................26

21. Permanent cross section Ff, April 2005 through April 2008........................................26

22. Permanent cross section Gg, April 2005 through April 2008 ......................................27

23. Permanent cross section Hh, April 2005 through April 2008 ......................................27

24. Permanent cross section Ii, April 2005 through April 2008.........................................27

25. Map showing summary of post-restoration geomorphic conditions in the 

Minebank Run study reach, 2005 through 2008 .....................................................................31

26–27. Graphs showing—

26. Comparison of pre- and post-restoration hydraulic-geometry relations of 

cross-sectional area, channel width, mean channel depth, and mean 

velocity against discharge using discharge measurements of less than 

10 cubic feet per second at U.S. Geological Survey station 0158397967, 

Minebank Run near Glen Arm, Maryland ...............................................................................33

27. Comparison of composite pebble counts for Minebank Run study reach 

above Sherwood Bridge before and after channel restoration, 2003 

through 2008 ................................................................................................................................38

28–30. Graphs showing comparison of particle-size distributions at—

28. Cross section Ee, 2002 through 2008 ..............................................................................38

29. Cross section Ff, 2002 through 2008................................................................................38

30. Cross section Gg, 2002 through 2008..............................................................................38

31–33. Graphs showing net changes in bed elevation over time at—

31. Cross section Ee, January 2, 2003 through October 7, 2008.......................................39

32. Cross section Ff, December 3, 2002 through October 7, 2008 ....................................39

33. Cross section Gg, January 2, 2003 through September 15, 2008 ...............................39

34–36. Graphs showing—

34. Boundary shear stress versus mean velocity at the peak discharge 

during storm events in the Minebank Run study reach, November 

2001 through September 2004, and December 2004 through August 

2008 ......................................................................................................................................42

35. Generalized pre-restoration channel bed profile upstream of 

Sherwood Bridge, Minebank Run study reach, early 1960s and 2002......................45

36. Generalized post-restoration channel bed profile upstream of 

Sherwood Bridge, Minebank Run study reach, 2005 and 2008..................................45

Tables

1. Summary of streamflow statistics for U.S. Geological Survey station 

0158397967, Minebank Run near Glen Arm, Maryland, water years 2002–08 ....................9

2. Total precipitation recorded in vicinity of the Minebank Run study reach 

during water years 2002 through 2008 ......................................................................................9

3. Dates, locations, and longitudinal stationing used for the longitudinal-profile 

surveys in the Minebank Run study reach, 2002–08.............................................................10

4. Basic station information for permanent cross sections located in the 

Minebank Run study reach after restoration, 2005–08.........................................................12
vi

5. Grain-size distribution and computation of percent finer from pebble 

count at cross section Ff, Minebank Run study reach, May 9, 2005..................................13

6. Time of concentration for 38 selected storms in the Minebank Run and 

West Branch Herring Run watersheds, water years 2002 through 2008 ..........................16

7. Comparison of flood-frequency analyses for Minebank Run, based on 

station data from 1997–2004 and normalized from long-term estimates at 

West Branch Herring Run .........................................................................................................19

8. Runoff amounts and percentages for 41 selected storm events at 

U.S. Geological Survey station 0158397967, Minebank Run near Glen Arm, 

Maryland, water years 2002 through 2008..............................................................................20

9. Slopes of the channel bed and water surface in the Minebank Run study 

reach from longitudinal profile surveys, 2002–08..................................................................22

10. Percentages of riffles, pools, and runs in the Minebank Run study reach 

from longitudinal-profile surveys, 2002–08.............................................................................22

11. Changes in cross-section geometry at permanent cross-section Hh, 

Minebank Run study reach, 2005 through 2008 .....................................................................28

12. Summary of variability of cross-sectional characteristics in the Minebank 

Run study reach, 2005 through 2008 ........................................................................................29

13. Cumulative distribution of grain sizes, in percent finer, for surficial bed 

material at permanent cross section locations in the Minebank Run study 

reach, May 2005..........................................................................................................................34

14. Cumulative distribution of grain sizes, in percent finer, for surficial bed 

material at permanent cross section locations in the Minebank Run study 

reach, October 2006 ...................................................................................................................34

15. Cumulative distribution of grain sizes, in percent finer, for surficial bed 

material at permanent cross section locations in the Minebank Run study 

reach, April 2008 .........................................................................................................................35

16. Median particle diameter from pebble counts associated with each 

permanent cross section in the Minebank Run study reach, 2002 through 

2008 ...............................................................................................................................................36

17. Grain-size distributions and computation of percent finer from composite 

pebble counts at all permanent cross sections, Minebank Run study reach, 

2003 through 2008 .......................................................................................................................36

18. Data variables and boundary shear stress computations for 11 storm 

runoff events in the Minebank Run study reach, December 2004 through 

August 2008..................................................................................................................................42

19. Changes in volume, in cubic feet, between cross-sectional surveys for 

reach segments associated with each permanent cross section, Minebank 

Run study reach, December 2002 through April 2008...........................................................43

20. Estimates of sediment volume and rate of change in sediment volume 

stored or removed from the Minebank Run study reach, December 2002 

through April 2008.......................................................................................................................43

21. Thalweg elevations at cross section Hh from longitudinal profile surveys 

between 2002 and 2008, and corresponding differences from early 1960s 

channel bed elevation................................................................................................................45
vii

Conversion Factors and Vertical Datums

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 4,047 square meter (m2

)

acre 0.004047 square kilometer (km2

)

square mile (mi2

) 259 hectare (ha)

square mile (mi2

) 2.59 square kilometer (km2)

Volume

cubic foot (ft3

) 0.000023 acre-feet (acre-ft)

Flow rate

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

inch per hour (in/hr) 25.4 millimeter per hour (mm/hr)

Mass

pound, avoirdupois (lb) 0.4536 kilogram (kg) 

ton, short (2,000 lb) 907.2 kilogram (kg)

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

 °C = (°F - 32) / 1.8

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29). 

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

Abbreviations

CIES Cary Institute of Ecosystem Studies

d50 Median particle diameter

I-695 Interstate 695, Baltimore Beltway

NAD 83 North American Datum of 1983

NGVD 29 National Geodetic Vetical Datum of 1929

R2 Coefficient of determination

USEPA U.S. Environmental Protection Agency 

USGS U.S. Geological Survey

Geomorphic Responses to Stream Channel Restoration at 

Minebank Run, Baltimore County, Maryland, 2002–08

By Edward J. Doheny, Jonathan J.A. Dillow, Paul M. Mayer, and Elise A. Striz

Abstract

Data collected from 2002 through 2008 by the 

U.S. Geological Survey, in cooperation with the U.S. 

Environmental Protection Agency, were used to assess geomorphic characteristics and geomorphic changes over time 

in a reach of Minebank Run, a small urban watershed near 

Towson, Maryland, prior to and after its physical restoration 

in 2004 and 2005. Data collection included continuous-record 

streamflow and precipitation; surveyed elevations of the 

channel bed, water surface, and bank features; surveyed cross 

sections; pebble counts from the channel bed; measurements 

of bed elevation over time; and high-water marks from storm 

runoff events.

To provide hydrologic context to the geomorphic 

monitoring that was conducted during the study period, 

precipitation, discharge intensity, time of concentration, flood 

frequency, and rainfall-runoff relations were investigated. 

Hydrologic conditions were found to be comparable for the 

pre- and post-restoration monitoring periods. Flood frequency 

analysis indicated that the largest peak flows that occurred in 

the Minebank Run watershed during 2002–08 could represent 

events of lower probability when compared to a longer 

peak-flow record in the adjacent West Branch Herring Run 

watershed.

Longitudinal profiles of the channel bed and water surface indicated differences in the distribution and location of 

riffles, pools, and runs during 2002–08. During both the preand post-restoration monitoring periods, the analyses indicated 

that on average, the stream is maintaining the overall slope of 

the channel bed and water surface at about 1 percent, despite 

considerable changes in the percentages of riffles, pools, and 

runs, and changes in the distribution and location of these 

features. 

Post-restoration, lateral erosion has been reduced with 

fewer indications of channel widening. Flood flows can now 

inundate sections of the overbank area, and also bypass the 

main channel in small sections of the study reach, which was 

not possible before restoration. Much of the post-restoration 

geomorphic variability is due to alternating patterns of sediment storage and removal, and shifting of the channel thalweg, 

in contrast to channel degradation and widening, and lateral 

erosion from receding cut banks observed during the prerestoration monitoring. Reduced variability in cross-sectional 

area and mean depth between surveys conducted from 2006 

through 2008 indicates that the stream channel could be establishing a dynamic equilibrium and a more stable geometry 

after the initial geomorphic response observed in 2005 and 

2006, just after restoration in 2004 and 2005.

Most channel geometry variables had moderate to strong 

linear relations with discharge. Pre-restoration, the strongest 

relation was between cross-sectional area and discharge. 

Post-restoration, the strongest relation was between mean flow 

velocity and discharge. 

Composite particle-size analyses of the channel bed from 

pebble counts over time indicated that sources of fine sediment, possibly from bank erosion, still exist in the watershed 

despite restoration of the stream channel. The abundance of 

relatively small bed material sizes in combination with flashy 

streamflow from urban and suburban runoff likely contributes 

to the considerable changes in grain-size distribution and alternating periods of storage and transport of sand and gravel.

Sequential measurements of bed elevation over time in 

three selected locations of the study reach indicated a period 

of considerable vertical adjustment between September 2005 

and December 2006 based on post-restoration monitoring. 

One of the three selected locations was in one of the most 

geomorphically unstable sections of the study reach before 

restoration, and was found to be considerably less prone to 

rapid and extreme changes in bed elevation after restoration of 

the stream channel.

An analysis of boundary shear stress was conducted by 

use of measured channel-geometry variables and water-surface 

slopes in the vicinity of the continuous-record streamgage. 

The results indicated that, post-restoration, larger increases in 

mean velocity were required to initiate sediment transport in 

the stream channel.

Pre-restoration, sediment volume computations indicated 

that sediment was being removed from the study reach, with 

the largest sediment volume and rate of removal occurring 

during December 2002 through July 2003. Post-restoration, 

an alternating pattern of sediment removal and storage was 
2 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

observed, with the largest sediment volume and rate of 

removal occurring during April 2005 to December 2005, just 

after completion of the restoration. The largest volumes and 

rates of sediment storage during the post-restoration period 

occurred between December 2005 and September 2006. The 

storm and flood of June 25, 2006 was a likely factor in the volume of sediment stored in the study reach during this period.

Comparing an early 1960s channel bed profile to those 

developed during 2002–08 confirmed that the stream channel 

has maintained an overall slope of about 1 percent for greater 

than 40 years. Comparisons of bed elevations between the 

early 1960s and 2002 indicate that the channel bed degraded 

within an approximate range of 1.3 ft (feet) to 5.0 ft, and 

with possible local scour of up to 5.6 ft near a sanitary sewer 

pipe that was exposed within the channel bed. In the postrestoration condition, the channel bed is still about 0.8 ft to 4.8 

ft lower than bed elevations from the early 1960s at approximately equivalent locations along the profile.

Introduction

Minebank Run, a small urban stream in Baltimore 

County, Maryland, is a tributary to the Gunpowder River in 

the Chesapeake Bay watershed that drains approximately 3.27 

mi2 (square miles) (Doheny and others, 2007). During two 

phases of work occurring between 1999 and 2005, Minebank 

Run was the focus of physical restoration efforts by the 

Baltimore County Department of Environmental Protection 

and Resource Management (Lutz, 2006; Doheny and others, 

2007). One of the primary goals of the physical restoration 

was to re-establish geomorphic stability1 of the stream 

channel.

Urban streams, such as Minebank Run, commonly 

display flashy streamflow due to rapid runoff from impervious 

surfaces. The flashy streamflow can alter the bed and banks of 

the stream channel considerably over time. The erosive power 

that is generated in urban streams often leads to degradation 

and widening of stream channels, bank failure, increased sediment supply, and instability of riffle and pool features along 

the channel profile (Paul and Meyer, 2001). In order to address 

these problems, stream channel restorations are often designed 

to adjust channel sinuosity and pattern, stabilize channel 

dimension, reshape banks and re-introduce riparian vegetation, and stabilize the longitudinal profile of the channel.

In April 2001, the U.S. Environmental Protection Agency 

(USEPA) began investigating opportunities in the Baltimore 

metropolitan area to study streams that were targeted for restoration to improve physical function and habitat. Baltimore 

was a focus area for stream restoration research because of a 

large number of projects that had been carried out since the 

early 1990s. Minebank Run was selected for study because 

of the opportunity to study potential water-quality benefits 

from implementation of specific restoration practices, such 

as re-planting vegetation in riparian zones, reconfiguring of 

meanders and point bars, reconstruction of flood plains, and 

physical movement of sections of the channel within the valley. In October 2001, the U.S. Geological Survey (USGS), the 

USEPA, and the Cary Institute of Ecosystem Studies (CIES) 

jointly initiated a study to investigate the effects of stream restoration on stream hydrology, denitrification, and overall water 

quality in a selected reach of Minebank Run (Groffman and 

others, 2005; Doheny and others, 2006; Striz and Mayer, 2008; 

Kaushal and others, 2008; Mayer and others, 2010; Harrison 

and others, 2011). Instrumentation, including a continuousrecord streamgage and precipitation gage, was installed 

by USGS to document the stream hydrology. In response to 

rapid changes in channel geometry and elevations of channel 

features, as well as the rate of lateral migration of the stream 

channel observed during the first year of the study, the USGS 

was also tasked with measuring and documenting the geomorphic changes within the Minebank Run study reach before and 

after physical restoration (Doheny and others, 2007).

Purpose and Scope

Data collected from water years 2002 through 2008 were 

used to assess and compare pre-and post-restoration geomorphic characteristics and changes in these characteristics 

over time in the Minebank Run study reach. Pre-restoration 

geomorphic monitoring in the study reach occurred between 

November 2001 and August 2004. Channel restoration construction occurred in the watershed between June 2004 and 

February 2005, with the majority of the physical construction 

in the study reach occurring between October and December 

2004. Post-restoration geomorphic monitoring occurred 

between December 2004 and September 2008. For purposes 

of hydrologic evaluation, October 2004 is considered to be 

the break between the pre- and post-restoration monitoring 

periods. 

The report describes conventional techniques that were 

used for geomorphic data collection and comparative analysis 

of the data. The report also includes a brief overview of 

watershed hydrology and flood frequency during the period 

of investigation. Analyses conducted for this report include 

pre- and post-restoration comparisons of (1) longitudinal 

profiles of the channel bed and water surface; (2) changes in 

cross-section geometry due to aggradation, degradation, and 

lateral erosion; (3) hydraulic-geometry relations of the stream 

channel; (4) grain-size distribution of the channel bed; (5) net 

changes in bed elevation at selected locations over time; (6) 

boundary shear stress based on cross-section geometry and 

water-surface slope in the vicinity of the continuous-record 

streamgage; and (7) estimates of net change in sediment 

volume stored or removed from the study reach between 

cross-sectional surveys. The report also presents a comparison 

of bed elevations and a longitudinal profile from the 1960s to 

study reach conditions found between water years 2002 and 

2008. 1

 Words in bold are defined in the glossary section at the end of the report.
Introduction 3

Description of Study Area

Minebank Run is a 3.27-mi2 sub-watershed of the 

Gunpowder Falls located in the south-central section of 

Baltimore County, Maryland, approximately 4.7 mi (miles) 

northwest of the Fall Line in the Piedmont Physiographic 

Province (fig. 1). The watershed lies between 39° 23′ 34′′ and 

39° 25′ 26′′ north latitude, and between 76° 32′ 07′′ and 76° 

35′ 40′′ west longitude. The headwaters are located on the 

east side of Towson, Maryland. The stream flows roughly in a 

northeasterly direction and confluences with Gunpowder Falls 

near the town of Loch Raven, approximately 0.30 mi downstream of the lower dam on Loch Raven Reservoir (Doheny 

and others, 2006; Doheny and others, 2007). 

The Minebank Run watershed is bounded by 2 ridges 

that are oriented approximately from southwest to northeast, 

with a broad, lightly sloping valley in between. The ridges are 

comprised of metamorphic rocks, namely schists and quartzites. The valley is underlain by marble that is mostly covered 

by colluvium and alluvium, with the exception of some parts 

of the stream channel where the marble is exposed. The valley 

width ranges from approximately 0.6 mi near the headwater 

and outlet areas, to about 1.5 mi near the mid-point of the 

watershed. The watershed ranges in elevation from about 400 

to 500 ft (feet) above the National Geodetic Vertical Datum 

of 1929 (NGVD 29) at the drainage boundaries, to about 150 

to 400 ft above NGVD 29 in the stream valley. Relief ranges 

from 100 to 300 ft in most areas of the watershed (Doheny and 

others, 2006; Doheny and others, 2007).

As of 2004, the Minebank Run watershed consisted of a 

restored section and an unrestored section. The upper 0.80 mi2 

of the watershed, which is upstream of the Baltimore Beltway 

(I-695) (fig. 1), was restored in 1998 and 1999. Restoration 

was initiated in the lower 2.47 mi2

 of the watershed during 

June 2004 and was completed in about February 2005 

(Doheny and others, 2006; Doheny and others, 2007).

In the section of the watershed that was restored during 

1998 and 1999, the dimension, pattern, and profile of the 

stream channel were reconstructed for purposes of improving 

stability. Riffle and pool sequences were re-created by selective placement of rock weirs (Rosgen, 1993), which were 

also intended to control sediment supply in the watershed. 

Where possible, flood plains were created to allow flood flows 

to spread out in the valley and reduce the energy directed at 

the channel bed. Channel-bank slopes were reduced in many 

locations and natural vegetation was planted on the banks. 

Riprap was used to harden channel banks in selected locations to protect sewer infrastructure located in the valley. Low 

to moderate channel sinuosity was maintained throughout the 

restored reaches to reduce the potential for lateral bank erosion 

and failure (fig. 2) (Doheny and others, 2007). 

The study reach at Minebank Run drains 2.06 mi2

 (fig. 3) 

and was selected for monitoring of both pre-restoration and 

post-restoration conditions related to the 2004–05 channel restoration. The length of the study reach is approximately 1,800 

ft. At this location, land use in the watershed is approximately 

80.6 percent urban, and 16.9 percent forested or open space 

(Baltimore County Department of Environmental Protection 

and Resource Management, 2000). The largest percentages of 

urban land use and impervious surfaces are in the headwaters 

of the watershed, upstream of I-695. Most of these highly 

impervious areas are at higher elevations near the southern 

section of the drainage boundary. These areas, in combination 

with direct runoff from I-695, are the likely sources of 

increased storm runoff that causes the stream stage and corresponding discharge to increase and decrease very quickly 

during storm events (Doheny and others, 2006; Doheny and 

others, 2007).

Prior to restoration in 2004 and 2005, much of the study 

reach at Minebank Run was entrenched and over-widened 

(Doheny and others, 2006). Most of the stream energy was 

being directed at the channel bed and banks, with little or 

no ability for the streamflow to overtop the channel banks 

and spread out onto the flood plain. The channel banks were 

steeply sloped in many locations with numerous occurrences 

of bank failure and lateral erosion. The channel sinuosity was 

fairly low, but several locations in the study reach had large 

meanders that coincided with very unstable channel banks and 

a highly mobile and unstable channel bed (fig. 4) (Doheny and 

others, 2006; Doheny and others, 2007).

Prior to restoration in 2004 and 2005, the bed material in 

the study reach consisted of a mixture of sand, gravel, cobbles, 

and a few small boulders. In this section of the watershed, 

much of the flood plain and channel bed lie within the deposits 

of alluvium and colluvium mapped by Crowley and Cleaves 

(1974). Few bedrock outcrops were visible in the study reach 

because of the deposits of alluvium and colluvium. Bank 

material included some deposits of sand and gravel, with 

greater percentages of silt and clay than in the channel bed 

(Doheny and others, 2007). 

Restoration techniques similar to those described above 

were used in the lower section of the Minebank Run watershed 

during 2004 and 2005 to restore what had been a degraded 

and over-widened stream channel (Doheny and others, 2006; 

Doheny and others, 2007). The channel bed was reconstructed 

with large gravel and small cobbles that were trucked in from 

outside the watershed. In addition to the restoration techniques 

described above, the stream channel was physically moved 

within the valley in two locations of the study reach that had 

large, highly sinuous meanders. In addition to reducing the 

sinuosity, the original stream channel was left in place as an 

overflow channel in these locations, thus allowing a percentage of stormflows to bypass the newly restored stream channel 

in these locations (fig. 5).

The study reach selected for geomorphic investigation 

also overlapped a study reach where shallow groundwater and 

water quality were monitored between 2001 and 2008 (fig. 6) 

(Mayer and others, 2003; Groffman and others, 2005; Doheny 

and others, 2006; Doheny and others, 2007; Striz and Mayer, 

2008; Kaushal and others, 2008; Mayer and others, 2010; 

Harrison and others, 2011). The study design for groundwater and water-quality monitoring included nests of three 
4 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Figure 1. Location of Minebank Run watershed and study area, Baltimore County, Maryland.
Methods of Data Collection 5

Figure 2. View looking downstream at section of Minebank Run that was restored in 1998–99, upstream 

of the Baltimore Beltway (I-695), 2003. (Photograph by Paul M. Mayer, U.S. Environmental Protection 

Agency.)

1-in. (inch)-diameter piezometers that were installed 2 to 6 

ft below the surface of the channel bed, and 3.75 to 11.85 ft 

below the land surface on the channel banks in three selected 

locations along Minebank Run (fig. 6) (Doheny and others, 

2006). The tops of the piezometers in the channel bed also 

were used in the geomorphic investigation as measuring points 

for tracking channel-bed elevations over time (Doheny and 

others, 2007). 

Methods of Data Collection

Geomorphic data were collected in the Minebank Run 

study reach to quantify pre- and post-restoration streamchannel characteristics, and to assess changes to the stream 

channel prior to and after restoration. Descriptions of methods 

used for data collection during 2002 through 2004 are presented in Doheny and others (2007). Similar techniques were 

used for continued data collection in the study reach between 

2005 and 2008.

A continuous-record streamgage (USGS station number 

0158397967, Minebank Run near Glen Arm, Maryland) (fig. 

6) has provided 5-minute, unit-value stage and discharge 

data in the Minebank Run study reach since October 2001. A 

continuous-record precipitation gage (USGS station number 

392449076331100) (fig. 6) has provided 5-minute, unit value 

precipitation data in the Minebank Run watershed near the 

study reach since October 2001. Pre- and post-restoration 

surveys were conducted to document existing cross-section 

geometry and changes in channel geometry over time. Surveys 

of the longitudinal profile were conducted to determine the 

elevations of channel features throughout the study reach. 

Pebble counts were conducted to determine grain-size distributions of the surficial bed material. Measuring point elevations from instream piezometers were used as the elevation 

control in selected cross-section locations to determine the net 

change in channel-bed elevation over time. High-water marks 

were measured at the streamgage and at selected downstream 

locations in the study reach to determine the water-surface 

slope during storm events (Doheny and others, 2007).
6 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Figure 3. Detailed view of Minebank Run watershed and study reach, Baltimore County, Maryland.
Methods of Data Collection 7

Figure 4. View looking upstream at unrestored section of Minebank Run in Cromwell Valley Park 

downstream of the Baltimore Beltway (I-695), 2003. (Refer to figure 6 for location of photograph.) 

(Photograph by Edward J. Doheny, U.S. Geological Survey.)

Figure 5. View looking upstream at restored section of Minebank Run in Cromwell Valley Park with 

original stream channel visible in the background, 2005. (Refer to figure 6 for location of photograph.) 

(Photograph by Kenneth Jewell, U.S. Environmental Protection Agency.)
8 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Figure 6. Location of continuous-record streamgage, crest-stage partial-record stations, precipitation gage, and well transects 

along the Minebank Run study reach, Baltimore County, Maryland.
Methods of Data Collection 9

Streamflow

Since October 2001, continuous-record streamflow 

data have been collected at USGS station 0158397967 in the 

Minebank Run study reach using standard USGS streamgaging techniques (Carter and Davidian, 1968; Buchanan and 

Somers, 1968; Doheny and others, 2007). Streamflow statistics for station 0158397967, Minebank Run near Glen Arm, 

Maryland for water years 2002 through 2008 are presented in 

table 1 (U.S. Geological Survey, 2009).

Precipitation

A precipitation gage was installed near the Minebank Run 

study reach to obtain continuous-record precipitation data that 

correspond to the Minebank Run streamgage located nearby 

(Doheny and others, 2006). Because the streamgage location 

was not suitable for monitoring precipitation due to an abundance of large trees in the vicinity of the station, the precipitation gage was installed in a row crop field approximately 

0.3 mi from the streamgage (fig. 6). Five-minute unit-value 

precipitation data were collected in this location beginning in 

October 2001. General station information for the precipitation 

gage was previously published in Doheny and others (2006).

Geomorphic monitoring in the Minebank Run study 

reach occurred during an alternating period of relatively wet 

and dry hydrologic conditions. Mean annual precipitation 

for the Baltimore region is about 42 in. (Maryland State 

Climatologist Office, 2011). On the basis of precipitation data 

collected in the vicinity of the Minebank Run study reach, 

total water year precipitation ranged from about 33 in. to more 

than 64 in. during the period of study (table 2) (Doheny and 

others, 2006).

Longitudinal Profiles

Longitudinal profiles of the Minebank Run study reach 

were conventionally surveyed on a yearly basis from April 

2002 through April 2008 to determine the relative elevations 

and consistency of the channel bed, water surface, and other 

channel features (Doheny and others, 2007). The reach where 

the longitudinal profile surveys were conducted was located 

in between the Sherwood Bridge and just upstream of the 

confluence with Harts Run (fig. 6). Channel-bed and watersurface elevations were surveyed along the study reach. All 

surveys were conducted using the same longitudinal stationing so that comparisons of profiles from different years would 

be possible. Survey elevations were measured at break points 

between riffles, pools, and runs in order to define these features individually. Distances were measured along the thalweg

between surveyed points on the streambed, which allowed 

definition of the lengths and distribution of riffles, pools, and 

runs in the reach (Doheny and others, 2007). The surveys 

from 2002 through 2004 represented the pre-restoration 

condition of the stream channel. The 2005 survey represented 

Table 1. Summary of streamflow statistics for U.S. Geological 

Survey station 0158397967, Minebank Run near Glen Arm, 

Maryland, water years 2002–08.

[mi2, square mile; ft3/s, cubic feet per second; [(ft3/s)/mi2], cubic feet per 

second per square mile]

Station 0158397967,

Minebank Run near

Glen Arm, Maryland

Drainage area (mi2) 2.06

Annual mean discharge (ft3/s) 2.81

Highest annual mean discharge (ft3/s) 4.34

(2004)

Lowest annual mean discharge (ft3/s) 1.15

(2002)

Highest daily mean discharge (ft3/s) 106

(October 8, 2005)

Lowest daily mean discharge (ft3/s) 0.04

(August 17, 2002)

Maximum instantaneous peak flow 

discharge (ft3/s)

1,400

(June 25, 2006)

Minimum instantaneous low flow 

discharge (ft3/s)

0.04

(August 17, 2002)

Annual runoff (inches) 18.51

Annual runoff [(ft3/s)/mi2] 1.36

Table 2. Total precipitation recorded in vicinity of the Minebank 

Run study reach during water years 2002 through 2008.

Water year Total precipitation 

(inches)

2002 32.95

2003 64.19

2004 51.70

2005 36.72

2006 60.30

2007 33.27

2008 54.22
10 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

the post-construction condition of the stream channel, 

approximately 1 month after the restoration work in the 

watershed was completed in February 2005. The surveys from 

2006 through 2008 represented the post-restoration condition 

of the stream channel. The methods and procedures used for 

the surveys are described in detail in Leopold (1994). Dates, 

locations, and longitudinal stationing used for the longitudinalprofile surveys are summarized in table 3.

Cross Sections

Permanent cross sections were established in the 

Minebank Run study reach to assess physical changes to 

the stream channel before and after restoration. Nine cross 

sections were established with monumented endpoints over 

a distance of approximately 1,300 ft prior to restoration, and 

approximately 1,260 ft after restoration. The reach contained 

the continuous-record streamgage, and the three transects 

of wells and piezometers that were established for other 

technical aspects of the study (fig. 6). The cross sections were 

established in straight sections of the channel, or in straight 

sections between meanders, and were aligned perpendicular 

to the direction of the streamflow. The cross sections were 

vertically referenced to NGVD 29. The cross sections were 

initially surveyed in December 2002 and re-surveyed during 

June and July of 2003, and again during January and February 

of 2004, just prior to the start of the channel restoration work 

that began in June 2004 (Doheny and others, 2007). Basic 

station information, including the longitudinal stationing, 

latitudes, and longitudes, for the nine permanent cross sections 

in the Minebank Run study reach prior to restoration can be 

found in Doheny and others (2007).

The cross sections were surveyed in April 2005 to 

document the post-construction geometry and dimension of 

the stream channel. The cross sections were re-surveyed in 

November and December 2005, September 2006, August 

2007, and April 2008 to document post-restoration conditions. 

Three cross-section endpoints were lost during the restoration 

work and had to be replaced, and two cross sections, Ee and 

Ii, had to be re-established in new locations after completion 

of the restoration work because sections of the stream channel 

were physically relocated (fig. 7). The new locations were 

within approximately 100 ft of the original cross sections. 

Basic station information including the post-restoration 

longitudinal stationing, latitudes, and longitudes, for the nine 

permanent cross sections in the Minebank Run study reach is 

summarized in table 4. 

Table 3. Dates, locations, and longitudinal stationing used for the longitudinal-profile surveys in the Minebank Run study reach, 

2002–08.

[ft, feet]

Date

of

survey

Starting

station

(ft)

Starting

location

Ending

station

(ft)

Ending

location

Reach

length

(ft)

April 16–17, 2002 5,000 Upstream side of Sherwood Bridge 3,358 In meander bend, approximately 330 

ft upstream of streamgage

1,642

March 31–April 1, 2003 5,000 Upstream side of Sherwood Bridge 3,283 In meander bend, approximately 290 

ft upstream of streamgage

1,717

April 23, 2004 5,000 Upstream side of Sherwood Bridge 3,337 In meander bend, approximately 280 

ft upstream of streamgage

1,663

March 30, 2005 4,975 Bottom of riffle, just above upstream 

side of Sherwood Bridge

3,213 At confluence with Harts Run 1,762

March 23–24, 2006 5,026 In riffle, under upstream side of 

Sherwood Bridge

3,219 At confluence with Harts Run 1,807

April 18, 2007 5,065 In riffle, under upstream side of 

Sherwood Bridge

3,136 Top of riffle, approximately 80 ft 

upstream from confluence with 

Harts Run 

1,929

April 10–11, 2008 5,045 Bottom of run, under upstream side 

of Sherwood Bridge

3,119 Top of riffle, approximately 100 ft 

upstream from confluence with 

Harts Run

1,926
Methods of Data Collection 11

Figure 7. Locations of permanent cross sections that were established and surveyed in the Minebank Run study 

reach at Cromwell Valley Park, 2002–08.
12 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Pebble Counts

One-hundred-particle pebble counts were conducted at 

each of the permanent cross section locations in the study 

reach to characterize the surficial channel-bed sediment over 

time. Pebble counts were initially conducted in May 2002 at 

the three well transects in the study reach that correspond to 

cross sections Ee, Ff, and Gg. A pebble count at all nine cross 

sections was conducted in May–June 2003 prior to restoration 

of the stream channel (Doheny and others, 2007). After restoration, pebble counts were conducted at the nine cross sections 

in May 2005, October 2006, and April 2008.

The pebble counts were made by randomly picking up 

particles from the channel bed throughout the entire width 

of the main channel at an interval of about 1 particle per foot 

of cross section, and measuring the intermediate axis, or 

width, of the particle that was picked up in mm (millimeters) 

(Leopold, 1994; Harrelson and others, 1994; Doheny and others, 2007). The particles were tallied according to size class 

(silt, sand, gravel, cobbles, or boulders) and used to directly 

determine grain-size distributions for the surface of the channel bed at each cross section and for the study reach (Doheny 

and others, 2007). An example of a grain-size distribution 

and computation of percent finer from a pebble count at 

cross section Ff in the Minebank Run study reach on May 9, 

2005 is shown in table 5. A plot of the grain-size distribution 

developed from the pebble count is shown in figure 8.

Bed-Elevation Measurements

Net changes in bed elevation were determined over time 

at three locations in the study reach where instream piezometers had been installed to monitor shallow groundwater levels 

and water quality (Mayer and others, 2003; Mayer and others, 

2010). These locations closely coincide with the locations of 

permanent cross sections Ee, Ff, and Gg (fig. 7). The distance 

from the top of the piezometers to the channel bed was measured every 1–2 months and after major storm events between 

December 2002 and July 2004. The instream piezometers were 

then removed in July 2004 as the instream work associated 

with the channel restoration was getting started. The instream 

piezometers were re-installed in the channel bed in September 

2005, several months after completion of the channel restoration work. The measurements from the top of the piezometers 

to the channel bed were then repeated in the three locations 

every 1–2 months and after major storm events between 

September 2005 and October 2008. Since the measuring point 

elevations were surveyed and related to NGVD 29, net bed 

elevations could be determined over time at the piezometer 

locations by making these periodic measurements (Doheny 

and others, 2007).

Table 4. Basic station information for permanent cross sections located in the Minebank Run study reach after restoration, 2005–08.

[ft, feet; °, degrees; ‘, minutes; “, seconds]

Cross

section

Longitudinal station

(ft)

Description of

cross section

location

Left 

cross section endpoint 

latitude-longitude

(° ‘ “)

Right 

cross section endpoint 

latitude-longitude

(° ‘ “)

Aa 4,727.0 Downstream of meander 39 24 42.6

76 33 14.8

39 24 41.1

76 33 13.5

Bb 4,668.0 Upstream of meander 39 24 42.1

76 33 15.8

39 24 42.4

76 33 13.8

Cc 4,533.0 Straight 39 24 41.1

76 33 16.7

39 24 40.4

76 33 14.5

Dd 4,394.0 Upstream of meander 39 24 40.2

76 33 18.0

39 24 38.9

76 33 16.2

Ee 4,234.0 Downstream of meander 39 24 38.5

76 33 18.5

39 24 37.9

76 33 17.5

Ff 3,990.0 Upstream of meander 39 24 37.8

76 33 20.4

39 24 36.5

76 33 19.4

Gg 3,839.0 Straight 39 24 37.0

76 33 22.3

39 24 36.3

76 33 21.3

Hh 3,678.0 Downstream of meander 39 24 35.8

76 33 24.0

39 24 35.1

76 33 23.2

Ii 3,463.0 Between two meanders 39 24 34.6

76 33 26.1

39 24 34.2

76 33 25.8
Watershed Hydrology 13

High-Water Marks

High-water marks were obtained in the study reach 

during water years 2002 through 2008 by use of crest-stage 

gages that were installed at selected locations (Buchanan and 

Somers, 1968). These marks were used along with electronically logged data from the continuous-record streamgage to 

determine peak water-surface elevations that occurred in the 

study reach between site visits. The crest-stage gages were serviced during regular maintenance visits to the streamgage and 

after major storm events. All high-water marks that were registered on the crest-stage gages were documented and logged. 

The hydrographs from the continuous-record streamgage were 

referenced to determine the date of the storm that left the highwater mark and the discharge associated with that storm. 

The distance between crest-stage gages along the thalweg 

of the stream channel was measured so that water-surface 

slopes could be determined at a range of stages and discharges 

by use of the high-water marks. Because the reach in the vicinity of the streamgage was the most linear section of the study 

reach, the streamgage and the crest-stage gage immediately 

downstream of this station were used for determination of 

representative water-surface slopes in the study reach (Doheny 

and others, 2007).

During the pre-restoration phase of the study, five creststage gages were used in selected locations of the study reach 

along with an additional one that was associated with the 

continuous-record streamgage (figs. 6, 7). All crest-stage gages 

downstream of well transect no. 3 were removed in 2004 prior 

to the channel restoration work, and were not replaced as the 

reach immediately downstream of the streamgage was deemed 

most critical for determining representative water-surface 

slopes in the study reach.

Watershed Hydrology

For comparisons of various geomorphic characteristics 

in the pre- and post-restoration periods of the overall study to 

be meaningful, some hydrologic context for the study period 

must be provided. In this way, it is possible to determine 

whether noted changes may have been caused by implementation of the channel-restoration design, changes in hydrologic 

conditions, or both. Basic watershed characteristics, such as 

drainage area and basin slope, did not change appreciably during the study period. Land-use type and distribution were also 

unchanged, as the watershed is located in a small area of builtout residential and commercial development and protected 

park land (Baltimore County Department of Environmental 

Protection and Resource Management, 2000). As a result, 

these watershed characteristics were not considered as potential causes of any hydrologic or geomorphic changes observed 

in the stream channel during the study period. Precipitation, 

discharge intensity, time of concentration, flood frequency, 

and rainfall-runoff relations were investigated for the study 

period to provide some hydrologic context to the geomorphic 

monitoring that was conducted between 2002 and 2008.

Table 5. Grain-size distribution and computation of percent finer from pebble count at cross 

section Ff, Minebank Run study reach, May 9, 2005.

[mm, millimeters; %, percent, ---, not applicable]

Particle

description

Particle

size limit

(mm)

Item

count

Cumulative

percent finer

(%)

Silt 0.062 0 0

Sand 2 4 4.0

Very fine gravel 4 0 4.0

Fine gravel 8 4 7.9

Medium gravel 16 12 19.8

Coarse gravel 32 20 39.6

Very coarse gravel 64 26 65.3

Small cobbles 128 31 96.0

Large cobbles 256 4 100.0

Small boulders 512 0 100.0

Medium boulders 1,024 0 100.0

Large boulders 2,048 0 100.0

Very large boulders 4,096 0 100.0

TOTAL --- 101 ---
14 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Figure 8. Plot of grain-size distribution developed from the 

pebble count at cross section Ff, Minebank Run study reach, 

May 9, 2005.

Precipitation

There is considerable annual variation in the precipitation 

input and streamflow output from Minebank Run as shown 

by data presented in tables 1 and 2. During the study period, 

the watershed received the largest amount of precipitation 

during water year 2003, but produced the largest annual mean 

discharge of 4.34 ft3

/s (cubic feet per second) during water 

year 2004 (which experienced the median annual precipitation 

for the study period). Annual mean discharge during water 

year 2003 was 4.26 ft3

/s, or approximately 1.9 percent less 

than water year 2004, despite nearly 12.5 additional in. of 

precipitation that fell during water year 2003. The explanation 

for this occurrence is that each of the other three water years 

(2003, 2006, and 2008) with larger, above-average (47.62 in.) 

annual precipitation was immediately preceded by years with 

below-average annual precipitation. During the study, only 

water year 2004 experienced both above-average precipitation 

and succeeded a year of above-average precipitation.

The effects of annual variability notwithstanding, data 

from table 2 indicate that the variation in annual precipitation 

totals was comparable for the pre- and post-restoration periods. Similarly, storm durations, intensities, and precipitation 

totals were comparable during the two study periods. Storm 

durations in both periods ranged from a half hour to several 

days. Maximum storm intensity recorded during water years 

2002 through 2004 was 4.68 in/h (inches per hour) (0.39 in. 

during one 5-minute period on April 19, 2002), whereas the 

maximum intensity during water years 2005 through 2008 

was 4.08 in/h (0.34 in. during one 5-minute period on July 23, 

2008). It should be noted that several high-intensity and longduration precipitation events were not recorded during the 

post-restoration period because of several equipment malfunctions, so exact data values to define the full range of conditions during that time are not available. In these cases, daily 

precipitation totals were estimated using data from two nearby 

non-recording precipitation gages that were placed in the field 

to provide back-up data to the recording gage.

Discharge Intensity

Doheny and others (2006) quantified flashy streamflow 

in Minebank Run during water years 2002 through 2004 by 

comparing a ratio of peak discharge to daily-mean discharge 

for flood events. For purposes of this discussion, construction 

work in the study reach section of the watershed was completed around December 2004, and the boundary between 

the pre- and post-restoration periods for the study reach was 

considered to be between approximately December 2004 

and February 2005. The pre-restoration period peak discharges used in this analysis ranged from 247 ft3

/s to 1,390 

ft3

/s, whereas daily-mean discharges ranged from 8.0 ft3/s to 

50 ft3

/s. The maximum ratio for a storm in this time period 

was 51.4, occurring on May 17, 2004. By comparison, in the 

post-restoration period from approximately February 2005 

through September 2008, peak discharges ranged from 214 

ft3

/s to 1,400 ft3/s, daily-mean discharges ranged from 5.8 ft3/s 

to 106 ft3

/s, and the maximum ratio was 40.9. For purposes of 

comparison, only peak discharges greater than 200 ft3

/s were 

considered in this analysis.

Because the timing of precipitation events can sometimes cause the peak discharge from a storm to occur on the 

day before the majority of the storm runoff occurs, a more 

useful measure of streamflow flashiness is the ratio between 

peak discharge and the event-mean discharge. The ranges of 

event-mean discharges for the peak-discharge events used to 

describe streamflow flashiness were 51 ft3

/s to 135 ft3/s during 

the pre-restoration period, and 40 ft3

/s to 134 ft3/s during the 

post-restoration period. The maximum ratios of peak discharge 

and event-mean discharge are 11.6 (June 12, 2003) and 10.5 

(June 25, 2006) for the pre- and post-restoration periods, 

respectively.

The relations between instantaneous peak discharges and 

both the daily-mean and event-mean based ratios described 

here are shown in figure 9. Comparison of the respective coefficients of determination, R2

, shows that the relations between 

instantaneous peak discharge and its ratio with the event-mean 

discharge is more linear than that with the daily-mean discharge ratio in both the pre-restoration and post-restoration 

periods. It is also evident that neither relation appears to have 

changed considerably during the full study period, so stream 

flashiness in Minebank Run was not affected by the physical 

restoration of the stream channel.

Time of Concentration

In Doheny and others (2006), times of concentration

were calculated for 18 selected precipitation events that 

occurred within the pre-restoration monitoring period between 

November 2001 and July 2004, using precipitation data from 

the recording precipitation gage near the study reach and 

USGS streamgage 0158397967, Minebank Run near Glen 

Arm, Maryland. The hydrologic response characterized by the 

time of concentration for these events varied from 5 minutes 

to 90 minutes, and included events displaying a range of durations and intensities.
Watershed Hydrology 15

The data that were presented in Doheny and others 

(2006) describing the 18 selected events are included in table 

6. The table also includes data from 20 additional post-restoration events that occurred in the Minebank Run watershed 

between March 2005 and July 2008, calculated using the same 

data sources as those used in the pre-restoration period, as 

well as times of concentration for the same events in the West 

Branch Herring Run watershed. These values were calculated 

using data from the same recording precipitation gage and 

USGS streamgage 01585200, West Branch Herring Run at 

Idlewylde, Maryland. The West Branch Herring Run watershed monitored by this streamgage is of similar size (2.13 mi2

) 

and shape to the monitored section of Minebank Run. The two 

watersheds are adjacent, sharing a boundary at their respective 

headwaters (fig. 10). Unlike Minebank Run, the West Branch 

Herring Run stream channel had not undergone any restoration 

work during the study period, and is characterized by trapezoidal concrete lining over much of its monitored length. This 

condition provides a contrast to the channel conditions seen in 

Minebank Run, both before and after restoration, and can also 

be used to identify any effects on watershed response relating 

to environmental conditions rather than restoration activities.

A plot of maximum rainfall intensity against time of concentration for Minebank Run and West Branch Herring Run 

for selected pre-and post-restoration storm events is shown in 

figure 11. In almost all cases, the times of concentration for 

West Branch Herring Run are less than those for Minebank 

Run. The times of concentration for West Branch Herring Run 

also fall within a narrower range than those for Minebank 

Run. This is not unexpected given that the smooth-lined, concrete channel characteristic of the monitored section of West 

Branch Herring Run should be a more efficient runoff conduit 

than the unlined channel of Minebank Run. On the basis of 

this analysis, the ranges of the times of concentration for both 

sites can be considered comparable for both the pre- and postrestoration monitoring periods.

Figure 9. Relations between instantaneous peak discharge and ratios of daily-mean and event-mean discharges, pre- and postrestoration, at station 0158397967, Minebank Run near Glen Arm, Maryland.
16 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Table 6. Time of concentration for 38 selected storms in the Minebank Run and West Branch Herring Run watersheds, water years 

2002 through 2008 (modified from Doheny and others, 2006).

[EST, Eastern Standard Time; hrs, hours; in., inches; in/h, inches per hour; min, minutes]

Date(s)

of

storm

Time

(EST)

Storm 

duration

(hrs)

Storm 

rainfall total

(in.)

Average 

rainfall 

intensity

(in/h)

Maximum

rainfall

intensity

(in/h)

Minebank Run

time of

concentration

(min)

West Branch 

Herring Run

time of

concentration

(min)

November 25, 2001 1610–1935 3.42 1.80 0.53 2.88 10 5

April 18, 2002 1350–1655 3.08 0.93 0.30 2.76 25 30

April 19, 2002 1515–1550 0.58 0.80 1.38 4.68 5 30

April 27–28, 2002 2155–1055 13.00 1.57 0.12 0.48 90 5

May 2, 2002 0200–0725 5.42 0.98 0.18 1.92 65 5

June 6, 2002 1655–1720

1735–1800

0.83 1.06 1.28 3.12 20 5

August 3, 2002 0050–0150 1.00 1.18 1.18 3.24 10 20

October 10–11, 2002 0535–1255 31.33 3.06 0.10 1.32 45 20

February 22, 2003 0610–1440 8.50 2.13 0.25 1.68 50 20

June 12, 2003 1620–1820

1910–2025

3.25 2.27 0.70 3.48 10 5

June 13, 2003 1835–1945 1.17 0.81 0.69 3.12 5 5

August 4, 2003 0155–0945 7.83 0.64 0.08 0.60 15 5

September 18–19, 2003 1310–0115 12.08 0.64 0.05 0.48 72 20

September 22–23, 2003 1905–0715 12.17 3.15 0.26 2.04 80 15

October 14–15, 2003 1840–-0020 5.67 2.07 0.37 3.00 35 5

November 19, 2003 1315–2130 8.25 2.09 0.25 3.60 5 15

June 25, 2004 1520–1645 1.42 0.75 0.53 2.28 40 5

July 7, 2004 1405–1655 2.83 1.92 0.68 2.52 40 25

March 23, 2005 0255–1510 12.25 1.87 0.15 0.48 10 5

March 28, 2005 0850–1455 6.08 1.09 0.18 1.20 40 10

July 7–8, 2005 1945–0935 13.83 2.62 0.19 1.80 110 40

November 29, 2005 2030–2325 2.92 0.95 0.33 1.80 60 15

December 25, 2005 1125–1725 6.00 1.08 0.18 0.96 55 10

February 4, 2006 1115–2140 10.42 1.03 0.10 0.96 70 30

May 11, 2006 1930–2225 2.92 1.05 0.36 2.76 10 10

June 2–3, 2006 2020–0245 6.42 2.33 0.36 0.96 15 5

June 19, 2006 1510–1530 0.33 0.55 1.67 2.52 5 5

July 5–6, 2006 1940–0100 5.33 2.90 0.54 2.52 30 5

July 22, 2006 1610–1705 0.92 0.93 1.01 3.00 15 15

September 15, 2006 1305–1515 2.17 0.91 0.42 1.08 25 30

July 10, 2007 1220–1400 1.67 0.60 0.36 1.92 35 30

August 20, 2007 1730–1825 0.92 0.61 0.67 0.60 5 5

December 2, 2007 2145–2345 2.00 0.61 0.31 0.60 35 45

April 20, 2008 1040–1135 0.92 0.97 1.05 2.40 5 10

May 11–12, 2008 2015–0505 8.83 1.35 0.15 0.48 30 45

June 4, 2008 1455–1525 0.50 0.60 1.20 2.52 25 5

July 13, 2008 1700–1720 0.33 0.45 1.36 3.00 35 5

July 23, 2008 2005–2125 1.33 2.15 1.62 4.08 30 10
Watershed Hydrology 17

Figure 10. Locations and contributing areas of watersheds 

draining to station 01585200, West Branch Herring Run at 

Idlewylde, Maryland and station 0158397967, Minebank Run 

near Glen Arm, Maryland.

Figure 11. Maximum rainfall intensity against time of concentration for Minebank Run and West Branch 

Herring Run for selected pre- and post-restoration storm events, water years 2002 through 2008.
18 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Flood Frequency 

Estimated flood-frequency characteristics for Minebank 

Run at USGS streamgage 0158397967, Minebank Run near 

Glen Arm, Maryland were presented in Doheny and others 

(2006), based on discharge data collected during water 

years 1997 through 2004 (Interagency Advisory Committee 

on Water Data, 1982). The streamgage began operation in 

water year 2002, so the amount of data from the station that 

can be used in this analysis (7 years) is relatively limited. 

In Doheny and others (2006), the authors augmented the 

peak-discharge data at the subject site with information from 

another streamgage further downstream on Minebank Run 

(station 01583980, Minebank Run at Loch Raven, Maryland), 

and compared the estimates with those from a streamgage 

in a less-developed watershed of similar size and slope 

in Baltimore County (station 01583000, Slade Run near 

Glyndon, Maryland). Data from the streamgage on Minebank 

Run now includes information from water years 2005 through 

2008 in the post-restoration monitoring period. Using the additional data, a different approach has been used to revise the 

estimated flood-frequency characteristics for the study reach.

For this approach, peak-discharge data from the 

streamgage on West Branch Herring Run at Idlewylde, 

Maryland was used in conjunction with data from the study 

reach at Minebank Run to provide more confidence in the 

flood-frequency estimates. The linear relation between logtransformed post-restoration (water years 2005 through 2008) 

annual-peak discharges at Minebank Run and coincident 

peaks at West Branch Herring Run is shown in figure 12. The 

relation is very strong, with an R2 of 0.98. Although there are 

only four data points in the analysis, it provides confidence 

that the relation between peaks at the two sites can be used 

to extrapolate information from West Branch Herring Run to 

improve understanding of the flood-frequency characteristics 

at Minebank Run based on a considerably longer peak flow 

record. This goal was accomplished by estimating the floodfrequency characteristics at West Branch Herring Run using 

the full dataset from that site (water years 1958 to 1987, and 

1997 to 2008), and normalizing those estimates to Minebank 

Run based on the average ratio of the four coincident peaks 

plotted in figure 12. On average, the peak discharge at 

Minebank Run was found to be about 76 percent as large as 

the corresponding peaks from West Branch Herring Run. The 

resulting normalized, long-term flood-frequency estimates for 

Minebank Run are shown in table 7, along with the original 

estimates from Doheny and others (2006).

The normalized, long-term flood-frequency estimates for 

Minebank Run predict considerably smaller discharges for all 

intervals of annual exceedance probability (table 7). This indicates that the largest peak flows that occurred in the Minebank 

Run watershed during the monitoring period could represent 

events of lower probability when compared to the considerably longer peak-flow record in the West Branch Herring Run 

watershed.

Rainfall-Runoff Relations

Doheny and others (2006) quantified rainfall-runoff relations by listing the percentage of rainfall that was conveyed 

as runoff for 18 selected precipitation events that occurred 

between November 2001 and July 2004 as part of the prerestoration monitoring period. Percentages ranged from 11.8 to 

60.0 for the selected events, with an average of 29.7 percent. 

The wide range of percentages was thought to be caused by 

the range of precipitation and soil moisture conditions during 

the period, which included drought in 2002, followed by 2 

years of above-average precipitation.

Information on an additional 23 post-restoration 

precipitation events that occurred between March 2005 and 

July 2008 add to the data presented by Doheny and others 

(2006) and is shown in table 8. The percentage of rainfall that 

is conveyed as runoff in the post-restoration monitoring period 

ranges from 9.8 to 44.4, with an average of 19.4 percent. 

Although this period is not considered to have been particularly dry from an annual precipitation standpoint, it is characterized by long periods of little or no rainfall punctuated by a 

handful of large precipitation events. This may explain why 

the percentages are considerably lower than the average from 

the pre-restoration period.

Figure 12. Linear relation between log-transformed annual 

peak discharges at Minebank Run and coincident peaks at 

West Branch Herring Run.
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 19

Comparison of Pre- and PostRestoration Geomorphic 

Characteristics 

Geomorphic data collected during water years 2002 

through 2008 were used to track changes occurring over time 

and compare pre-restoration and post-restoration geomorphic 

characteristics in the Minebank Run study reach (Doheny and 

others, 2007). Geomorphic characteristics that were tracked 

over time and compared included (1) longitudinal profiles 

of the channel bed and water surface; (2) changes in crosssection geometry; (3) hydraulic-geometry relations between 

cross-sectional area, mean channel depth, channel width, and 

mean velocity and discharge; (4) grain-size analyses of the 

channel bed; (5) net changes in the elevation of the channel 

bed at selected locations over time; (6) analyses of boundary 

shear stress based on cross-section geometry and water-surface 

slope in the vicinity of the streamgage; and (7) net changes in 

estimated sediment volume in the study reach. 

Longitudinal Profiles

Longitudinal profiles of the channel bed, water surface, 

and other channel features were developed for the Minebank 

Run study reach on the basis of yearly field surveys that were 

conducted between April 2002 and April 2008. Slopes of the 

channel bed and water surface were determined by use of 

simple linear regression. Percentages of riffles, pools, and runs 

were determined for each profile based on the stream length 

of each feature relative to the length of the surveyed reach. 

The profiles also were analyzed to determine differences in the 

distribution and location of riffles, pools, and runs throughout 

the study reach over time (Doheny and others, 2007). An 

aerial view of the study reach used for the longitudinal surveys 

is shown in figure 13 (Baltimore County Department of 

Environmental Protection and Resource Management, 2000). 

An example plot of the longitudinal profile that was developed 

from the March 30, 2005 survey is shown in figure 14. 

Pre-restoration surveys conducted between 2002 and 

2004 indicated a distinct and extensive series of point bar and 

terrace features in the main channel along the study reach. 

Table 7. Comparison of flood-frequency analyses for Minebank Run, based on station data from 1997–2004 and normalized from longterm estimates at West Branch Herring Run (modified from Doheny and others, 2006).

[yrs, years; ft3/s, cubic feet per second]

Annual 

exceedance 

probability

Recurrence 

interval

(yrs)

Discharge for 

U.S. Geological Survey station 

number 0158397967, Minebank 

Run near Glen Arm, Maryland1

(1997–2004)

(ft3

/s)

Discharge for U.S. Geological Survey station 

number 0158397967, Minebank Run near Glen 

Arm, Maryland, normalized based on estimates 

from station 01585200, West Branch Herring Run 

at Idlewylde, Maryland (1958–1987, 1997–2008) 

(ft3

/s)

0.995 1.005 252.2 109.4

0.990 1.01 283.7 125.6

0.950 1.05 394.4 185.6

0.900 1.11 472.1 230.2

0.800 1.25 589.4 301.0

0.500 2 912.7 513.8

0.200 5 1,437.0 903.3

0.100 10 1,835.0 1,228.0

0.040 25 2,393.0 1,718.0

0.020 50 2,849.0 2,146.0

0.010 100 3,339.0 2,630.0

0.005 200 3,867.0 3,176.0

0.002 500 4,631.0 4,008.0

1

 Peak-discharge record for flood-frequency analysis estimated using drainage area ratios from U.S. Geological Survey station 01583980, Minebank Run at 

Loch Raven, Maryland for water years 1997 through 2001.
20 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Table 8. Runoff amounts and percentages for 41 selected storm events at U.S. Geological Survey station 0158397967, Minebank Run 

near Glen Arm, Maryland, water years 2002 through 2008.

[hrs, hours; in., inches; ft3/s, cubic feet per second; ft3, cubic feet]

Date(s) of storm

Storm 

duration

(hrs)

Storm rainfall 

total

(in.)

Peak 

discharge

(ft3/s)

Flood

volume

(ft3)

Runoff

amount

(in.)

Percentage of 

total rainfall as 

runoff

November 25, 2001 3.42 1.80 367 1,451,000 0.30 16.7

April 18, 2002 3.08 0.93 180 540,000 0.11 11.8

April 19, 2002 0.58 0.80 401 834,900 0.17 21.3

April 27-28, 2002 13.00 1.57 78 1,265,600 0.26 16.8

May 2, 2002 5.42 0.98 247 1,038,100 0.22 22.1

June 6, 2002 0.83 1.06 466 1,133,600 0.24 22.3

August 3, 2002 1.00 1.18 725 1,641,100 0.34 29.1

October 10–11, 2002 31.33 3.06 197 3,021,300 0.63 20.6

February 22, 2003 8.50 2.13 253 4,871,900 1.02 47.8

June 12, 2003 3.25 2.27 1,390 4,933,400 1.03 45.4

June 13, 2003 1.17 0.81 730 1,529,400 0.32 39.5

August 4, 2003 7.83 0.64 248 611,500 0.13 20.0

September 18–19, 2003 12.08 0.64 256 1,838,900 0.38 60.0

September 22–23, 2003 12.17 3.15 834 5,067,700 1.06 33.6

October 14–15, 2003 5.67 2.07 411 2,555,300 0.53 25.6

November 19, 2003 8.25 2.09 700 3,464,800 0.72 34.6

June 25, 2004 1.33 0.75 295 1,251,720 0.26 34.9

July 7, 2004 2.67 1.92 945 3,052,250 0.64 33.2

March 23, 2005 12.25 1.87 99 2,855,700 0.60 32.1

March 28, 2005 6.08 1.09 227 1,800,900 0.38 34.9

July 8, 2005 13.83 2.62 231 1,270,200 0.27 10.3

October 7–8, 2005 39.75 10.92 883 9,157,800 1.91 17.5

November 29, 2005 2.92 0.95 119 842,400 0.18 18.9

December 25, 2005 6.00 1.08 112 841,500 0.18 16.7

February 4, 2006 10.42 1.03 138 840,000 0.18 17.5

May 11, 2006 2.92 1.05 214 864,000 0.18 17.1

June 2, 2006 6.42 2.33 770 2,481,600 0.52 22.3

June 19, 2006 0.33 0.55 111 302,400 0.06 10.9

June 25–26, 2006 11.75 2.00 1,400 4,251,600 0.89 44.4

July 5, 2006 5.33 2.90 370 2,910,600 0.61 21.0

July 22, 2006 0.92 0.93 167 459,000 0.10 10.8

September 15, 2006 2.17 0.91 176 1,192,800 0.25 27.5

July 10, 2007 1.67 0.60 237 420,000 0.09 15.0

August 20, 2007 0.92 0.61 98 304,200 0.06 9.8

October 10, 2007 1.17 0.64 87 313,500 0.07 10.9

December 2–3, 2007 2.00 0.61 71 580,400 0.12 19.7

April 20, 2008 0.92 0.97 214 521,800 0.11 11.2

June 3, 2008 1.50 0.60 74 324,100 0.07 11.7

June 4, 2008 0.50 0.60 84 266,100 0.06 10.0

July 7, 2008 0.67 0.75 265 799,900 0.17 22.7

July 23, 2008 1.33 2.15 883 3,523,900 0.74 34.4
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 21

Figure 13. Aerial photograph showing Minebank Run study reach in Cromwell Valley Park prior to channel restoration.

Figure 14. Longitudinal profile of channel features in the Minebank Run study reach from field survey conducted on March 30, 2005.
22 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

The presence of these features indicates that the channel bed 

had degraded and widened over time, and abandoned its flood 

plain at least twice due to degradation in the pre-restoration 

state (Doheny and others, 2007). Post-restoration surveys 

also indicated evidence of the point bar and terrace features 

throughout the study reach (fig. 14), as they were either left in 

place in areas of the study reach that were undisturbed by the 

restoration work, or implemented into the restoration design 

for re-establishing a flood plain for the stream channel. 

Slopes were computed for the channel bed and water 

surface for each of the seven longitudinal profiles surveyed 

between April 2002 and April 2008. The results are shown in 

table 9.

Slopes for the channel bed and water surface were 

approximately 1 percent or slightly less as shown in table 9. 

The survey in March 2005 is representative of the post-construction condition just after the stream restoration work was 

completed in February 2005. Whereas the restored channel 

bed and water surface slopes are slightly less than those 

found prior to restoration, these slopes have been maintained 

at almost the same percentage that was determined just after 

completion of the restoration work in 2005, despite six major 

storm events that hit the watershed during water years 2006 

through 2008.

Data from the longitudinal profile surveys also were analyzed to determine the percentages of riffles, pools, and runs in 

the study reach and whether these percentages and distribution 

remain consistent over time. The percentages of riffles, pools, 

and runs in the Minebank Run study reach that were determined from the longitudinal-profile surveys between 2002 

and 2008 are shown in table 10. The distribution and percentages of riffles, pools, and runs that were determined from the 

longitudinal-profile surveys between 2002 and 2008 are shown 

in figure 15.

Based on the pre-restoration surveys that were conducted 

prior to 2005, noticeable changes were evident in the percentages and distribution of riffles, pools, and runs in the study 

reach (Doheny and others, 2007). The changes in percentages 

of riffles, pools, and runs between 2002 and 2004 indicated 

that, on average, different sections of the stream channel 

were going through alternating periods of scour and fill over 

time (Doheny and others, 2007). Increasing riffle and run 

percentages with corresponding decreases in pool percentages between 2002 and 2003 indicated that sediment storage 

was increasing in the study reach during this period of time. 

Increasing pool percentages with a corresponding decrease in 

run percentages between 2003 and 2004 indicated that sediment storage was decreasing in the study reach during this 

period of time (Doheny and others, 2007).

When the stream restoration was completed in 2005, 

the longitudinal profile from that year indicated that the 

stream channel was considerably more riffle-dominated with 

lesser percentages of pools. The longitudinal profiles from 

2006 through 2008 showed a considerable reduction in riffle 

percentages from riffle percentages found in 2005, with a 

greater balance of pool and run percentages in the study reach. 

Table 9. Slopes of the channel bed and water surface in the 

Minebank Run study reach from longitudinal profile surveys, 

2002–08 (modified from Doheny and others, 2007).

Date of 

survey

Channel 

bed

Water 

surface

April 16, 2002 0.0101 0.0100

March 31–April 1, 2003 0.0093 0.0092

April 23, 2004 0.0095 0.0095

March 30, 2005 0.0088 0.0088

March 23–24, 2006 0.0087 0.0090

April 18, 2007 0.0088 0.0088

April 10–11, 2008 0.0091 0.0092

Table 10. Percentages of riffles, pools, and runs in the 

Minebank Run study reach from longitudinal-profile surveys, 

2002–08 (modified from Doheny and others, 2007).

[%, percent]

Date of 

survey

Riffle 

(%)

Pool 

(%)

Run 

(%)

April 16, 2002 42.2 42.3 15.5

March 31–April 1, 2003 52.2 27.5 20.3

April 23, 2004 52.4 39.9 7.7

March 30, 2005 73.8 12.3 13.9

March 23–24, 2006 38.2 31.9 29.9

April 18, 2007 42.1 22.0 35.8

April 10–11, 2008 39.1 38.5 22.4

Between 2006 and 2008, riffle percentages ranged from 38.2 

to 42.1 percent. These percentages are very similar in magnitude to the percentage of 42.2 percent that was determined 

based on the 2002 survey. Pool percentages continued to show 

an alternating pattern of increases and decreases between 2006 

and 2008, which indicates a continuing pattern of scour and fill 

in the study reach over time. Percentages of runs were larger 

based on the 2006–08 surveys than in 2005, immediately after 

completion of the stream restoration project. Run percentages 

also showed an alternating pattern of increases and decreases 

each year, but opposite of the pattern shown in pool percentages. This indicates that, on average, the channel was scouring 

and storing less sediment between 2005 and 2006. The channel was filling and storing more sediment between 2006 and 

2007, and scouring again between 2007 and 2008.

Comparison of the profiles over time indicated considerable differences in the distribution and location of riffles, 

pools, and runs in the study reach each year (Doheny and 

others, 2007). This pattern is evident in both the pre- and 

post-restoration monitoring periods (fig. 15). In both the 

pre-restoration and post-restoration monitoring periods, the 

analyses indicated that, on average, the stream is maintaining 
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 23

Figure 15. Comparison of riffle, pool, and run distribution and percentages in the Minebank Run study reach before and after channel 

restoration, 2002 through 2008.
24 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

the overall slope of the channel bed and water surface in the 

study reach, despite considerable changes in the percentages 

of riffles, pools, and runs, and changes in the distribution and 

location of these features within the reach.

Cross-Section Geometry

Pre-restoration channel geometry at the nine permanent 

cross sections was determined on the basis of field surveys 

conducted in December 2002, June–July 2003, and in 

January–February 2004 (Doheny and others, 2007). Postrestoration channel geometry at the nine permanent cross 

sections was determined on the basis of field surveys conducted in April 2005, November–December 2005, September 

2006, August 2007, and April 2008. Each cross section was 

plotted for the three pre-restoration surveys and the five postrestoration surveys to determine the changes in bed elevation 

and channel alignment over time. Cross-sectional area, wetted 

perimeter, hydraulic radius, channel width, and mean channel depth were determined for each cross section at a range of 

water-surface elevations, and compared to document changes 

that occurred between field surveys (Doheny and others, 

2007). Plots of the nine permanent cross sections and crosssection geometry prior to restoration were previously published in Doheny and others (2007).

On the basis of geomorphic conditions that were interpreted from changes in the cross sections during the pre-restoration monitoring period, cross sections Bb and Ee appeared to 

be primary areas for sediment storage within the study reach. 

Cross section Ee appeared to store large volumes of sediment for short periods of time and was vertically and laterally 

unstable. Cross section Bb showed net aggradation of the 

channel bed over time with small amounts of lateral erosion. 

Cross sections Aa, Cc, and Hh also showed indications of temporary sediment storage and removal over time. Cross sections 

Aa, Dd, Ee, Ff, and Ii appeared to be the most unstable cross 

sections in the study reach, due to either considerable lateral 

erosion, erosion of the channel bed, or both. Cross section 

Gg appeared to be laterally unstable with a lesser degree of 

vertical instability. On the basis of the locations of cut banks 

and lateral erosion in the study reach, the stream channel was 

actively adjusting its meander pattern and trying to increase its 

sinuosity prior to restoration (Doheny and others, 2007).

Plots of the nine permanent cross sections (Aa–Ii) after 

restoration are shown in figures 16–24. Cross-section geometry at a range of water-surface elevations was determined 

at all nine permanent cross-section locations. A comparison 

of cross-section geometry for cross-section Hh from the five 

post-restoration field surveys conducted during 2005 through 

2008 is shown in table 11. Post-restoration comparisons 

for each of the other eight permanent cross sections in the 

Minebank Run study reach are included in Appendix 1.

A net decrease in cross-sectional area, hydraulic radius, 

and mean depth over time is evident at cross section Hh (table 

11). Channel width and wetted perimeter showed net increases 

at most elevations over time. The cross-section surveys also 

indicated alternating increases and decreases in cross-sectional 

area and mean depth during different periods of time, which 

could indicate alternating degradation and aggradation of the 

channel bed resulting from temporary storage and removal 

of sand and gravel during storm events (Doheny and others, 

2007). These changes were generally more variable during 

2005–06 and less variable during 2006–08. Even with considerable lateral erosion on the right side of the channel due to 

erosion of a point bar, the cross-sectional area is still showing 

a net decrease over time due to considerable aggradation of the 

bed on the left side of the channel.

These analyses were performed for all permanent cross 

sections in the Minebank Run study reach, and used to 

develop an overall assessment of channel geometry changes 

in the study reach that occurred between April 2005 and April 

2008. The results are summarized in table 12. 

At cross section Aa, the relatively small net increases and 

decreases in cross-sectional area and mean depth with minimal amounts of lateral erosion and thalweg shifting indicate 

a relatively stable cross section. The periods of alternating 

increases and decreases in cross-sectional area and mean depth 

indicate a pattern of storage and removal of sand and gravel 

at this location during storms, but with more variability in the 

first 1.0 to 1.5 years after completion of the restored stream 

channel. 

At cross section Bb, the net increases in cross-sectional 

area and mean depth with minimal amounts of lateral erosion 

indicate channel incision over time in this section. Cross 

section Bb also does not appear to be a primary location for 

sediment storage, based on the pattern of gradually lower bed 

elevations over time and no clear pattern of any alternating 

increases and decreases in cross-sectional area or mean depth.

Cross section Cc showed net increases in cross-sectional 

area and mean depth at most elevations, with more considerable net increases within the main channel below elevations of 

215.50 ft. The net increases in cross-sectional area and mean 

depth in the main channel, along with periods of alternating 

increases and decreases between surveys, could indicate that 

sand and gravel could be temporarily stored in this location 

after certain storm events despite overall degradation during 

the post-restoration monitoring period.

Cross section Dd showed net increases in cross-sectional 

area over time at all elevations, and in mean depths at lower 

elevations. The net increases in cross-sectional area, and 

in mean depth at lower elevations, along with alternating 

increases and decreases between surveys indicates that sand 

and gravel could be temporarily stored in this location after 

certain storm events despite overall degradation during the 

post-restoration monitoring period. Increasing elevations on 

the right overbank indicate that overbank flows may have 

deposited a 0.10–0.20-ft depth of fine sediment in the overbank area between 2005 and 2008. 

Cross section Ee showed net increases in mean channel 

depth, shifting channel thalweg, and net decreases in channel 

width. This indicates channel incision in this section, along 
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 25

Figure 16. Post-restoration cross-section geometry at permanent cross section Aa, April 2005 through April 2008.

Figure 17. Post-restoration cross-section geometry at permanent cross section Bb, April 2005 through April 2008.

Figure 18. Post-restoration cross-section geometry at permanent cross section Cc, April 2005 through April 2008.
26 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Figure 19. Post-restoration cross-section geometry at permanent cross section Dd, April 2005 through April 2008.

Figure 20. Post-restoration cross-section geometry at permanent cross section Ee, April 2005 through April 2008.

Figure 21. Post-restoration cross-section geometry at permanent cross section Ff, April 2005 through April 2008.
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 27

Figure 22. Post-restoration cross-section geometry at permanent cross section Gg, April 2005 through April 2008.

Figure 23. Post-restoration cross-section geometry at permanent cross section Hh, April 2005 through April 2008.

Figure 24. Post-restoration cross-section geometry at permanent cross section Ii, April 2005 through April 2008.
28 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Table 11. Changes in cross-section geometry at permanent cross-section Hh, Minebank Run study reach, 2005 through 2008.

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Nov., November; %, percent]

Elevation

(ft

above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

222.00 57.7 66.6

(+15.4%)

48.1

(-16.6%)

45.0

(-22.0%)

47.9

(-17.0%)

33.6 36.0 37.2 36.1 36.5

222.50 74.2 84.1

(+13.3%)

66.3

(-10.6%)

63.2

(-14.8%)

66.3

(-10.6%)

35.1 38.0 39.6 38.2 38.5

223.00 91.6 102.2

(+11.6%)

85.5

(-6.7%)

82.3

(-10.2%)

85.5

(-6.7%)

38.5 39.7 41.8 40.2 40.5

223.50 113.6 121.3

(+6.8%)

106.1

(-6.6%)

102.8

(-9.5%)

106.3

(-6.4%)

46.4 42.2 47.5 46.4 46.5

224.00 136.2 145.5

(+6.8%)

128.8

(-5.4%)

125.6

(-7.8%)

129.4

(-5.0%)

50.3 51.6 50.0 48.5 48.9

224.50 160.3 169.8

(+5.9%)

152.8

(-4.7%)

149.5

(-6.7%)

153.5

(-4.2%)

52.0 52.9 52.4 51.1 51.4

225.00 185.0 194.5

(+5.1%)

177.7

(-3.9%)

174.6

(-5.6%)

178.8

(-3.4%)

53.8 54.6 54.5 53.7 53.7

225.50 210.5 220.2

(+4.6%)

203.5

(-3.3%)

200.8

(-4.6%)

205.2

(-2.5%)

56.4 57.4 57.0 56.2 57.2

225.78 225.6 235.3

(+4.3%)

218.7

(-3.1%)

216.2

(-4.2%)

220.6

(-2.2%)

58.5 59.2 59.2 61.6 58.1

Elevation

(ft

above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

222.00 1.72 1.85 1.29 1.25 1.31 32.6 34.2 35.3 35.5 35.8 1.77 1.95 1.36 1.27 1.34

222.50 2.11 2.21 1.67 1.65 1.72 33.6 35.7 37.4 37.3 37.6 2.21 2.36 1.77 1.69 1.76

223.00 2.38 2.57 2.05 2.05 2.11 36.8 37.0 39.3 39.1 39.3 2.49 2.76 2.18 2.10 2.18

223.50 2.45 2.87 2.23 2.22 2.29 44.2 39.3 44.7 44.9 45.0 2.57 3.09 2.37 2.29 2.36

224.00 2.71 2.82 2.58 2.59 2.65 47.5 48.2 46.8 46.7 47.3 2.87 3.02 2.75 2.69 2.74

224.50 3.08 3.21 2.92 2.93 2.99 48.7 49.0 48.9 49.0 49.5 3.29 3.47 3.12 3.05 3.10

225.00 3.44 3.56 3.26 3.25 3.33 50.2 50.2 50.6 51.2 51.5 3.69 3.87 3.51 3.41 3.47

225.50 3.73 3.84 3.57 3.57 3.59 52.4 52.7 52.8 53.5 54.8 4.02 4.18 3.85 3.57 3.74

225.78 3.86 3.97 3.69 3.51 3.80 54.3 54.1 54.7 58.7 55.4 4.15 4.35 4.00 3.68 3.98

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 29

Table 12. Summary of variability of cross-sectional characteristics in the Minebank Run study reach, 2005 through 2008.

Cross

section

Lateral

erosion

Cross-sectional

area

Channel

width

Mean channel

depth Comments

Aa Minimal Slight net increases at 

lower elevations and 

decreases at higher 

elevations; alternating increases and 

decreases over time 

at most elevations, 

but more variable in 

2005–06

Slight net increases and 

decreases at most 

elevations

Slight net increases and 

decreases at range of 

elevations; alternating 

increases and decreases 

over time, but more 

variable in 2005–06

Some minor vertical 

changes in section over 

time

Bb Minimal Net increase Slight net increases and 

decreases at most 

elevations

Net increase Considerable vertical 

changes with shifting of 

channel thalweg

Cc Some scour and 

fill along base 

of left terrace

Net increase at most 

elevations; alternating increases and 

decreases in 2005–07

Some net increases and 

decreases at different 

elevations

Net increase at low and 

high elevations; slight 

decrease at mid-range 

elevations; alternating 

increases and decreases 

in 2005–07

Considerable vertical 

changes in main channel 

with some lateral adjustment of left bank terrace

Dd Some scour and 

fill along base 

of left terrace

Net increase; alternating increases and 

decreases in 2005–08

Some net increases and 

decreases at different 

elevations

Net increase at most 

elevations; alternating 

increases and decreases 

in 2005–08

Considerable vertical 

changes in main channel; 

some lateral adjustment 

of left bank terrace and 

shifting of thalweg

Ee Some scour along 

base of right 

bank

Net increase at lower elevations; net decrease 

at higher elevations

Net decrease Net increase at most 

elevations; alternating 

increases and decreases 

in 2005–06

Considerable vertical 

changes and shifting of 

channel thalweg

Ff Some along right 

side of main 

channel

Net increase Slight net increases and 

decreases at most 

elevations

Net increase or same at 

most elevations; alternating decreases and 

increases in 2005–08

Considerable vertical 

changes; some lateral 

adjustment on right side 

of main channel

Gg Some along right 

bank in 2005; 

thalweg shift 

away from 

right bank during 2006–08

Net decrease; alternating increases and 

decreases in 2005–06

Slight net increases and 

decreases at most 

elevations

Net decrease; alternating 

increases and decreases 

in 2005–06

Considerable vertical 

changes and shifting of 

channel thalweg 

Hh Considerable on 

right side of 

channel

Net decrease; alternating increases and 

decreases in 2005–06

Slight net increase at 

most elevations

Net decrease; alternating 

increases and decreases 

in 2005–08

Considerable lateral and 

vertical changes in 

section, and shifting of 

channel thalweg

Ii Some along base 

of left bank at 

bottom of rock 

wall

Net decrease Slight net decrease at 

most elevations

Net decrease Considerable vertical 

changes and shifting of 

channel thalweg
30 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

with some overall aggradation on the left side of the section 

and the right overbank. Increasing elevations on the right 

overbank indicate that overbank flows may have deposited 

a 0.10–0.20-ft depth of fine sediment in the overbank area 

between 2005 and 2008. 

Cross section Ff showed net increases in cross-sectional 

area over time, along with mean depths that showed net 

increases or were approximately the same at different elevations over time. The channel thalweg was confined to the 

center of the main channel by a riprap rock wall that now 

composes the left bank in the section, but showed considerable 

variability in elevation over time. The net increases in crosssectional area and mean depth along with alternating increases 

and decreases between surveys indicates that sand and gravel 

could be temporarily stored in this location after certain storm 

events despite overall degradation during the post-restoration 

monitoring period. 

Cross section Gg showed a net decrease in cross-sectional 

area and mean depth over time. Some lateral erosion on the 

right bank was evident during the November 2005 survey, 

after which the thalweg began gradually shifting toward the 

center of the channel as the right side of the section aggraded 

over time. The decrease in cross-sectional area and mean 

depth, along with the shift in thalweg location over time, indicates an aggrading channel bed at cross section Gg with a net 

increase in storage of sediment that is transported during storm 

events (Doheny and others, 2007).

Cross section Ii showed net decreases in cross-sectional 

area and mean depth over time, along with a shift in the 

thalweg of the channel toward the left bank as the right side of 

the section aggraded over time. The net decreases in crosssectional area and mean depth, along with the shift in thalweg 

location over time, indicates an aggrading channel bed at cross 

section Ii with a net increase in storage of sediment that is 

transported during storm events (Doheny and others, 2007).

A summary of geomorphic conditions that were interpreted from changes in the cross sections during the postrestoration monitoring period is shown in figure 25. Cross 

sections Gg, Hh, and Ii, which represent approximately the 

upper 30 percent of the study reach, appear to be primary locations for sediment storage within the study reach. The increase 

in sediment storage in this area could be due to varying 

percentages of stormflow that now bypass the main channel by 

entering a small section of the pre-restoration stream channel 

about 250 ft upstream of cross section Ii, and then re-entering 

the main channel about 65 ft downstream of cross section 

Ii (Harrison and others, 2011). Cross sections Gg and Hh, 

which are in the only locations of the study reach that were 

not physically altered by the restoration work, indicate some 

lateral instability over time. This could be a result of realignment of the stream channel after it was physically moved in 

the area just upstream of these cross sections. Cross section 

Ff shows overall degradation of the channel bed with indications of temporary sediment storage and removal over time. 

Cross section Ee indicates a combination of aggradation and 

degradation of the channel bed as a result of the thalweg shift 

toward the base of the right bank over time. Cross sections Bb, 

Cc, and Dd indicate overall bed degradation with only minor 

or no lateral erosion. Cross sections Dd and Ee were the main 

locations in the study reach with evidence of sediment deposition on the flood plain due to stormflows that can overtop the 

right bank in these locations. Cross section Aa appears to be 

the most stable section in the study reach, with minor aggradation and degradation of the channel bed over time and little to 

no lateral erosion.

Based on analysis of the cross sections in both the preand post-restoration monitoring periods, lateral erosion has 

been considerably reduced due to elimination of nearly all 

cut banks in the study reach during the restoration. The cross 

sections showed little indication of any channel widening over 

time. Flood flows now have the ability to contact sections of 

the overbank area, and also bypass the main channel in small 

sections of the study reach, which was not possible in the 

pre-restoration monitoring period. Much of the geomorphic 

variability displayed in the post-restoration monitoring period 

is due to aggradation and degradation of the channel bed and 

shifting of the channel thalweg, instead of channel degradation 

and widening, and lateral erosion from receding cut banks, 

which was commonly observed during the pre-restoration 

monitoring period. Most locations in the study reach continue 

to show alternating patterns of sediment storage and removal 

over time. At least four of the cross sections indicated reduced 

variability in cross-sectional area and mean depth between 

surveys conducted from 2006 to 2008 (table 12), however. 

This indicates that the stream channel could be establishing 

a dynamic equilibrium and a more stable geometry after the 

initial geomorphic response observed in 2005 and 2006, just 

after the disturbances created by the restoration work. 

Hydraulic-Geometry Relations

Doheny and others (2006) defined hydraulic-geometry 

relations between discharge and hydraulic variables such as 

cross-sectional area, mean channel depth, channel width, and 

mean flow velocity to quantify changes in these variables to 

changes in discharge at Minebank Run during water years 

2002 through 2004. The relations presented were based on 

data from discharge measurements associated with the operation of USGS streamgage 0158397967, Minebank Run near 

Glen Arm, Maryland, and most were made just downstream 

from the streamgage during that time period. One hundred 

ten measurements were available for analysis in the prerestoration period, with discharges ranging from 0.04 ft3

/s to 

1,390 ft3/s. Ninety-six of those measurements were characterized as having discharges less than 10 ft3

/s. An additional 76 

measurements were made during the post-restoration monitoring period in water years 2005 through 2008, however, only 1 

of these measurements is characterized as having a discharge 

greater than 10 ft3/s . As data are not available in the postrestoration period to adequately describe hydraulic-geometry 

relations with discharges greater than 10 ft3/s, the analysis 
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 31

Figure 25. Summary of post-restoration geomorphic conditions in the Minebank Run study reach, 2005 through 2008.
32 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

presented below pertains only to relations that were developed 

based on measurements with discharges less than 10 ft3

/s.

Plots of hydraulic-geometry relations of cross-sectional 

area, channel width, mean channel depth, and mean velocity 

against discharge were developed (fig. 26). Most of the 

variables show moderate to strong linear relations with 

discharge. In the pre-restoration period, the strongest relation 

was between cross-sectional area and discharge, whereas in 

the post-restoration period, the strongest relation was between 

mean flow velocity and discharge. These relations indicate that 

channel depth in the vicinity of the streamgage was essentially 

unchanged by restoration activities, however, channel width 

increased, and as a result, the cross-sectional area increased. 

This increase in cross-sectional area caused a proportional 

decrease in mean flow velocity for comparable discharges. 

The trend of the relation between discharge and mean velocity 

indicates that the change in the relation likely does not extend 

far above discharges of 10 ft3

/s.

The relatively flat slope associated with the post-restoration relation between discharge and channel width is indicative 

of a rectangular channel cross section that has remained relatively stable in the general location of the streamgage during 

that period. It also explains the increase in slope of the relation 

between discharge and mean flow velocity from the pre- to 

post-restoration period. Because discharge is the product of 

cross-sectional area and mean flow velocity, as the magnitude 

of discharge has become less sensitive to channel width, and 

thus cross-sectional area, it has become more sensitive to 

mean flow velocity.

Grain-Size Distribution

Grain-size distributions were determined for sediment 

in the channel bed of the study reach between 2002 and 2008 

by use of pebble counts of the surficial channel bed sediments 

at each cross section (Wolman, 1954; Doheny and others, 

2007). The distributions were developed for each cross section 

based on the percentages of counted pebbles that fall within 

12 particle-size ranges of sand, gravel, cobbles, and boulders. 

Pre-restoration pebble counts were conducted in selected 

locations of the study reach in May 2002, and at all permanent 

cross section locations during May–June 2003. These data 

were previously published in Doheny and others (2007). Postrestoration pebble counts were conducted at all permanent 

cross section locations during May 2005, October 2006, and 

April 2008. Cumulative frequency distributions of percent 

finer were developed for the surficial bed material based on 

the pebble count data. The median particle diameter (d50), or 

particle diameter associated with 50 percent of the material 

being finer, was determined for the pebble counts at each cross 

section. Grain-size distributions from the pebble counts also 

were combined to develop composite analyses of the surficial 

bed material for the entire study reach for 2003, 2005, 2006, 

and 2008. The grain-size distributions from these years also 

were compared to the selected pebble counts from May 2002 

that were made at the three groundwater transect locations, 

corresponding to permanent cross sections Ee, Ff, and Gg, 

respectively (Doheny and others, 2007).

A wide range of grain sizes was present within the 

Minebank Run study reach in May–June 2003, prior to 

restoration of the stream channel. The majority of grain sizes 

fell between medium gravel (16 mm) and small cobbles (128 

mm). The d50 for the study reach at this time was approximately 20.5 mm, which falls within the range of coarse gravel. 

The analysis also indicated that over 24 percent of the pebbles 

counted throughout the study reach were sand (Doheny and 

others, 2007). More than half of the locations in the study 

reach had large percentages of sand, including cross sections 

Bb (30.0 percent); Ee (30.0 percent); Gg (25.0 percent); Hh 

(61.4 percent); and Ii (35.0 percent). Cross sections Gg, Hh, 

and Ii collectively represented approximately the upper 28 

percent of the study reach at that point in time. Cross sections 

Bb, Ee, and Ii were located near meanders in the stream channel, which indicated that finer material was being temporarily 

stored in these locations and transported during storm events. 

The cross-section geometry at cross section Bb also indicated 

a net aggradation of the channel bed during that period of 

time. Cross section Hh, which was in a fairly straight reach, 

was also a location where finer material could be stored 

because of a braided sand and gravel bar that was acting as a 

grade control at the start of the study.

Before restoration, cross sections Cc, Dd, and Ff had the 

coarsest distribution of grain sizes based on pebble counts 

conducted in May–June 2003, including a higher percentage 

of gravel and cobbles than the other locations. Cross section 

Aa had a considerable amount of gravel and some sand, but 

fewer cobbles. Cross sections Aa, Cc, and Ff were in fairly 

straight reaches, which indicated that finer material was being 

transported through these locations during storms with relatively small amounts of net storage. The cross-section geometry at cross sections Aa, Dd, and Ff also indicated lateral erosion of at least one of the channel banks prior to restoration, 

which may have exposed coarser bed material as the channel 

migrated. Only a few boulders were present in the entire study 

reach at that point in time (Doheny and others, 2007).

Pebble-count data that were collected during May 2005, 

October 2006, and April 2008 were used to develop grain-size 

distributions of percent finer for the surficial bed material in 

the study reach after restoration of the stream channel. The 

results are shown in tables 13–15. 

 There was considerable coarsening of the channel bed 

just after restoration of the stream channel (table 13). Most 

d50 values fall approximately within the range of coarse 

gravel (32 mm) to small cobbles (128 mm). Only cross section 

Hh indicates a large percentage of sand (35 percent) in May 

2005. Much of the channel bed coarsening can be attributed 

directly to larger bed material being placed in the channel bed 

during reconstruction of the stream channel. However, even 

cross sections Gg and Hh, which are located in areas that were 

not directly altered physically by restoration activities, showed 

considerable reductions in percentages of sand in 2005. Cross 
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 33

Figure 26. Comparison of pre- and post-restoration hydraulic-geometry relations of cross-sectional area, channel width, mean 

channel depth, and mean velocity against discharge using discharge measurements of less than 10 cubic feet per second at 

U.S. Geological Survey station 0158397967, Minebank Run near Glen Arm, Maryland.

sections Ee and Ii also showed considerable reductions in 

percentages of sand, but are not directly comparable between 

May–June 2003 and May 2005 due to physical relocation of 

the stream channel in these areas during the restoration. Cross 

section Bb showed the largest reduction in percentage of sand, 

with a reduction from 30 percent in May–June 2003 to 1 percent in May 2005.

A large increase in sand and gravel percentages in the 

study reach occurred between May 2005 and October 2006 

(table 14). Large storms in the watershed in October 2005 and 

June 2006 are the most likely cause of these increases. All 

cross sections showed increases in sand percentages except 

for cross section Hh, which showed a slight decrease from 

35 percent in May 2005 to 28 percent in October 2006. All 

cross sections showed increasing or nearly equivalent percentages of gravel in all class sizes. The locations with the 

largest increases in sand and gravel percentages between May 

2005 and October 2006 were at cross sections Dd, Ee, and Ii. 

Storage of fine material at these cross sections could be due 

to two rock weirs that were installed downstream of these 

locations during the restoration to establish grade control in 

selected areas of the stream channel.

Percentages of sand in April 2008 were elevated in comparison to those from May 2005, but considerably less than 

those found in October 2006 (table 15). Cross sections Dd, Ee, 

and Ii, which showed the largest increases in sand percentages 

in October 2006, all showed considerable decreases in April 

2008. The largest decrease was at cross section Dd, where the 

percentage of sand decreased from 46.0 percent to 2.0 percent 

between October 2006 and April 2008. Streamflow records 

from station 0158397967, Minebank Run near Glen Arm, 

Maryland, indicated only one large storm event in the watershed that occurred during this time period, in November 2006. 

This indicates that in the restored state, the stream channel is 

continuing to undergo alternating periods of sediment storage 

and erosion in different sections of the study reach. The lack 
34 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Table 13. Cumulative distribution of grain sizes, in percent finer, for surficial bed material at permanent cross section locations in the 

Minebank Run study reach, May 2005.

[Values represent the percentage of total particles that are finer than the particle size indicated in the particle size limit column of each row of values; 

mm, millimeters; %, percent]

Particle

description

Particle

size

limit

(mm)

Cross section

Aa

(%)

Bb

(%)

Cc

(%)

Dd

(%)

Ee

(%)

Ff

(%)

Gg

(%)

Hh

(%)

Ii

(%)

Silt 0.062 0 0 0 0 0 0 0 0 0

Sand 2 2.8 1.0 7.0 8.0 3.7 4.0 9.0 35.0 7.0

Very fine gravel 4 2.8 1.0 7.0 9.0 3.7 4.0 9.0 35.0 7.0

Fine gravel 8 2.8 3.0 13.0 11.0 4.7 7.9 16.0 45.0 10.0

Medium gravel 16 2.8 8.9 18.0 17.0 14.0 19.8 40.0 59.0 16.0

Coarse gravel 32 9.3 17.8 25.0 21.0 20.6 39.6 61.0 68.0 28.0

Very coarse gravel 64 35.5 48.5 51.0 51.0 51.4 65.3 82.0 88.0 47.0

Small cobbles 128 93.5 100.0 90.0 98.0 95.3 96.0 92.0 100.0 83.0

Large cobbles 256 98.1 100.0 100.0 100.0 100.0 100.0 100.0 100.0 98.0

Small boulders 512 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Medium boulders 1,024 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Large boulders 2,056 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Table 14. Cumulative distribution of grain sizes, in percent finer, for surficial bed material at permanent cross section locations in the 

Minebank Run study reach, October 2006.

[Values represent the percentage of total particles that are finer than the particle size indicated in the particle size limit column of each row of values; 

mm, millimeters; %, percent]

Particle

description

Particle

size

limit

(mm)

Cross section

Aa

(%)

Bb

(%)

Cc

(%)

Dd

(%)

Ee

(%)

Ff

(%)

Gg

(%)

Hh

(%)

Ii

(%)

Silt 0.062 0 0 0 0 0 0 0 0 0

Sand 2 10.0 18.0 14.0 46.0 56.0 16.0 14.0 28.0 56.0

Very fine gravel 4 10.0 28.0 19.0 54.0 69.0 24.0 26.0 37.0 71.0

Fine gravel 8 15.0 36.0 29.0 58.0 79.0 32.0 42.0 44.0 74.0

Medium gravel 16 25.0 43.0 35.0 61.0 87.0 43.0 57.0 65.0 78.0

Coarse gravel 32 33.0 62.0 54.0 70.0 91.0 52.0 73.0 80.0 87.0

Very coarse gravel 64 62.0 78.0 72.0 79.0 96.0 79.0 87.0 97.0 94.0

Small cobbles 128 88.0 94.0 92.0 95.0 98.0 98.0 99.0 100.0 99.0

Large cobbles 256 98.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Small boulders 512 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Medium boulders 1,024 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Large boulders 2,056 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 35

Table 15. Cumulative distribution of grain sizes, in percent finer, for surficial bed material at permanent cross section locations in the 

Minebank Run study reach, April 2008.

[Values represent the percentage of total particles that are finer than the particle size indicated in the particle size limit column of each row of values; 

mm, millimeters; %, percent]

Particle

description

Particle

size

limit

(mm)

Cross section

Aa

(%)

Bb

(%)

Cc

(%)

Dd

(%)

Ee

(%)

Ff

(%)

Gg

(%)

Hh

(%)

Ii

(%)

Silt 0.062 0 0 0 0 0 0 0 0 0

Sand 2 11.0 7.0 11.0 2.0 38.0 17.0 7.0 23.0 22.0

Very fine gravel 4 20.0 20.0 18.0 5.0 43.0 38.0 22.0 36.0 39.0

Fine gravel 8 30.0 32.0 29.0 13.0 53.0 51.0 39.0 49.0 52.0

Medium gravel 16 50.0 53.0 48.0 30.0 67.0 67.0 60.0 68.0 64.0

Coarse gravel 32 70.0 70.0 67.0 61.0 79.0 77.0 77.0 83.0 72.0

Very coarse gravel 64 86.0 88.0 83.0 85.0 89.0 86.0 95.0 93.0 84.0

Small cobbles 128 99.0 98.0 96.0 98.0 99.0 96.0 99.0 98.0 97.0

Large cobbles 256 99.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Small boulders 512 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Medium boulders 1,024 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Large boulders 2,056 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

of large storm events between October 2006 and April 2008 

indicates that smaller, less extreme storm events could be 

playing an enhanced role in transporting sand through the 

study reach over time.

Median particle diameters for all pebble counts conducted in the study reach between 2002 and 2008 were determined (Doheny and others, 2007). The results are presented in 

table 16.

A slight coarsening of the channel bed prior to restoration is evident at the three groundwater transect locations, 

which correspond to permanent cross sections Ee, Ff, and Gg 

(Doheny and others, 2007) (table 16). In 2005, the channel bed 

was considerably coarser in all cross sections than in 2003 just 

after the restoration work was completed. In 2006, the channel 

bed was considerably finer in all cross sections approximately 

1.5 years after the restoration work was completed. Except for 

cross section Ee, which was physically moved within the valley during the restoration, the d50 values from 2006 are very 

similar to those found in equivalent locations in 2002, prior to 

restoration. 

In 2008, all cross sections in the study reach were 

considerably finer than in 2005, just after the restoration 

work was completed. Different sections of the study reach, 

however, varied in becoming finer or coarser between 2006 

and 2008. For example, the lowermost section of the study 

reach at cross sections Aa, Bb, and Cc showed continued 

fining between 2006 and 2008 whereas cross sections Dd and 

Ee became coarser again. Cross sections Ff became finer but 

cross sections Gg and Hh remained almost the same between 

2006 and 2008. Cross section Ii became coarser between 2006 

and 2008. This indicates that the stream channel underwent an 

adjustment period after restoration where the channel bed was 

becoming finer throughout the study reach between 2005 and 

2006. Between 2006 and 2008, different sections of the study 

reach were alternating between continued fining and coarsening after the initial post-restoration adjustment period.

Data from the pebble counts at each of the nine cross 

sections also were combined to develop composite grain-size 

distributions of the surficial bed material for the entire study 

reach over time. Each distribution was developed using over 

900 pebbles that were collected in the nine cross sections during May–June 2003, May 2005, October 2006, and April 2008 

(Doheny and others, 2007). The grain-size distributions and 

computations of percent finer for the composite pebble counts 

in the Minebank Run study reach are shown in table 17. These 

results are shown graphically in figure 27.
36 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Table 16. Median particle diameter from pebble counts associated with each permanent cross 

section in the Minebank Run study reach, 2002 through 2008.

[d50, median particle diameter; mm, millimeters; ---, not applicable; <, less than]

Cross

section

d50 

(mm)

2002 2003 2005 2006 2008

Aa --- 20.5 75.0 50.0 16.0

Bb --- 9.0 65.0 21.0 15.0

Cc --- 50.0 63.0 30.0 17.0

Dd --- 36.0 63.0 3.0 24.0

Ee1 18.0 30.0 62.0 <2.0 6.5

Ff 31.5 36.0 42.0 30.0 7.5

Gg 10.0 14.0 22.0 11.0 11.0

Hh --- <2.0 10.5 10.0 9.0

Ii1 --- 10.2 70.0 <2.0 7.0

1

 Stream channel was physically moved during the restoration.

Table 17. Grain-size distributions and computation of percent finer from composite pebble counts at all permanent cross sections, 

Minebank Run study reach, 2003 through 2008.

[mm, millimeters; %, percent]

Particle

description

Particle

size limit

(mm)

Cumulative percent finer

(%)

May/June 2003 May 2005 October 2006 April 2008

Silt 0.062 0 0 0 0

Sand 2 24.2 8.5 28.7 15.3

Very fine gravel 4 25.1 8.6 37.6 26.8

Fine gravel 8 30.4 12.4 45.4 38.7

Medium gravel 16 44.4 21.5 54.9 56.3

Coarse gravel 32 58.5 32.0 66.9 72.9

Very coarse gravel 64 80.5 57.5 82.7 87.7

Small cobbles 128 95.7 94.2 95.9 97.7

Large cobbles 256 99.9 99.6 99.8 99.9

Small boulders 512 99.9 100.0 100.0 100.0

Medium boulders 1,024 99.9 100.0 100.0 100.0

Large boulders 2,048 100.0 100.0 100.0 100.0
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 37

The data in table 17 show that the majority of particle 

sizes in the Minebank Run study reach fell between fine 

gravel and small cobbles for all composite pebble counts both 

before and after restoration of the stream channel. The analysis 

also indicates considerable variability in the percentages of 

sand in the study reach over time. Restoration of the stream 

channel produced a much coarser channel bed because of large 

gravel and small cobbles that were placed on the bed. This 

is shown by the reduction in sand percentages in May 2005. 

The percentages of sand in October 2006 and April 2008 were 

elevated in comparison to May 2005, but alternated in relative 

magnitude over time as the stream channel began its natural 

response to the restoration. The increase in sand percentages 

in October 2006 and considerable decrease in April 2008 are 

indicative of alternating periods of storage and transport of 

fine bed material in the study reach over time.

From figure 27, the d50 for the study reach ranged from 

20.5 mm (coarse gravel) in May–June 2003 to 53 mm (very 

coarse gravel) just after restoration of the stream channel 

in May 2005. The d50 for the study reach was found to be 

11 mm in October 2006 and 13 mm in April 2008, which falls 

within the range of medium gravel. This analysis indicates 

that despite restoration of the stream channel, sources of fine 

sediment still exist in the watershed. The abundance of relatively small bed material sizes in combination with the flashy 

streamflow from urban and suburban runoff likely contributes 

to the considerable changes in grain-size distributions that 

have been observed over time (Doheny and others, 2006; 

Doheny and others, 2007).

The grain-size distributions that were developed from 

pebble count data collected in May 2002 and May–June 

2003 were compared to distributions from pebble count data 

collected in May 2005, October 2006, and April 2008 at 

the three groundwater transect locations, which correspond 

to permanent cross sections Ee, Ff, and Gg, respectively. 

Grain-size distributions at these locations for 2002 through 

2008 are shown in figures 28–30. An overall shift to larger 

grain-size distributions, or coarsening, can be seen at all 

three locations between May 2002 and May–June 2003 that 

was largely due to changes in percentages and distribution of 

gravel on the surface of the channel bed (Doheny and others, 

2007). Considerable coarsening of the channel bed also is 

evident at all three cross sections in April 2005 as a result of 

the restoration work. In October 2006, all three cross sections 

showed considerable fining of the bed material throughout 

nearly the full range of particle sizes. In April 2008, cross 

section Ee indicated coarsening again, whereas cross section 

Ff indicated continued fining. In April 2008, cross section Gg 

indicated a combination of coarsening of particle sizes less 

than 10 mm, and continued fining of particle sizes greater than 

10 mm, which resulted in an equivalent d50 of 11 mm for both 

October 2006 and April 2008. These results further support 

the conclusion that different sections of the study reach began 

alternating between continued fining and coarsening after an 

initial post-restoration adjustment period of considerable fining of the channel bed.

Net Changes in Channel Bed Elevation

Net changes in channel bed elevation were monitored 

in selected locations of the study reach by use of stream 

piezometers that had been installed for monitoring shallow 

groundwater under the channel bed. The locations of these 

piezometers correspond closely to the locations of cross sections Ee, Ff, and Gg (Doheny and others, 2006; Doheny and 

others, 2007). Bed elevations were determined by measuring 

the distance between the top of the piezometer and the channel bed, and subtracting the distance to the channel bed from 

the known elevation of the measuring point at the top of the 

piezometer that had been previously surveyed for purposes of 

monitoring groundwater levels. Bed elevations were initially 

tracked between December 2002 and July 2004, prior to the 

stream channel being restored, and again between September 

2005 and October 2008, after the stream channel was restored. 

Graphs indicating the net changes in bed elevation during the 

pre- and post-restoration periods at these three locations are 

shown in figures 31–33.

Cross Section Ee

During the pre-restoration phase of the monitoring that 

occurred between January 2003 and July 2004, rapid aggradation and degradation of the channel bed at cross section Ee 

was evident (Doheny and others, 2007). Analysis of pre-restoration data indicated that volumes of sediment were gradually 

being stored in this section of the stream channel, and then 

rapidly transported downstream by flows from large storm 

events.

When the stream channel was restored during 2004 and 

early 2005, the channel in this reach was moved approximately 70 ft from its original location and realigned with a 

reduced sinuosity. The original stream channel became an 

oxbow that was cut off from the restored stream channel, but 

acted as a catchment for storm runoff from the north side of 

the stream valley.

The restored stream channel had an initial bed elevation 

in September 2005 that was approximately 2.5 ft higher than 

the last measured bed elevation prior to restoration in July 

2004 (fig. 31). The measured bed elevations varied by approximately 0.40 ft between September 2005 and June 2006, when 

a large storm event increased the bed elevation by over 0.70 

ft. Between June 2006 and September 2008, the bed elevation 

varied within an approximate range of 0.25 ft, with some alternating periods of aggradation and degradation over time.

 The data indicate that in this location, the restored 

stream channel eventually reached a point of dynamic equilibrium after some vertical adjustments during the initial 

post-construction period between September 2005 and June 

2006. However, the vertical adjustments in bed elevation were 

considerably less than those that were evident during the prerestoration phase of the monitoring, when the data indicated 

that the stream channel was undergoing alternating periods of 

extreme sediment storage and erosion at this location (Doheny 

and others, 2007).
38 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Figure 27. Comparison of composite pebble counts for 

Minebank Run study reach above Sherwood Bridge before and 

after channel restoration, 2003 through 2008.

Figure 29. Comparison of particle-size distributions at cross 

section Ff, 2002 through 2008.

Figure 28. Comparison of particle-size distributions at cross 

section Ee, 2002 through 2008.

Figure 30. Comparison of particle-size distributions at cross 

section Gg, 2002 through 2008.
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 39

Figure 31. Net changes in bed elevation over time at cross section Ee, January 2, 2003 through October 7, 2008.

Figure 32. Net changes in bed elevation over time at cross section Ff, December 3, 2002 through October 7, 2008.

Figure 33. Net changes in bed elevation over time at cross section Gg, January 2, 2003 through September 15, 2008.
40 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Cross Section Ff

During the pre-restoration phase of the monitoring that 

occurred between December 2002 and July 2004, alternating 

periods of aggradation and degradation of the channel bed 

were observed at cross section Ff (Doheny and others, 2007). 

The range of measured bed elevations was only 0.62 ft, which 

was considerably less than that observed at cross section Ee 

during the pre-restoration phase of the monitoring. 

When the stream channel was restored during 2004 and 

early 2005, the channel in this reach was armored with riprap 

along the left bank to prevent lateral erosion in the vicinity of 

a sanitary sewer pipe that parallels the stream in this location. 

In addition, woody vegetation was planted along the right 

bank to provide more natural erosion protection. Also, a rock 

vein structure was installed in the stream channel a short 

distance downstream of the cross section, which created a 

new control point in this location. The alignment of the stream 

channel was not altered much in this location, but the ability of 

the channel to adjust itself laterally was reduced considerably. 

As with cross section Ee, measurements of bed elevation 

at cross section Ff indicated some considerable vertical adjustment between September 2005 and July 2006 (fig. 32). During 

this period, the maximum range of bed elevations measured 

at cross section Ff was 0.72 ft. Between January 2007 and 

June 2008, the measurements also indicate a lengthy period 

of net aggradation where the bed elevation increased by about 

0.67 feet. This was followed by a fairly rapid decrease in the 

bed elevation of 0.61 ft during July and August of 2008, and 

the beginning of a new cycle of aggradation that began in 

September 2008, when the bed elevation increased by 0.26 ft.

Overall, the post-restoration data indicated an alternating 

pattern of sediment storage with some instances of fairly rapid 

erosion over time. This was similar to the pattern observed 

during the pre-restoration monitoring period, but with larger 

extremes and more rapid changes in erosion over time. The 

reduction of lateral erosion in the reach caused by the introduction of the riprap and woody vegetation along the banks 

could be causing additional erosive energy to be directed 

toward the channel bed, resulting in more extremes and rapid 

erosion. The data also indicate that this reach has the ability 

to store larger volumes of sediment for longer periods of time 

than in its pre-restoration state, possibly due to the grade 

control introduced downstream of the section when the rock 

vein was constructed. Overall, the channel bed showed slight 

degradation during the post-restoration period, with a bed 

elevation that was generally higher than in the pre-restoration 

phase of the monitoring that was completed in July 2004.

Cross Section Gg

Relatively small changes in bed elevation were observed 

at cross section Gg during the majority of the pre-restoration 

monitoring period between January 2003 and July 2004 

(Doheny and others, 2007). The analysis indicated some 

pulsing of sediment through the cross section, but with 

considerably smaller amounts of sediment storage in this location than at either cross section Ee or Ff (Doheny and others, 

2007). The measurements of bed elevation also indicated some 

increased degradation and instability of the channel bed during 

the final 3 months of the pre-restoration monitoring period 

between May and July 2004 (Doheny and others, 2007).

When the stream channel was restored during 2004 and 

early 2005, this section of the channel was not physically 

disturbed by the construction work. All geomorphic changes 

observed in this cross section were most likely due to restoration activities and features that were implemented in the 

upstream or downstream vicinity of this reach. 

After the restoration work was completed and geomorphic monitoring resumed in the study reach in September 

2005, the bed elevation in this cross section was about 0.30 ft 

lower than the last measured bed elevation prior to restoration 

(fig. 33). The bed elevation varied within a range of 0.66 ft 

between September 2005 and December 2006, with the most 

rapid changes occurring during storm events in October 2005 

and June 2006. Between December 2006 and June 2008, the 

bed elevation varied within a range of 0.21 ft, with some alternating periods of slight aggradation and degradation over time.

The data indicate that at cross section Gg, the stream 

channel eventually reached a point of dynamic equilibrium 

during the post-restoration period, but after a period of considerable vertical adjustment in bed elevation between September 

2005 and December 2006. The data also indicate that this 

reach continues to store lesser amounts of sediment over time 

than either cross section Ee or Ff. Overall, the channel bed 

aggraded during the period of post-restoration monitoring, 

but with bed elevations that were generally lower than in the 

pre-restoration phase of the monitoring that was completed in 

July 2004.

Study Reach Summary

Overall, the post-restoration data on measured bed elevations indicate that cross section Ee, which was one of the most 

geomorphically unstable locations in the study reach prior to 

restoration, is less prone to the rapid and extreme changes in 

bed elevation that were observed prior to restoration. Possible 

causes for this include: (1) the reduction in channel sinuosity 

and realignment of the stream channel in this area, (2) the 

reconstruction of the channel banks that allows runoff from 

storms to spill out of the stream channel and onto the flood 

plain in this reach, and (3) the oxbow that was created from 

the old channel that now acts as a catchment for some of the 

storm runoff in this location. 

The data also indicate that cross section Ff is more prone 

to lengthy periods of sediment storage with rapid removal 

of stored sediment, possibly due to the restoration features 

that were implemented in the vicinity of this cross section to 

place more control on the horizontal and vertical adjustments 

of the stream channel. As in the pre-restoration phase of the 

monitoring, the data from cross section Gg indicate periods of 

relative stability of the channel bed, but also a few periods of 
Comparison of Pre- and Post-Restoration Geomorphic Characteristics 41

rapid vertical changes in bed elevation, and relatively smaller 

amounts of net storage of sediment than at cross sections Ee 

and Ff. All three cross sections appear to have undergone a 

period of considerable vertical adjustment for approximately 

9 to 15 months after the stream restoration was completed and 

monitoring was resumed.

Shear Stress Analysis

Boundary shear stress is the force that flowing water 

imposes on the channel bed and banks, which is the natural 

boundary of a stream channel. This quantity was first defined 

by Shields (1936), and was computed for peak discharges 

associated with 21 storms during the pre-restoration period 

(November 2001 through September 2004) by Doheny 

and others (2007). The reach used for these computations 

included a longitudinal distance of approximately 180 ft, from 

the location of the continuous-record streamgage (station 

0158397967) to station 0158397968, located just upstream of 

cross section Gg. The results of those computations indicated 

that most of these pre-restoration events were characterized 

by both boundary shear stresses and mean peak-discharge 

velocities that were larger than those noted by Rosgen (1996) 

for various non-urban stream types. The slope of the best-fit 

line between the boundary shear stress and mean velocity at 

peak discharge for these 21 storms discharges at Minebank 

Run was flatter than the slopes defined by Rosgen (1996) for 

all defined non-urban stream types. The physical interpretation 

of these facts was that small changes in mean flow velocity in 

Minebank Run resulted in relatively large changes in boundary 

shear stress, and correspondingly rapid increases in the force 

applied to the stream-channel boundaries with an associated 

increase in the stream’s ability to transport sediment.

After restoration construction and activities had moved 

downstream from cross section Gg in November 2004, 11 

storm discharges occurred for which the necessary crosssection geometry and water-surface slope data were available 

to compute boundary shear stress. The boundary shear stresses 

at peak discharge for these 11 events were computed. Data 

variables and associated boundary shear stress values for 

the 11 post-restoration storm events are shown in table 18. 

Boundary shear stress also was plotted against the mean velocity at peak discharge for these 11 storm events and compared 

to pre-restoration conditions (fig. 34). As shown in figure 34, 

the magnitudes of the boundary shear stresses for post-restoration events are comparable to those from the pre-restoration 

period, however, the mean flow velocities at peak discharge 

are somewhat smaller than those during the pre-restoration 

period. Also, the slope of the best-fit line showing the relation 

between boundary shear stress and mean velocity is nearly 50 

percent greater than that for the pre-restoration period. This 

indicates that a larger increase in mean velocity is required to 

apply a given increase in force on the channel bed and bank 

materials and, in turn, for initiation of sediment transport. The 

R2

 of 0.64 indicates that the strength of the relation is lower in 

the post-restoration period. This may be caused by the channel adjustments that were occurring, particularly in the early 

stages, after restoration work was completed.

As was previously discussed, the magnitude, intensity, 

and distribution of the precipitation events in the pre- and 

post-restoration periods are generally comparable. Therefore, 

it is reasonable to conclude that the change in the relation 

noted above is a result of changes introduced to the stream 

channel by the restoration work. Specifically, it is reasonable 

to conclude that the stabilization (bed-elevation control points) 

and realignment of the channel, including the oxbow cutoffs 

designed to increase channel conveyance at peak flows, have 

acted in conjunction to decrease peak-flow velocities.

Net Changes in Sediment Volume

Net changes in sediment volume that was stored in or 

removed from the study reach between cross-sectional surveys 

were estimated during both the pre- and post-restoration 

monitoring periods. Differences in cross-sectional area at 

each of the nine permanent cross sections were determined at 

channel-full elevation between each successive survey. A net 

increase in cross-sectional area was interpreted as degradation in the cross section. A net decrease in cross-sectional area 

was interpreted as aggradation in the cross section. The stream 

length between each cross section was used to compute a difference in volume for each cross section by (1) applying half 

the stream length to the upstream cross section and half to the 

downstream cross section, and (2) multiplying the difference 

in cross-sectional area at each cross section between surveys 

by the appropriate stream length to determine changes in volume in cubic feet for each reach segment associated with each 

of the cross sections. The changes in volume between crosssectional surveys for reach segments associated with each 

permanent cross section in the Minebank Run study reach are 

presented in table 19.

Degradation in the study reach was evident during the 

pre-restoration phase of the monitoring, with considerably 

greater degradation during the period between December 2002 

and July 2003 (table 19). The period between February 2004 

and April 2005 was not included in the investigation because 

any changes occurring during that period were most likely due 

to physical reconstruction of the stream channel that occurred 

between June 2004 and February 2005, and not natural aggradation or degradation caused by natural geomorphic processes. 

The period between April 2005 and December 2005 indicated 

degradation in the study reach that was most likely due to 

initial geomorphic adjustment of the stream channel after 

completion of the restoration work in early 2005. Between 

December 2005 and August 2007, the results indicate overall 

aggradation within the study reach. Between August 2007 

and April 2008, the results indicate overall degradation in the 

study reach.

To estimate the volume of sediment associated with 

the changes in volume between cross-sectional surveys that 
42 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Table 18. Data variables and boundary shear stress computations for 11 storm runoff events in the Minebank Run study reach, 

December 2004 through August 2008.

[ft3/s, cubic feet per second; ft2, square feet; ft/s, feet per second; ft, feet; ft/ft, feet per foot; lb/ft2, pound per square foot]

Date of storm 

event

Peak discharge 

(ft3

/s)

Cross-sectional 

area 

(ft2

)

Mean velocity 

(ft/s)

Hydraulic radius

(ft)

Water-surface 

slope 

(ft/ft)

Boundary shear 

stress 

(lb/ft2)

12/23/2004 304 101.7 2.99 2.23 0.0072 1.00

1/14/2005 224 80.3 2.79 2.23 0.0065 0.90

3/28/2005 227 81.0 2.80 2.24 0.0066 0.92

7/8/2005 231 82.1 2.81 2.26 0.0067 0.94

10/8/2005 883 182.1 4.85 3.40 0.0094 2.00

6/3/2006 770 171.8 4.48 3.24 0.0082 1.66

6/25/2006 1,400 204.1 6.86 3.58 0.0095 2.12

7/6/2006 370 109.6 3.38 2.29 0.0119 1.70

11/16/2006 527 126.1 4.18 2.60 0.0069 1.12

7/10/2007 237 72.0 3.29 1.97 0.0074 0.91

8/13/2008 1,100 184.5 5.96 3.41 0.0067 1.41

Figure 34. Boundary shear stress versus mean velocity at 

the peak discharge during storm events in the Minebank Run 

study reach, November 2001 through September 2004, and 

December 2004 through August 2008.

were presented in table 19, the porosity of the sediment in 

the stream channel must be considered. Typical porosities of 

gravel-bed streams and rivers range from 21 to 34 percent 

(Haschenburger and Roest, 2008). Applying this range of 

porosity to the computed changes in volume for the study 

reach between cross-sectional surveys allowed the volume 

of pore space to be computed and subtracted out, with the 

remainder being the volume of sediment removed or stored 

in the reach. To estimate a rate of change in sediment volume 

over time, the average number of days between cross-sectional 

surveys was determined, and a bulk density for natural gravel 

with sand of 120 lb/ft3

 (pounds per cubic foot) was used 

to convert the sediment volume estimates to a rate that is 

presented in tons per year. Estimates of sediment volume and 

the rate of change in sediment volume stored or removed from 

the Minebank Run study reach between December 2002 and 

April 2008 are presented in table 20. 

Sediment was removed from the study reach prior to 

restoration with the largest sediment volume and rate of 

removal occurring during the period of December 2002 to 

July 2003 (table 20). The storm and flood of June 12, 2003, 

which produced a peak discharge of 1,390 ft3

/s and is the 

second largest peak for the period of record at the continuousrecord streamgage, is a likely factor in the volume of sediment removed from the study reach during this period. During 

the post-restoration period, the data in table 20 indicate an 

alternating pattern of sediment removal and storage, with 

the largest sediment volume and rate of removal occurring 

between April 2005 and December 2005. This period was just 

after completion of the restoration work and the stream channel was likely in the early stages of geomorphic adjustment 

and response to the physical disturbances that were applied 

during the restoration. The largest volumes and rates of sediment storage occurred during December 2005 to September 

2006. The storm and flood of June 25, 2006, which produced 

a peak discharge of 1,400 ft3

/s and is the peak of record at the 

continuous-record streamgage, is a likely factor in the volume 

of sediment stored in the study reach during this period. The 

computations for September 2006 to August 2007 indicate 

additional storage of sediment, but at a considerably reduced 

volume and rate than the previous period. From August 2007 

to April 2008, the computations indicate overall removal of 

sediment from the study reach, but with volumes and rates that 

were reduced from the initial period of geomorphic adjustment 

and response to the restoration work between April 2005 and 

December 2005.
Comparison of 1960s Bed Elevations and Longitudinal Profile to 2002–08 Study Reach Conditions 43

Table 19. Changes in volume, in cubic feet, between cross-sectional surveys for reach segments associated with each permanent 

cross section, Minebank Run study reach, December 2002 through April 2008.

[-, degradation in reach segment; +, aggradation in reach segment; ft, feet] 

Cross section December 2002 – 

July 2003

July 2003 – 

February 2004

April 2005 – 

December 2005

December 2005 –

September 2006

September 2006 –

August 2007

August 2007 – 

April 2008

Aa -210.9 -684.5 +225.0 -213.0 -78.0 +81.0

Bb +2,236.3 -10.7 -1,228.8 +297.6 +1,056.0 -1,440.0

Cc -1,580.8 +53.2 -411.0 -301.4 +150.7 +465.8

Dd -1,302.4 -1,742.4 -915.0 +525.0 +210.0 -645.0

Ee -1,824.5 +2,603.5 +888.8 +464.6 +80.8 -101.0

Ff -2,325.0 -148.8 -316.8 -1,029.6 +693.0 -1,089.0

Gg -1,700.4 -249.6 -1,643.0 +3,131.0 -31.0 -403.0

Hh -1,391.2 +131.6 -1,823.6 +3,120.8 +470.0 -827.2

Ii -1,242.0 -2,192.4 +432.0 +378.0 -10.8 +32.4

TOTAL -9,340.9 -2,240.1 -4,792.4 +6,373.0 +2,540.7 -3,926.0

Note: Total reach length was 1,315 ft between December 2002 and February 2004, and 1,264 ft between April 2005 and April 2008.

Table 20. Estimates of sediment volume and rate of change in sediment volume stored or removed from the Minebank Run study 

reach, December 2002 through April 2008.

[n, porosity; %, percent; -, sediment volume removed from study reach; +, sediment volume stored in study reach; ft3, cubic feet; ft, feet]

Time period between 

cross-sectional surveys

Minimum 

sediment 

volume

(ft3

)

(n = 34%)

Mean

sediment 

volume

(ft3

)

(n = 27.5%)

Maximum 

sediment 

volume

(ft3

)

(n = 21%)

Average 

number

of days 

between 

surveys

Rate of change in sediment 

volume stored or removed 

from study reach 

(tons/year)

December 2002–July 2003 -6,165.0 -6,772.2 -7,379.3 214 -631.0 to -956.0

July 2003–February 2004 -1,478.5 -1,624.3 -1,770.0 205 -158.0 to -189.1

April 2005–December 2005 -3,163.0 -3,474.5 -3,786.0 232 -298.6 to -357.4

December 2005–September 2006 +4,206.0 +4,620.5 +5,035.0 293 +314.4 to +376.3

September 2006–August 2007 +1,677.0 +1,842.0 +2,007.0 342 +106.8 to +128.5

August 2007–April 2008 -2,591.0 -2,846.5 -3,102.0 219 -259.1 to -310.2

Note: Total reach length was 1,315 ft between December 2002 and February 2004, and 1,264 ft between April 2005 and April 2008.

Comparison of 1960s Bed Elevations 

and Longitudinal Profile to 2002–08 

Study Reach Conditions

A generalized channel bed profile of the Minebank Run 

study reach from the early 1960s was located within a set of 

engineering plans that was prepared in 1966 for the design of a 

sanitary sewer line that was installed along the Minebank Run 

stream channel and flood plain (Matz, Childs, and Associates, 

Inc., 1966). Analysis of the bed profile from the plans indicated that the slope of the channel bed in the early 1960s was 

0.0101, or about 1 percent. This slope was exactly the same 

as the slope based on the surveyed longitudinal profile from 

2002, and slightly greater than the slope found in subsequent 

surveys between 2003 and 2008 (table 9).

From the plans, the top of the sewer pipe was designed 

to be a minimum of 1.5 ft and a maximum of 4.1 ft below the 

elevation of the channel bed in the study reach. On average, 

there was approximately 2.5 ft between the channel bed 

elevation and the top of the sewer pipe (Matz, Childs, and 

Associates, Inc., 1966). Longitudinal surveys of the same 

reach that were conducted between 2002 and 2004 indicated 

exposure of the pipe in some sections of the channel, and 

channel bed elevations that ranged from 0.7 ft to nearly 3.1 

ft below the top of the sewer pipe. This indicates that over 

approximately 40 years between the early 1960s and 2002, the 

channel bed may have degraded by approximately 3.2 ft, and 
44 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

by as much as 5.6 ft in some locations, possibly due to local 

scour in the vicinity of the sewer pipe.

The generalized channel bed profile from the early 1960s 

was plotted for the study reach area and compared to channel 

bed elevations that were surveyed in 2002 during the prerestoration period (fig. 35). Generalized channel bed profiles 

from surveys conducted just after restoration in 2005 and 3 

years after restoration in 2008 are also presented for comparison (fig. 36). All profiles indicated consistently lower channel 

bed elevations in 2002, 2005, and 2008 than in the early 

1960s. Bed degradation from land-use change in the watershed 

is the likely cause of the differences observed between the 

early 1960s and 2002. Differences throughout the study reach 

ranged from 1.3 ft to 5.0 ft based on comparison of elevations 

at approximately equivalent locations along the profile. The 

2005 profile indicates that the channel bed was elevated in 

most sections of the study reach after restoration, but lower 

between stations 3,600 ft and 3,850 ft, which includes the area 

at the continuous-record streamgage and well transect 3 (figs. 

14, 35, 36). This area of the stream channel was not physically 

altered by the restoration work and appears to have responded 

naturally. Bed elevations in the study reach ranged from 0.8 ft 

to 4.8 ft lower in 2005 than the early 1960s bed elevations at 

approximately equivalent locations along the channel profile. 

The 2008 profile quantifies the natural adjustments to the 

stream channel that occurred after restoration, which included 

alternating areas of elevated and lower bed elevations when 

compared to the newly restored profile from 2005. In 2008, 

bed elevations ranged from 0.8 ft to 4.1 ft lower than the early 

1960s bed elevations at approximately equivalent locations 

along the channel profile.

By scaling distances using the early 1960s channel bed 

profile, it was determined that the channel bed elevation at 

cross section Hh (station 3678.0) was approximately 223.2 ft 

NGVD at that point in time. The thalweg elevations that were 

surveyed between 2002 and 2008 at cross section Hh, and the 

differences in elevation from those found in the early 1960s 

are shown in table 21.

The thalweg elevation at cross section Hh is consistently 

lower than it was in the early 1960s (table 21). With the exception of November 2005, the difference between the surveyed 

bed elevations and that determined from the early 1960s 

profile ranged from 3.2 to 3.8 ft. The variability in the elevation found in November 2005 could be due to adjustments that 

the stream channel was undergoing immediately after completion of the restoration work. The range of 3.2 to 3.8 ft above 

the thalweg elevation at cross section Hh is fairly consistent 

with the elevation of a terrace adjacent to the right bank of the 

channel. This indicates that the channel bed may have been 

at the elevation of this terrace in the early 1960s, and over 

approximately 40 years, the bed has degraded by about 3.2 to 

3.8 ft. If this feature is, in fact, evidence of the channel bed 

elevation at that point in time, it is possible that the cross-sectional area of the stream channel prior to the degradation was 

approximately 150 square feet, and that the cross-sectional 

area may have increased by as much as 40 to 60 percent in 

some locations of the study reach.

Bed elevations also were compared in several other locations to determine relative differences in elevation between 

the early 1960s and the present. For example, the bed elevation at station 4,944 ft, which is the lowermost station of the 

study reach near Sherwood Bridge, was found to be about 4.2 

ft lower in 2002 than in the early 1960s, about 3.6 ft lower in 

2005, and about 3.1 ft lower in 2008. The differences between 

2002, 2005, and 2008 are likely due to the stream restoration, 

coupled with the net effects of natural post-restoration adjustments to the channel bed from stormflows.

A comparison of bed elevations at the confluence of 

Minebank Run and Harts Run was possible based on the 2005 

longitudinal profile survey and bed elevations from the early 

1960s profile. This indicated that the channel bed was about 

3.2 ft lower in 2005 than in the early 1960s. Because the prerestoration longitudinal profile surveys were not extended up 

to the confluence with Harts Run, a direct pre-restoration comparison at this point was not possible. However, based on the 

early 1960s profile and the 2002 longitudinal profile survey, a 

comparison of the most upstream point from the 2002 survey 

was possible. This point was approximately 255 ft downstream 

of the confluence between Minebank Run and Harts Run, and 

indicated that the channel bed was approximately 3.0 ft lower 

in 2002 than in the early 1960s.

While the stream channel has maintained an overall slope 

of about 1 percent, all comparisons of bed elevations made 

between the early 1960s and 2002 indicate that the channel 

bed degraded over time in the Minebank Run study reach 

within an approximate range of 1.3 ft to 5.0 ft, with possible 

local scour of up to 5.6 ft in locations near the sanitary sewer 

pipe. In the post-restoration condition, evidence indicates that 

the channel bed is still about 0.8 ft to 4.8 ft lower than bed 

elevations from the early 1960s at approximately equivalent 

locations along the profile. 

Data Limitations

The geomorphic data collected during this study are 

representative of approximately 6 years in the long-term geomorphic evolution of the stream channel. Data collection over 

longer periods of time could provide a longer term perspective 

on the geomorphic form and processes of the stream channel.

Data collected during this study were for purposes of 

evaluating only the 2004–05 restoration at Minebank Run. 

Due to the timing of the study, evaluation of geomorphic 

conditions based on the 1998–99 restoration in the headwater 

areas of Minebank Run was not possible. 

Cross-sectional geometry and hydraulic parameters 

presented in this report are limited to data collected from 2005 

through 2008. Information from the 2002 through 2004 field 

surveys were not re-published in this report. The reader should 

refer to Appendix 1 of Doheny and others (2007) to obtain this 

information. 

Longitudinal profiles and cross-sectional characteristics 

were developed based on data that were collected by use of 
Data Limitations 45

Figure 35. Generalized pre-restoration channel bed profile upstream of Sherwood Bridge, Minebank Run study reach, 

early 1960s and 2002.

Figure 36. Generalized post-restoration channel bed profile upstream of Sherwood Bridge, Minebank Run study reach, 

2005 and 2008.

Table 21. Thalweg elevations at cross section Hh from longitudinal profile surveys between 2002 and 2008, 

and corresponding differences from early 1960s channel bed elevation.

[ft, feet; NGVD 29, National Geodetic Vertical Datum of 1929]

Month and year Thalweg elevation at cross section Hh

(ft above NGVD 29)

Difference below early 1960s bed elevation

(ft)

December 2002 219.78 3.4

June 2003 219.44 3.8

January 2004 219.75 3.5

April 2005 219.81 3.4

November 2005 218.48 4.7

September 2006 220.02 3.2

August 2007 220.03 3.2

April 2008 219.99 3.2
46 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

conventional leveling techniques. Although permanent monuments were used to identify and re-survey cross sections, there 

is a degree of difficulty in maintaining the same stations from 

survey to survey, and conventional leveling can include a 

small degree of human error in interpreting readings from the 

survey rod. Due to geomorphic changes in the stream channel 

over time, there is also a small degree of error in maintaining 

exact longitudinal stationing from survey to survey. 

Pebble count data represent a random sampling of particle sizes from the channel bed. As a result, small differences 

in particle-size distribution may, in some cases, be explained 

by random variability of the samples taken from the channel 

bed.

The geomorphic investigation at Minebank Run did not 

include any physical measurements of suspended sediment

or bedload. The computed changes in sediment volume, as 

well as rates of change in the volume of sediment stored and 

removed from the study reach, are based solely on changes 

observed in between cross-sectional surveys in the study reach 

over time.

The comparison of 1960s bed elevations to 2002–08 

study reach conditions is considered preliminary and requires 

more detailed investigation to further confirm the longitudinal 

stationing for comparing pre- and post-restoration conditions. 

The bed profile plotted on the engineering plans was not an 

exact match to the listed scale of 1 in. equals 50 ft (Matz, 

Childs, and Associates, Inc., 1966). In addition, geomorphic 

adjustment of the stream channel over time can cause variability in the longitudinal stationing due to intermediate changes 

in the stream length of the channel between known points 

on the profile. The longitudinal stationing also was affected 

by the physical movement of the stream channel during the 

restoration, which altered the stream length in some locations 

and could add some possible error to direct comparisons of 

pre- and post-restoration bed elevations. 

Summary and Conclusions

In October 2001, the U.S. Geological Survey (USGS), 

the U.S. Environmental Protection Agency (USEPA), and the 

Cary Institute of Ecosystem Studies (CIES) jointly initiated 

a study to investigate the effects of stream restoration on 

stream hydrology, denitrification, and overall water quality in 

a study reach of Minebank Run near Towson, Maryland. In 

response to rapid changes in channel geometry and elevations 

of channel features, as well as the rate of lateral migration of 

the stream channel observed during the first year of the study, 

the USGS was also tasked with measuring and documenting 

the geomorphic changes within the Minebank Run study reach 

before and after physical restoration.

This report presents a geomorphic analysis of pre- and 

post-restoration conditions in the study reach of Minebank 

Run that was based on data collected between water years 

2002 and 2008. Data collected included continuous-record 

streamflow and precipitation; surveyed elevations of the 

channel bed, water surface, and channel features; surveyed 

cross sections; pebble counts from the channel bed; measurements of bed elevation over time in selected locations of the 

study reach; and high-water marks that were retrieved in 

selected locations of the study reach from storm runoff events 

in the watershed.

Investigation of precipitation, discharge intensity, time 

of concentration, flood frequency, and rainfall-runoff relations 

showed that hydrologic conditions were comparable for the 

pre- and post-restoration monitoring periods. Flood frequency 

analysis indicated that the largest peak flows that occurred in 

the Minebank Run watershed during the monitoring period 

could represent events of lower probability when compared 

to a longer peak-flow record in the West Branch Herring 

Run watershed, which shares a drainage area boundary with 

Minebank Run.

Comparison of longitudinal profiles over time indicated 

considerable differences in the distribution and location of 

riffles, pools, and runs in the study reach between 2002 and 

2008. In both the pre-restoration and post-restoration monitoring periods, the analyses indicated that, on average, the stream 

is maintaining the overall slope of the channel bed and water 

surface at about 1 percent in the study reach, despite considerable changes in the percentages of riffles, pools, and runs, and 

changes in the distribution and location of these features in the 

study reach.

On the basis of analysis of the cross sections in both the 

pre- and post-restoration monitoring periods, lateral erosion 

has been reduced considerably with fewer indications of 

any channel widening. Flood flows now have the ability to 

contact sections of the overbank area, and also bypass the 

main channel in small sections of the study reach, which was 

not possible in the pre-restoration monitoring period. Much 

of the geomorphic variability displayed in the post-restoration 

monitoring period is due to aggradation and degradation of 

the channel bed and shifting of the channel thalweg, instead 

of channel degradation and widening, and lateral erosion from 

receding cut banks, which was commonly observed during the 

pre-restoration monitoring period. Most locations in the study 

reach continue to indicate alternating patterns of sediment 

storage and removal over time. At least four of the cross sections indicated reduced variability in cross-sectional area and 

mean depth between surveys conducted from 2006 through 

2008, however. This indicates that the stream channel could be 

establishing a dynamic equilibrium and a more stable geometry after the initial geomorphic response observed in 2005 

and 2006, just after the physical disturbances created by the 

restoration work.

Analyses of hydraulic-geometry relations of selected 

channel variables against discharge indicated moderate to 

strong linear relations for most variables. In the pre-restoration 

monitoring period, the strongest relation was between crosssectional area and discharge. In the post-restoration monitoring period, the strongest relation was between mean flow 

velocity and discharge.

Composite particle-size analyses of the channel bed from 

pebble counts over time indicated that the majority of particle 
Acknowledgments 47

sizes in the Minebank Run study reach fell between fine gravel 

and small cobbles. Median particle diameters found in the 

study reach were 20.5 mm (millimeters) in May–June 2003, 

approximately 1 year prior to restoration of the stream channel, 53.0 mm in May 2005, just after restoration of the stream 

channel, 11.0 mm in October 2006, and 13.0 mm in April 

2008. Sand particles ranged from 8.5 percent to 28.7 percent 

of the cumulative percent finer, with considerable alternating 

increases and decreases over time. This indicates that sources 

of fine sediment, possibly from bank erosion, still exist in 

the watershed despite restoration of the stream channel. The 

abundance of relatively small bed material sizes in combination with flashy streamflow from urban and suburban runoff 

likely contributes to the considerable changes in grain-size 

distribution and alternating periods of storage and transport 

of sand and gravel that have been observed in the study reach 

over time.

Net changes in channel bed elevation measured at 

selected locations indicated that cross section Ee, which was 

one of the most geomorphically unstable locations in the study 

reach prior to restoration, was considerably less prone to rapid 

and extreme changes in bed elevation after restoration of the 

stream channel. Cross section Ff was more prone to lengthy 

periods of sediment storage with rapid removal of stored sediment after restoration, possibly due to the restoration features 

that were implemented in the vicinity of this cross section 

to place more control on the horizontal and vertical adjustments of the stream channel. As in the pre-restoration phase 

of the monitoring, the data from cross section Gg indicate 

periods of relative stability of the channel bed, but also with 

a few periods of rapid vertical changes in bed elevation, and 

relatively smaller amounts of net storage of sediment than at 

cross sections Ee and Ff. All three cross sections appear to 

have undergone a period of considerable vertical adjustment 

between September 2005 and December 2006 based on postrestoration monitoring.

An analysis of boundary shear stress indicated that the 

magnitudes of the boundary shear stresses for post-restoration 

events were comparable to those from the pre-restoration 

period. However, the mean flow velocities at peak discharge 

were somewhat smaller than those during the pre-restoration 

period. The slope of the best-fit line showing the relation 

between boundary shear stress and mean velocity was nearly 

50 percent greater than that for the pre-restoration period. This 

indicates that during the post-restoration monitoring period, a 

larger increase in mean velocity was required to apply a given 

increase in force on the channel bed and bank materials and, in 

turn, to initiate sediment transport.

An analysis of net changes in sediment volume indicated 

that sediment was being removed from the study reach prior 

to restoration, with the largest sediment volume and rate of 

removal occurring from December 2002 through July 2003. 

During the post-restoration period, an alternating pattern of 

sediment removal and storage was observed, with the largest 

sediment volume and rate of removal occurring from April 

2005 through December 2005, just after completion of the 

restoration work. The largest volumes and rates of sediment 

storage during the post-restoration period occurred between 

December 2005 and September 2006. The storm and flood 

of June 25, 2006, which produced a peak discharge of 1,400 

cubic feet per second and is the peak of record at the continuous-record streamgage, is a factor in the volume of sediment 

stored in the study reach during this period.

A comparison of an early 1960s channel bed profile to 

2002–08 study reach conditions indicated that the stream 

channel has maintained an overall slope of about 1 percent 

over a period of 40 to 50 years. All comparisons of bed elevations made between the early 1960s and 2002 indicate that 

the channel bed degraded over time in the Minebank Run 

study reach within an approximate range of 1.3 ft (feet) to 5.0 

ft, with possible local scour of up to 5.6 ft in locations near 

a sanitary sewer pipe that was exposed within the channel 

bed. In the post-restoration condition, evidence indicates that 

the channel bed is still about 0.8 ft to 4.8 ft lower than bed 

elevations from the early 1960s at approximately equivalent 

locations along the profile.

Acknowledgments

The authors would like to thank Kenneth Jewell, Russell 

Neill, and Brad Scoggins of the U.S. Environmental Protection 

Agency, National Risk Management Laboratory, Ada, 

Oklahoma, for extensive assistance in planning and implementation of the study design.

Special thanks are extended to Donald Outen, Karen 

Ogle, Robert Ryan, Steven Stewart, Candice Croswell, 

and Nancy Pentz of the Baltimore County Department of 

Environmental Protection and Sustainability, formerly known 

as the Baltimore County Department of Environmental 

Protection and Resource Management, for planning assistance and technical input on the stream-restoration project at 

Minebank Run.

The authors would like to thank Leo Rebetsky of the 

Baltimore County Department of Recreation and Parks. As 

manager of Cromwell Valley Park, Mr. Rebetsky’s support, 

cooperation, and assistance over the years has been critical to 

successful completion of the project. 

Thanks are extended to Roger Starsoneck, formerly of 

the USGS Maryland-Delaware-D.C. Water Science Center, for 

extensive assistance with planning and implementation of the 

study design, and data-collection efforts. 

Thanks are also extended to Mastin Mount, Elizabeth 

Marchand, and Michael Geissel of the USGS MarylandDelaware-D.C. Water Science Center for their assistance with 

data-collection efforts.

The authors would also like to thank Robert Shedlock, 

Director of the USGS Maryland-Delaware-D.C. Water 

Science Center, and Robert W. James, Jr., formerly of the 

USGS Maryland-Delaware-D.C. Water Science Center, for 

their assistance and support with technical issues and data 

interpretation. 
48 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

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and Resource Management, 2000, aerial photograph of 

Minebank Run watershed: Baltimore County, Maryland, 1 

sheet, scale 1:4,800.

Buchanan, T.J., and Somers, W.P., 1968, Stage measurement 

at gaging stations: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 3, chap. A7, 28 p.

Carter, R.W., and Davidian, J., 1968, General procedures for 

gaging streams: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 3, chap. A6, 13 p.

Crowley, W.P., and Cleaves, E.T., 1974, Geologic map of 

the Towson quadrangle, Maryland: Maryland Geological 

Survey, 1 sheet, scale 1:24,000.

Doheny, E.J., Starsoneck, R.J., Mayer, P.M., and Striz, 

E.A., 2007, Pre-restoration geomorphic characteristics of 

Minebank Run, Baltimore County, Maryland, 2002–04: 

U.S. Geological Survey Scientific Investigations Report 

2007–5127, 49 p., available online at http://pubs.usgs.gov/

sir/2007/5127.

Doheny, E.J., Starsoneck, R.J., Striz, E.A., and Mayer, P.M., 

2006, Watershed characteristics and pre-restoration surfacewater hydrology of Minebank Run, Baltimore County, 

Maryland, water years 2002–04: U.S. Geological Survey 

Scientific Investigations Report 2006–5179, 42 p., available 

online at http://pubs.usgs.gov/sir/2006/5179.

Groffman, P.M., Dorsey, A.M., and Mayer, P.M., 2005, N 

processing within geomorphic structures in urban streams: 

Journal of the North American Benthological Society, v. 24, 

no. 3, p. 613–625.

Harrelson, C.C., Rawlins, C.L., and Potyondy, J.P., 1994, 

Stream channel reference sites: An illustrated guide to 

field technique: Fort Collins, Colorado, U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station, General Technical Report 

RM–245, 61 p.

Harrison, M.D., Groffman, P.M., Mayer, P.M., Kaushal, S.S., 

and Newcomer, T.A., 2011, Denitrification in alluvial 

wetlands in an urban landscape: Journal of Environmental 

Quality, v. 40, no. 2, p. 634–646, DOI: 10.2134/

jeq2010.0335.

Haschenburger, J.K., and Roest, P., 2008, Substrate indices as 

indicators of interstitial pore space in gravel-bed channels: 

River Research and Applications, v. 25, no. 1, p. 98–105, 

DOI: 10.1002/rra. 1168.

Interagency Advisory Committee on Water Data, 1982, 

Guidelines for determining flood flow frequency: Reston, 

Virginia, Water Resources Council Bulletin 17B, 28 p.

Kaushal, S., Groffman, P.M., Mayer, P.M., Striz, E., and Gold, 

A., 2008, Effects of stream restoration on denitrification in 

an urbanizing watershed: Ecological Applications, v. 18, 

no. 3, p. 789–804.

Leopold, L.B., 1994, A view of the river: Cambridge, 

Massachusetts, Harvard University Press, 298 p.

Lutz, L., 2006, Minebank Run restoration hits pay dirt in 

reducing nitrogen loads, in Chesapeake Bay Journal, 

October 2006, vol. 16, no.7, 4 p., accessed April 27, 2011 at 

http://www.bayjournal.com/article.cfm?article=2904.

Maryland State Climatologist Office, 2011, Baltimore 

average monthly precipitation (since 1871), accessed May 

2, 2011 at http://www.atmos.umd.edu/~climate/Weather/

marylandnormals.htm.

Matz, Childs, and Associates, Inc., 1966, Plan and profile 

of proposed section III—Gunpowder interceptor and 

Minebank Run sub-interceptor from Baltimore County 

Beltway to Glenarm Road: Prepared for the Baltimore 

County, Maryland Department of Public Works, Contract 

no. 1040-S, 11 sheets, horizontal scale: 1 inch = 50 feet, 

vertical scale: 1 inch = 5 feet.

Mayer, P.M., Groffman, P.M., Striz, E., and Kaushal, S.S., 

2010, Nitrogen dynamics at the groundwater-surface 

water interface of a degraded urban stream: Journal of 

Environmental Quality, v. 39, no. 3, p. 810–823.

Mayer, Paul, Striz, Elise, Shedlock, Robert, Doheny, Edward, 

and Groffman, Peter, 2003, The effects of ecosystem restoration on nitrogen processing in an urban Mid-Atlantic 

Piedmont stream, in Renard, K.G., McElroy, S.A., Gburek, 

W.J., Canfield, H.E., and Scott, R.L., eds., Proceedings 

of the First Interagency Conference on Research in the 

Watersheds, Tucson, Arizona, October 27–30, 2003, U.S. 

Department of Agriculture, Agricultural Research Service, 

p. 536–541, accessed November 23, 2011 at http://www.

tucson.ars.ag.gov/icrw/Proceedings/Mayer.pdf.

Paul, M.J., and Meyer, J.L., 2001, Streams in the urban landscape: Annual Review of Ecology and Systematics, v. 32, 

p. 333–365.

Rosgen, D.L., 1993, Applied fluvial geomorphology, training 

manual, river short course: Pagosa Springs, Colorado, 

Wildland Hydrology, 450 p.

Rosgen, D.L., 1996, Applied river morphology: Pagosa 

Springs, Colorado, Wildland Hydrology, 365 p.
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Shields, A., 1936, Application of similarity principles and 

turbulence research to bedload movement, translated by 

W.P. Ott and J.C. Uchelen: Pasadena, California, California 

Institute of Technology Report No. 167, 43 p.

Striz, E.A., and Mayer, P.M., 2008, Assessment of nearstream ground water-surface water interaction (GSI) of a 

degraded stream before restoration: U.S. Environmental 

Protection Agency report EPA/600/R-07/058, 42 p., 

accessed December 16, 2011 at http://www.epa.gov/nrmrl/

pubs/600.07058/600r07058.pdf.

U.S. Geological Survey, 2009, Water-resources data for the 

United States, Water Year 2008: U.S. Geological Survey 

Water-Data Report WDR–US–2008, site 0158397967, 

accessed May 2, 2011, at http://wdr.water.usgs.gov/wy2008/

pdfs/0158397967.2008.pdf.

Wolman, M.G., 1954, A method of sampling coarse river-bed 

material: Transactions of the American Geophysical Union, 

v. 35, no. 6, p. 951–956.

Glossary 51

Glossary

A

Aggradation An increase in elevation of the 

channel bed, banks, or overbank areas of an 

alluvial river due to deposition of sediment. 

Alluvium Sedimentary material that was 

deposited by flowing water. Examples of 

alluvial deposits include deltas, point bars, 

and sand in the flood-plain areas of rivers or 

streams.

B

Bedload Particles of sand, gravel, or soil 

from the channel bed that are transported by 

the natural flow of a stream or river on or 

immediately above the channel bed.

Boundary shear stress The force, in pounds 

per square foot, that flowing water applies to 

the channel bed and banks of a stream.

C

Colluvium Loose deposits of collapsed rock 

debris that accumulate at the base of a cliff or 

sloping valley.

Continuous-record streamgage Location 

where a water-stage recorder is used to collect 

continuous time-series stage data that are 

related to systematic discharge measurements 

at the station. Continuous-record streamgages 

are often operated for the purpose of longterm monitoring or as part of hydrologic 

investigations.

Crest-stage gage A device that will register 

the peak stage of the stream occurring 

between inspections of the gage. Crest-stage 

gages are typically used as a supplement to 

a water-stage recorder since the peak stage 

of a storm can occur in between recorded 

stage values. Crest-stage gages can be used to 

obtain high-water marks at a given location 

during a flood, or to determine water-surface 

slopes at different stream stages if placed in 

multiple locations along a reach of stream. 

A stage-discharge relation for the location 

of a crest-stage gage can be developed using 

discharge data obtained by indirect measurements of peak flow, or direct measurement 

of a range of discharges by use of a current 

meter or acoustic Doppler current profiler.

D

Degradation A decrease in elevation of the 

channel bed, banks, or overbank areas of an 

alluvial river due to erosion of sediment.

Dynamic equilibrium A steady-state condition where the net effect of flowing water is 

neither erosion of the channel bed nor deposition of sediment. Dynamic equilibrium generally occurs when there is balance between 

sediment input and sediment transport in a 

stream or river.

E

Event-mean discharge The mean discharge 

of a storm event, computed by dividing the 

total volume of direct runoff by the length of 

time in which that runoff occurs.

F

Fall Line The line marking the point on each 

stream where the flow descends from the 

eastern section of the Piedmont Physiographic 

Province to the western section of the Coastal 

Plain Physiographic Province in Maryland. 

The Fall Line is characterized by an abrupt 

decrease in channel slope in transition 

between the Piedmont and the Coastal Plain 

Physiographic Provinces. 

Flashy A stream or watershed that tends to 

produce narrow, steeply peaked storm hydrographs that rise and fall very quickly.

Flood frequency Flood-frequency analysis is 

a method of estimating the chance that a peak 

discharge of a given magnitude will occur in 

any given year. The larger the magnitude of 

the discharge, the smaller the chance is that 

this discharge will occur in a given year. The 

analysis is based on recorded discharge data, 

specifically on the annual-peak series that are 

derived from streamgage data. This dataset 

consists of the largest instantaneous discharge, 

or peak flow, that occurs in each water year 

during which data collection occurred. The 
52 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

larger the dataset, the greater the confidence 

that can be assigned to the estimates derived 

from it.

G

Geomorphic Of, or pertaining to, the scientific study of landforms and the processes that 

shape them.

H

Hydraulic radius The cross-sectional area of 

a channel divided by the wetted perimeter. 

L

Lateral erosion Erosion in which the 

removal of bank material extends laterally 

from the toe of the bank.

P

Percent finer A cumulative percentage, 

associated with a particular particle size or 

diameter, that represents how much of the 

material that composes the channel bed or 

banks is smaller, or finer, than that particle 

diameter. 

Piezometer An open-ended vertical pipe 

that is used for measurement of pressure and 

changes in pressure at a selected depth within 

an aquifer.

Porosity The ratio of the volume of voids to 

the total volume of a soil sample. Porosity is 

typically expressed as a percentage between 0 

and 100 percent.

Probability A number expressing the statistical chance or likelihood that a storm event of 

a given magnitude will occur. 

R

Rainfall-runoff relations The relation 

between the quantity of rain that falls during 

a precipitation event and the resulting amount 

of runoff that is conveyed by a stream channel. Rainfall-runoff relations are investigated 

as a means to quantify the hydrologic 

response of a watershed. 

Relief The variation between the highest 

and lowest elevations at any location in a 

watershed, using a common elevation datum.

Riparian Relating to, living, or located on 

the bank of a natural watercourse, such as a 

river, stream, lake, or tidewater.

Riprap A layer or facing of rock that is 

placed to protect a bridge, embankment, or 

channel bank from erosion. 

Run A longitudinal section of stream channel that has a moderate current, moderate 

depth, and a relatively smooth water surface. 

S

Sinuosity The ratio of stream length to valley length. The minimum value for sinuosity 

is 1.0 for a straight channel, and increases 

depending on the amount of meandering in 

the reach of interest. 

Stability The ability of a stream or river to 

transport its flow and sediment while maintaining its dimension, pattern, and profile with 

no net change in aggradation or degradation.

Suspended sediment Sediment in flowing 

water that is maintained in suspension by the 

upward components of turbulent currents in a 

stream or river.

T

Thalweg The lowest elevation across a 

cross section in a stream channel.

Time of concentration The length of time 

between the start of precipitation and the 

start of the corresponding increase in stream 

discharge at a point. 

W

Water year The 12-month period beginning 

October 1 and ending September 30. The 

water year is designated by the calendar year 

in which it ends. For example, the year beginning October 1, 2005 and ending September 

30, 2006 is called “water year 2006.”

Wetted perimeter The length along the 

cross-sectional boundary of a channel that is 

contacted by water at a given elevation. In an 

open channel, such as a stream or river, the 

cross-sectional boundary is the channel bed 

and banks. 
Appendix 1 53

Appendix 1
54 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Appendix 1. Changes in cross-section geometry at permanent cross section Aa, Minebank Run study reach, 2005 through 2008.

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Dec., December; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

212.00 28.1 21.9

(-22.1%)

27.9

(-0.7%)

27.4

(-2.5%)

28.8

(+2.5%)

31.0 28.8 32.0 33.3 32.8

212.50 44.6 37.9

(-15.0%)

44.5

(-0.2%)

44.5

(-0.2%)

45.8

(+2.7%)

36.8 36.1 37.4 37.1 37.2

213.00 63.8 57.1

(-10.5%)

63.7

(-0.2%)

63.7

(-0.2%)

64.9

(+1.7%)

41.2 41.5 42.2 41.6 42.1

213.50 85.5 78.7

(-8.0%)

85.2

(-0.4%)

85.1

(-0.5%)

86.1

(+0.7%)

45.9 45.7 46.6 46.0 45.6

214.00 108.9 101.9

(-6.4%)

108.5

(-0.4%)

108.7

(-0.2%)

108.8

(-0.1%)

50.0 49.0 50.4 50.7 48.7

214.50 155.7 146.5

(-5.9%)

155.5

(-0.1%)

153.5

(-1.4%)

154.2

(-1.0%)

84.8 85.0 86.0 85.0 85.1

215.00 198.4 189.4

(-4.5%)

198.4

(0.0%)

196.3

(-1.1%)

196.8

(-0.8%)

88.9 89.1 89.8 89.0 89.1

215.50 243.2 234.2

(-3.7%)

243.1

(0.0%)

241.1

(-0.9%)

241.4

(-0.7%)

92.9 92.7 93.9 93.7 94.8

216.00 289.7 281.3

(-2.9%)

290.2

(+0.2%)

288.5

(-0.4%)

289.5

(-0.1%)

96.7 102.2 99.3 99.1 102.5

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

212.00 0.91 0.76 0.87 0.82 0.88 30.6 28.4 30.6 32.6 31.6 0.92 0.77 0.91 0.84 0.91

212.50 1.21 1.05 1.19 1.20 1.23 36.2 35.5 36.0 36.2 35.8 1.23 1.07 1.24 1.23 1.28

213.00 1.55 1.38 1.51 1.53 1.54 40.5 40.9 40.6 40.7 40.6 1.58 1.40 1.57 1.57 1.60

213.50 1.86 1.72 1.83 1.85 1.89 45.0 45.0 44.9 44.9 43.9 1.90 1.75 1.90 1.90 1.96

214.00 2.18 2.08 2.15 2.14 2.23 48.9 48.0 48.5 49.5 46.9 2.23 2.12 2.24 2.20 2.32

214.50 1.84 1.72 1.81 1.81 1.81 83.5 83.8 83.9 83.6 83.0 1.86 1.75 1.85 1.84 1.86

215.00 2.23 2.13 2.21 2.21 2.21 87.5 87.7 87.6 87.5 86.9 2.27 2.16 2.26 2.24 2.26

215.50 2.62 2.53 2.59 2.57 2.55 91.3 91.2 91.6 92.1 92.5 2.66 2.57 2.65 2.62 2.61

216.00 3.00 2.75 2.92 2.91 2.82 95.0 100.6 96.8 97.3 100.1 3.05 2.80 3.00 2.97 2.89

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
Appendix 1 55

Appendix 1. Changes in cross-section geometry at permanent cross section Bb, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Dec., December; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

212.17 6.5 14.7

(+126.2%)

19.9

(+206.2%)

21.6

(+232.3%)

23.4

(+260.0%)

27.9 27.6 27.6 26.6 27.9

212.50 16.0 23.9

(+49.4%)

29.0

(+81.3%)

30.5

(+90.6%)

32.8

(+105.0%)

29.7 29.2 29.0 28.3 29.9

213.00 31.3 39.0

(+24.6%)

43.8

(+39.9%)

45.1

(+44.1%)

48.0

(+53.4%)

32.3 32.0 31.6 31.2 32.5

213.50 48.0 55.6

(+15.8%)

60.0

(+25.0%)

61.1

(+27.3%)

64.4

(+34.2%)

35.3 36.0 35.2 34.8 35.2

214.00 66.2 74.0

(+11.8%)

78.1

(+18.0%)

79.1

(+19.5%)

82.4

(+24.5%)

38.9 39.3 38.8 38.8 39.2

214.50 86.2 94.1

(+9.2%)

97.9

(+13.6%)

99.0

(+14.8%)

102.5

(+18.9%)

42.8 43.3 43.1 42.8 43.5

215.00 108.7 116.9

(+7.5%)

120.4

(+10.8%)

121.2

(+11.5%)

125.1

+15.1%)

49.4 49.7 49.7 49.0 50.5

215.50 135.7 144.1

(+6.2%)

147.6

(+8.8%)

146.9

(+8.3%)

152.1

(+12.1%)

58.9 59.4 60.2 56.4 59.9

216.00 165.9 174.7

(+5.3%)

178.3

(+7.5%)

176.3

(+6.3%)

182.7

(+10.1%)

64.5 65.5 65.8 63.8 65.8

216.50 200.2 209.4

(+4.6%)

212.5

(+6.1%)

209.7

(+4.7%)

216.8

(+8.3%)

76.5 77.2 76.2 77.6 75.9

216.54 203.3 212.4

(+4.5%)

215.5

(+6.0%)

212.8

(+4.7%)

219.9

(+8.2%)

77.9 77.9 77.0 81.2 80.8

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

212.17 0.23 0.53 0.72 0.81 0.84 27.8 27.4 27.2 26.2 27.4 0.23 0.54 0.73 0.82 0.85

212.50 0.54 0.82 1.00 1.08 1.10 29.5 28.9 28.5 27.8 29.3 0.54 0.83 1.02 1.10 1.12

213.00 0.97 1.22 1.39 1.45 1.48 31.9 31.4 30.8 30.5 31.7 0.98 1.24 1.42 1.48 1.51

213.50 1.36 1.54 1.70 1.76 1.83 34.8 35.3 34.3 33.9 34.1 1.38 1.58 1.75 1.80 1.89

214.00 1.70 1.88 2.01 2.04 2.10 38.2 38.5 37.8 37.8 37.9 1.73 1.92 2.07 2.09 2.17

214.50 2.01 2.17 2.27 2.31 2.36 42.0 42.3 41.9 41.7 42.1 2.05 2.22 2.34 2.37 2.43

215.00 2.20 2.35 2.42 2.47 2.48 48.5 48.6 48.4 47.8 49.0 2.24 2.41 2.49 2.54 2.55

215.50 2.30 2.43 2.45 2.60 2.54 57.9 58.2 58.8 55.1 58.3 2.34 2.48 2.51 2.67 2.61

216.00 2.57 2.67 2.71 2.76 2.78 63.4 64.2 64.3 62.5 64.2 2.62 2.72 2.77 2.82 2.85

216.50 2.62 2.71 2.79 2.70 2.86 75.3 75.9 74.6 76.2 74.3 2.66 2.76 2.85 2.75 2.92

216.54 2.61 2.73 2.80 2.62 2.72 76.8 76.6 75.4 79.9 79.1 2.65 2.77 2.86 2.66 2.78

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
56 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Appendix 1. Changes in cross-section geometry at permanent cross section Cc, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Dec., December; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

214.05 16.6 21.6

(+30.1%)

26.2

(+57.8%)

22.9

(+38.0%)

20.6

(+24.1%)

27.5 25.1 26.1 25.0 25.0

214.50 29.3 33.2

(+13.3%)

38.0

(+29.7%)

35.1

(+19.8%)

32.6

(+11.3%)

29.9 27.9 28.8 30.2 30.3

215.00 44.9 48.3

(+7.6%)

53.1

(+18.3%)

50.7

(+12.9%)

48.3

(+7.6%)

34.2 34.1 33.7 33.5 33.8

215.50 66.3 70.1

(+5.7%)

71.9

(+8.4%)

68.2

(+2.9%)

66.5

(+0.3%)

61.3 61.6 56.1 41.1 50.9

215.95 96.8 100.5

(+3.8%)

101.8

(+5.2%)

95.1

(-1.8%)

95.9

(-0.9%)

71.4 71.3 71.6 71.7 70.9

216.50 136.7 140.6

(+2.9%)

142.1

(+4.0%)

135.4

(-1.0%)

136.3

(-0.3%)

76.6 76.4 78.0 77.4 79.1

217.00 176.4 180.0

(+2.0%)

182.2

(+3.3%)

175.5

(-0.5%)

177.1

(+0.4%)

84.5 83.8 85.0 86.2 87.2

217.50 219.6 223.1

(+1.6%)

225.3

(+2.6%)

220.0

(+0.2%)

221.1

(+0.7%)

90.9 90.8 90.9 93.9 91.6

218.00 267.1 270.1

(+1.1%)

272.3

(+1.9%)

270.4

(+1.2%)

268.1

+0.4%)

104.0 102.8 102.6 110.7 101.7

218.11 278.6 281.6

(+1.1%)

283.8

(+1.9%)

282.7

(+1.5%)

279.3

(+0.3%)

106.7 108.1 109.7 114.4 105.4

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

214.05 0.60 0.86 1.00 0.92 0.82 27.2 24.8 25.4 24.5 24.5 0.61 0.87 1.03 0.93 0.84

214.50 0.98 1.19 1.32 1.16 1.08 29.3 27.4 27.8 29.6 29.7 1.00 1.21 1.37 1.19 1.10

215.00 1.31 1.42 1.58 1.49 1.43 33.5 33.5 32.6 32.7 33.1 1.34 1.44 1.63 1.55 1.46

215.50 1.08 1.14 1.28 1.66 1.31 60.5 60.8 54.8 40.2 50.1 1.10 1.15 1.31 1.70 1.33

215.95 1.36 1.41 1.42 1.33 1.35 70.4 70.4 70.3 70.7 69.9 1.38 1.43 1.45 1.35 1.37

216.50 1.78 1.84 1.82 1.75 1.72 75.5 75.4 76.5 76.2 78.0 1.81 1.86 1.86 1.78 1.75

217.00 2.09 2.15 2.14 2.04 2.03 83.3 82.7 83.4 85.0 85.9 2.12 2.18 2.18 2.06 2.06

217.50 2.42 2.46 2.48 2.34 2.41 89.6 89.6 89.2 92.6 90.3 2.45 2.49 2.53 2.38 2.45

218.00 2.57 2.63 2.65 2.44 2.64 102.7 101.5 100.9 109.4 100.3 2.60 2.66 2.70 2.47 2.67

218.11 2.61 2.60 2.59 2.47 2.65 105.3 106.8 108.0 113.1 103.9 2.65 2.64 2.63 2.50 2.69

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
Appendix 1 57

Appendix 1. Changes in cross-section geometry at permanent cross section Dd, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Dec., December; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

215.00 0.4 5.4

(+1,250.0%)

2.5

(+525.0%)

1.8

(+350.0%)

2.9

(+625.0%)

5.4 19.0 12.6 8.9 12.7

215.50 9.0 16.1

(+78.9%)

12.4

(+37.8%)

8.8

(-2.2%)

12.2

(+35.6%)

24.2 23.9 22.9 19.5 23.0

216.00 22.5 28.6

(+27.1%)

24.2

(+7.6%)

19.7

(-12.4%)

25.3

(+12.4%)

29.5 27.5 26.7 24.8 28.9

216.50 37.8 42.8

(+13.2%)

38.3

(+1.3%)

33.4

(-11.6%)

40.3

(+6.6%)

32.4 31.7 31.2 30.6 32.5

217.00 54.5 59.3

(+8.8%)

54.4

(-0.2%)

49.7

(-8.8%)

56.8

(+4.2%)

35.3 36.0 35.6 35.4 36.0

217.50 72.7 77.7

(+6.9%)

72.7

(0.0%)

68.3

(-6.1%)

75.4

(+3.7%)

39.0 39.8 39.8 40.1 40.8

218.00 92.7 98.0

(+5.7%)

93.0

(+0.3%)

89.1

(-3.9%)

96.0

(+3.6%)

42.4 44.0 44.4 44.7 44.7

218.38 109.3 115.1

(+5.3%)

110.4

(+1.0%)

106.4

(-2.7%)

113.4

(+3.8%)

47.5 49.0 50.2 48.2 49.8

218.50 115.0 120.9

(+5.1%)

116.4

(+1.2%)

112.2

(-2.4%)

166.4

(+44.7%)

48.9 51.4 54.1 49.4 107.7

218.75 187.7 193.8

(+3.2%)

190.3

(+1.4%)

188.9

(+0.6%)

193.2

(+2.9%)

113.7 113.2 112.0 114.9 112.0

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008 Apr.2005

Dec.

2005 2006 2007 2008

215.00 0.074 0.28 0.20 0.20 0.23 5.3 18.5 12.5 8.8 12.5 0.075 0.29 0.20 0.20 0.23

215.50 0.37 0.67 0.54 0.45 0.53 24.1 23.2 22.3 19.3 22.4 0.37 0.69 0.56 0.46 0.54

216.00 0.76 1.04 0.91 0.79 0.88 29.3 26.7 25.9 24.5 28.1 0.77 1.07 0.93 0.80 0.90

216.50 1.17 1.35 1.23 1.09 1.24 31.9 30.7 30.2 30.2 31.5 1.18 1.39 1.27 1.11 1.28

217.00 1.54 1.65 1.53 1.40 1.58 34.7 34.9 34.5 34.8 34.8 1.57 1.70 1.58 1.43 1.63

217.50 1.86 1.95 1.83 1.70 1.85 38.2 38.6 38.6 39.4 39.5 1.90 2.01 1.88 1.73 1.91

218.00 2.19 2.23 2.09 1.99 2.15 41.6 42.6 43.0 43.9 43.3 2.23 2.30 2.16 2.03 2.22

218.38 2.30 2.35 2.20 2.21 2.28 46.5 47.6 48.8 47.4 48.3 2.35 2.42 2.26 2.24 2.35

218.50 2.35 2.35 2.15 2.27 1.55 48.0 49.9 52.6 48.4 105.2 2.40 2.42 2.21 2.32 1.58

218.75 1.65 1.71 1.70 1.64 1.73 112.0 111.0 109.5 113.1 109.5 1.68 1.75 1.74 1.67 1.76

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
58 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Appendix 1. Changes in cross-section geometry at permanent cross section Ee, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Nov., November; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

216.50 4.4 9.2

(+109.1%)

8.0

(+81.8%)

8.1

(+84.1%)

7.9

(+79.5%)

15.2 12.4 14.8 14.1 14.7

217.00 14.7 16.7

(+13.6%)

16.8

(+14.3%)

16.5

(+12.2%)

16.7

(+13.6%)

25.3 18.2 21.5 21.7 23.7

217.50 29.2 26.6

(-8.9%)

29.0

(-0.7%)

28.6

(-2.1%)

29.3

(+0.3%)

32.5 24.2 28.3 28.4 28.6

218.00 46.7 42.2

(-9.6%)

43.6

(-6.6%)

43.3

(-7.3%)

43.9

(-6.0%)

38.0 37.3 33.2 33.2 32.6

218.50 66.4 61.8

(-6.9%)

61.1

(-8.0%)

60.7

(-8.6%)

61.0

(-8.1%)

41.7 42.0 39.4 39.3 39.5

219.00 87.3 82.8

(-5.2%)

81.5

(-6.6%)

80.9

(-7.3%)

81.5

(-6.6%)

44.0 44.4 43.8 44.3 44.5

219.38 104.8 100.4

(-4.2%)

98.1

(-6.4%)

97.7

(-6.8%)

98.2

(-6.3%)

54.9 56.3 46.7 47.3 47.2

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

216.50 0.29 0.74 0.54 0.57 0.54 15.0 11.9 14.4 13.5 14.0 0.29 0.77 0.56 0.60 0.56

217.00 0.58 0.92 0.78 0.76 0.70 24.9 17.5 20.8 20.6 22.7 0.59 0.95 0.81 0.80 0.74

217.50 0.90 1.10 1.02 1.01 1.02 32.0 23.4 27.3 27.1 27.3 0.91 1.14 1.06 1.06 1.07

218.00 1.23 1.13 1.31 1.30 1.35 37.4 36.4 32.0 31.7 31.1 1.25 1.16 1.36 1.37 1.41

218.50 1.59 1.47 1.55 1.54 1.54 40.9 40.9 38.1 37.8 37.9 1.62 1.51 1.60 1.61 1.61

219.00 1.98 1.86 1.86 1.83 1.83 43.0 43.1 42.3 42.6 42.8 2.03 1.92 1.93 1.90 1.90

219.38 1.91 1.78 2.10 2.07 2.08 53.7 54.9 45.1 45.5 45.4 1.95 1.83 2.18 2.15 2.16

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
Appendix 1 59

Appendix 1. Changes in cross-section geometry at permanent cross section Ff, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Nov., November; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

219.00 26.9 22.1

(-17.8%)

29.0

(+7.8%)

28.8

(+7.1%)

30.7

(+14.1%)

26.1 21.9 21.4 26.7 27.3

219.50 40.2 34.0

(-15.4%)

40.2

(0.0%)

42.2

(+5.0%)

43.7

(+8.7%)

32.9 26.6 27.2 31.2 31.2

220.00 57.7 51.4

(-10.9%)

56.0

(-2.9%)

58.3

(+1.0%)

60.1

(+4.2%)

39.8 40.3 38.1 39.0 43.2

220.50 77.1 71.8

(-6.9%)

76.0

(-1.4%)

77.8

(+0.9%)

80.2

(+4.0%)

42.9 43.6 44.2 44.2 45.4

221.00 98.1 93.5

(-4.7%)

97.7

(-0.4%)

98.8

(+0.7%)

101.6

(+3.6%)

46.4 46.1 48.5 47.1 49.9

221.50 120.9 116.6

(-3.6%)

121.2

(+0.2%)

122.2

(+1.1%)

124.8

(+3.2%)

51.8 50.6 51.7 54.4 53.6

222.00 302.7 303.5

(+0.3%)

308.1

(+1.8%)

306.1

(+1.1%)

309.9

(+2.4%)

142.1 142.4 144.1 143.6 146.9

222.34 350.5 352.1

(+0.5%)

357.3

(+1.9%)

353.8

(+0.9%)

359.3

(+2.5%)

149.1 152.2 150.6 147.1 155.8

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

219.00 1.03 1.01 1.36 1.08 1.12 24.7 21.3 20.0 25.1 24.6 1.09 1.04 1.45 1.15 1.25

219.50 1.22 1.28 1.48 1.35 1.40 31.1 25.7 25.4 29.2 28.1 1.29 1.32 1.58 1.45 1.56

220.00 1.45 1.28 1.47 1.49 1.39 37.4 39.2 36.1 36.1 39.3 1.54 1.31 1.55 1.61 1.53

220.50 1.80 1.65 1.72 1.76 1.77 40.2 42.1 41.8 40.8 41.0 1.92 1.71 1.82 1.91 1.96

221.00 2.11 2.03 2.01 2.10 2.04 43.4 44.5 45.5 43.2 44.9 2.26 2.10 2.15 2.29 2.26

221.50 2.33 2.30 2.34 2.25 2.33 48.6 48.8 48.6 50.3 48.5 2.49 2.39 2.49 2.43 2.57

222.00 2.13 2.13 2.14 2.13 2.11 138.2 139.9 140.4 138.7 141.2 2.19 2.17 2.19 2.21 2.19

222.34 2.35 2.31 2.37 2.41 2.31 145.1 149.7 146.8 142.1 150.0 2.42 2.35 2.43 2.49 2.40

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
60 Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08

Appendix 1. Changes in cross-section geometry at permanent cross section Gg, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Nov., November; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

220.80 52.7 61.0

(+15.7%)

41.0

(-22.2%)

42.0

(-20.3%)

41.8

(-20.7%)

36.0 37.1 34.7 34.6 34.2

221.00 59.9 68.4

(+14.2%)

47.8

(-20.2%)

48.9

(-18.4%)

48.6

(-18.9%)

38.6 39.1 35.7 36.1 35.7

221.50 79.3 88.2

(+11.2%)

66.6

(-16.0%)

68.1

(-14.1%)

67.7

(-14.6%)

41.3 42.8 41.4 41.4 41.6

222.00 99.3 108.8

(+9.6%)

87.1

(-12.3%)

88.9

(-10.5%)

88.7

(-10.7%)

42.9 44.5 44.1 44.2 44.8

222.50 120.3 130.3

(+8.3%)

109.1

(-9.3%)

110.9

(-7.8%)

111.1

(-7.6%)

45.7 47.2 47.5 46.9 47.6

223.00 142.7 153.1

(+7.3%)

132.6

(-7.1%)

134.0

(-6.1%)

134.8

(-5.5%)

49.2 50.5 51.0 49.6 50.9

223.48 171.1 181.7

(+6.2%)

161.5

(-5.6%)

161.7

(-5.5%)

164.3

(-4.0%)

65.2 64.6 62.8 62.4 63.3

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

220.80 1.46 1.64 1.18 1.21 1.22 34.7 35.6 33.6 33.8 33.4 1.52 1.71 1.22 1.24 1.25

221.00 1.55 1.75 1.34 1.35 1.36 37.1 37.4 34.5 35.3 34.7 1.61 1.83 1.39 1.39 1.40

221.50 1.92 2.06 1.61 1.64 1.63 39.5 40.7 39.9 40.2 40.4 2.01 2.17 1.67 1.69 1.68

222.00 2.31 2.44 1.98 2.01 1.98 40.7 41.9 42.3 42.8 43.4 2.44 2.60 2.06 2.08 2.04

222.50 2.63 2.76 2.30 2.36 2.33 43.3 44.1 45.5 45.1 46.0 2.78 2.95 2.40 2.46 2.42

223.00 2.90 3.03 2.60 2.70 2.65 46.6 47.1 48.8 47.5 49.1 3.06 3.25 2.72 2.82 2.75

223.48 2.62 2.81 2.57 2.59 2.60 62.3 61.0 60.4 60.0 61.3 2.75 2.98 2.67 2.70 2.68

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.
Appendix 1 61

Appendix 1. Changes in cross-section geometry at permanent cross section Ii, Minebank Run study reach, 2005 through 2008.

—Continued

[NGVD 29, National Geodetic Vertical Datum of 1929; ft, feet; ft2, square feet; Apr., April; Nov., November; %, percent]

Elevation

(ft above

NGVD 29)

Cross-sectional area

(ft2)

Wetted perimeter

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

224.00 44.2 40.3

(-8.8%)

38.7

(-12.4%)

36.7

(-17.0%)

37.8

(-14.5%)

30.2 31.6 30.4 29.8 30.4

224.50 59.3 55.5

(-6.4%)

53.4

(-9.9%)

51.3

(-13.5%)

52.7

(-11.1%)

32.3 33.8 32.9 32.0 32.8

225.00 75.5 71.4

(-5.4%)

69.1

(-8.5%)

66.8

(-11.5%)

68.3

(-9.5%)

34.8 35.7 34.8 34.5 34.7

225.50 92.7 88.4

(-4.6%)

85.8

(-7.4%)

83.9

(-9.5%)

85.1

(-8.2%)

37.0 39.4 38.5 39.4 38.8

226.00 110.9 106.6

(-3.9%)

103.8

(-6.4%)

102.5

(-7.6%)

103.3

(-6.9%)

39.5 41.7 40.9 41.8 41.1

226.50 130.0 125.8

(-3.2%)

122.8

(-5.5%)

122.1

(-6.1%)

122.3

(-5.9%)

41.3 43.8 43.0 44.1 43.0

227.00 150.2 146.2

(-2.7%)

142.7

(-5.0%)

142.8

(-4.9%)

142.5

(-5.1%)

46.4 50.5 45.6 46.6 48.6

Elevation

(ft above

NGVD 29)

Hydraulic radius

(ft)

Channel width

(ft)

Mean channel depth

(ft)

Apr.

2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008 Apr.2005

Nov.

2005 2006 2007 2008

224.00 1.46 1.28 1.27 1.23 1.24 29.3 29.4 28.5 28.4 28.6 1.51 1.37 1.36 1.29 1.32

224.50 1.84 1.64 1.62 1.60 1.61 31.1 31.1 30.6 30.1 30.6 1.91 1.78 1.75 1.70 1.72

225.00 2.17 2.00 1.99 1.94 1.97 33.4 32.5 32.0 32.1 31.9 2.26 2.20 2.16 2.08 2.14

225.50 2.51 2.24 2.23 2.13 2.19 35.3 35.5 35.0 36.2 35.3 2.63 2.49 2.45 2.32 2.41

226.00 2.81 2.56 2.54 2.45 2.51 37.6 37.5 37.1 38.2 37.3 2.95 2.84 2.80 2.68 2.77

226.50 3.15 2.87 2.86 2.77 2.84 39.0 39.3 38.9 40.3 38.7 3.33 3.20 3.16 3.03 3.16

227.00 3.24 2.90 3.13 3.06 2.93 43.9 45.6 41.1 42.5 44.0 3.42 3.21 3.47 3.36 3.24

Note: Percentages shown in parentheses under cross-sectional areas represent the percent change in area from the April 2005 survey.

Prepared by USGS West Trenton Publishing Service Center.

Edited by Valerie M. Gaine.

Graphics and layout by Timothy W. Auer.

For additional information, contact:

Edward J. Doheny, Hydrologist

443-498-5535

or Director, MD-DE-DC Water Science Center

U.S. Geological Survey

5522 Research Park Drive

Baltimore, MD 21228

443-498-5500

or visit our Web site at:

http://md.water.usgs.gov
Doheny, E.J., and others—Geomorphic Responses to Stream Channel Restoration at Minebank Run, Baltimore County, Maryland, 2002–08—Scientific Investigations Report 2012–5012

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