Cover photographs and credits (from left):

Pupal and larval blackflies (Simulium sp.) in riffle habitat. (Photograph by Robert Zuellig, 

U.S. Geological Survey)

Stormflow at Cottonwood Creek Tributary above Rangewood Drive, at Colorado Springs, 

Colorado. (Photograph by Robert Stogner, U.S. Geological Survey)

Male and female Red Shiner (Cyprinella lutrensis) exhibiting spawning behavior. 

(Photograph by Robert Zuellig, U.S. Geological Survey)
Urban-Related Environmental Variables 

and Their Relation with Patterns in 

Biological Community Structure in the 

Fountain Creek Basin, Colorado, 2003–2005

By Robert E. Zuellig, James F. Bruce, Erin E. Evans, and Robert W. Stogner

Prepared in cooperation with Colorado Springs City Engineering

Scientific Investigations Report 2007–5225

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2008

For product and ordering information:

World Wide Web: http://www.usgs.gov/pubprod

Telephone: 1-888-ASK-USGS

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment:

World Wide Web: http://www.usgs.gov

Telephone: 1-888-ASK-USGS

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Zuellig, R.E., Bruce, J.F., Evans, E.E., and Stogner, R.W., 2008, Urban-related environmental variables and their relation 

with patterns in biological community structure in the Fountain Creek Basin, Colorado, 2003–2005: U.S. Geological 

Survey Scientific Investigations Report 2007–5225, 24 p.
iii

Contents

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

Introduction ....................................................................................................................................................1

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

Description of Study Area ...................................................................................................................2

Acknowledgments................................................................................................................................3

Historical Background .........................................................................................................................3

Study Methods ...............................................................................................................................................6

Data Collection .....................................................................................................................................7

Basin Characteristics and Interpretation of Land-Use Data................................................7

Stream-Reach Characteristics..................................................................................................7

Data Analysis................................................................................................................................................11

Stream Hydrology ...............................................................................................................................11

Habitat. ..................................................................................................................................................12

Water Chemistry .................................................................................................................................12

Resolution of Taxonomic Ambiguities .............................................................................................13

Relating Urban Hydrology, Habitat, and Water Chemistry to Fish and Invertebrate

Community Structure............................................................................................................13

Urban-Related Environmental Variables..................................................................................................13

Stream Hydrology ...............................................................................................................................14

Habitat. ..................................................................................................................................................14

Water Chemistry .................................................................................................................................15

Relating Urban-Related Environmental Variables with Patterns in Biological Community

Structure..........................................................................................................................................15

Fish Communities................................................................................................................................15

Invertebrate Communities.................................................................................................................17

Major Findings..............................................................................................................................................18

Summary........................................................................................................................................................19

References Cited..........................................................................................................................................20

Glossary.........................................................................................................................................................24
iv

Figures

1. Map showing locations of stream segments and sampling sites in the Fountain Creek 

basin, Colorado, 2003–2005. .......................................................................................................4

2. Conceptual model showing the primary urban-related environmental variables 

associated with stream ecology in the Fountain Creek basin, Colorado. .........................18

Tables

1. Description of sites and types of data collected in the Fountain Creek basin,

Colorado, 2003–2005.....................................................................................................................5

2. Basin and stream-reach habitat variables used to characterize selected sites in

the Fountain Creek basin, Colorado, 2003–2005 ......................................................................8

3. Coefficients used to convert land use to impervious surface coverage in the

Fountain Creek basin, Colorado, 2003–2005 ...........................................................................10

4. Water-chemistry variables used to characterize selected sites in the Fountain

Creek basin, Colorado, 2003–2005............................................................................................11

5. Hydrologic indices calculated to characterize the flow regimes from selected sites

in the Fountain Creek basin, Colorado, 2003–2005 ................................................................12

6. Correlation matrix showing Spearman’s rho values relating impervious surface

cover and eight environmental variables used in the exploratory multivariate

analysis (BIO-ENV procedure). ................................................................................................14

7. Correlation coefficients associated with the best subsets of urban-related

environmental variables describing biological community structure from the

exploratory multivariate analysis (BIO-ENV procedure)......................................................16
v

Conversion Factors and Datums

Multiply By To obtain

Length

inch (in) 2.54 x 100 centimeter (cm) 

inch (in) 2.54 x 101 millimeter (mm)

inch (in) 2.54 x 104 micrometer μm)

foot (ft) 3.048 x 10–1 meter (m)

mile (mi) 1.609 x 100 kilometer (km)

micrometer (μm) 1.0 x 102 centimeter (cm)

Flow rate

cubic foot per second (ft3/s) 2.832 x 10–2 cubic meter per second (m3/s)

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

°F=(1.8×°C)+32

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

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.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).
vi

Abbreviations

BIO-ENV exploratory multivariate analysis

CDOW Colorado Division of Wildlife

CDPHE Colorado Department of Public Health and Environment

DC direct current

HIs hydrologic indices

HIT Hydrologic Index Tool

IDAS Invertebrate Data Analysis System

ISC impervious surface coverage

MDS nonmetric multidimensional scaling

NAWQA National Water-Quality Assessment Program

NWIS National Water Information System

NWQL National Water Quality Laboratory

PAHs polycyclic aromatic hydrocarbons

PRIMER Plymouth Routines in Multivariate Ecological Research

QMH qualitative multihabitat

RBP Rapid Bioassessment Protocols

RTH richest targeted habitat

SPMDs semipermeable membrane devices

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

WWTF wastewater-treatment facility
Abstract

In 2003, the U.S. Geological Survey, in cooperation with 

Colorado Springs City Engineering began a study to evaluate the influence of urbanization on stream ecosystems. To 

accomplish this task, invertebrate, fish, stream discharge, habitat, water-chemistry, and land-use data were collected from 

13 sites in the Fountain Creek basin from 2003 to 2005. The 

Hydrologic Index Tool was used to calculate hydrologic indices known to be related to urbanization. Response of stream 

hydrology to urbanization was evident among hydrologic 

variables that described stormflow. These indices included one 

measurement of high-flow magnitude, two measurements of 

high-flow frequency, and one measurement of stream flashiness. Habitat and selected nonstormflow water chemistry were 

characterized at each site. Land-use data were converted to 

estimates of impervious surface cover and used as the measure 

of urbanization annually. Correlation analysis (Spearman’s 

rho) was used to identify a suite of nonredundant streamflow, 

habitat, and water-chemistry variables that were strongly 

associated (rho > 0.6) with impervious surface cover but not 

strongly related to elevation (rho < 0.60).

An exploratory multivariate analysis (BIO-ENV, 

PRIMER ver 6.1, Plymouth, UK) was used to create subsets 

of eight urban-related environmental variables that described 

patterns in biological community structure. The strongest and 

most parsimonious subset of variables describing patterns in 

invertebrate community structure included high flood pulse 

count, lower bank capacity, and nutrients. Several other combinations of environmental variables resulted in competing 

subsets, but these subsets always included the three variables 

found in the most parsimonious list. 

This study found that patterns in invertebrate community 

structure from 2003 to 2005 in the Fountain Creek basin were 

associated with a variety of environmental characteristics 

influenced by urbanization. These patterns were explained 

by a combination of hydrologic, habitat, and water-chemistry 

variables. Fish community structure showed weaker links 

between urban-related environmental variables and biological patterns. A conceptual model was developed that showed 

the influence of urban-related environmental variables and 

their relation to fish and invertebrate assemblages. This model 

should prove helpful in guiding future studies on the impacts 

of urbanization on aquatic systems. Long-term monitoring 

efforts may be needed in other drainages along the Front 

Range of Colorado to link urban-related variables to aquatic 

communities in transition zone streams. 

Introduction 

Anthropogenic influences on the landscape occur worldwide and nowhere else is this more apparent than in the urban 

environment. Land-use changes accompanying urbanization 

are often linked to the degradation of stream ecosystems 

(Klein, 1979; Kennen, 1999; Paul and Meyer, 2001; Roy and 

others, 2003; Roy and others, 2005). Recently, the U.S. Environmental Protection Agency (USEPA) reported that urbanization was ranked third as a leading source of river impairment 

behind agriculture and hydrologic modification (U.S. Environmental Protection Agency, 2000). 

As urban areas develop, land-cover characteristics 

change and the amount of impervious surface coverage (ISC) 

increases. Such changes alter surface- and ground-water 

hydrology, resulting in increased runoff rates, decreased 

base flow, increased peak flows (Knighton, 1998; Dunne and 

Leopold, 1978; Leopold 1968), reduced infiltration rates, and 

pollutant-filtering efficiency (Riordan and others, 1978). In 

some situations, reductions in base flow can be offset by lawn 

irrigation, leaky infrastructure, and discharge from wastewatertreatment facilities (WWTF) (Hirsch and others, 1990; Roy 

and others, 2005). 

Increased frequency of flooding and peak discharge during rain events can cause severe erosion of a stream channel. 

Flooding, erosion, and stream bank instability deteriorate the 

natural values of streams and damage adjacent properties. 

Urban-Related Environmental Variables and Their Relation 

with Patterns in Biological Community Structure in the 

Fountain Creek Basin, Colorado, 2003–2005

By Robert E. Zuellig, James F. Bruce, Erin E. Evans, and Robert W. Stogner

 
In an attempt to protect property owners from flooding or 

poor drainage structural solutions are often used that confine, 

deepen and straighten stream channels (Klein, 1979; Dunne 

and Leopold 1978). These structures can decrease stream 

habitat complexity by destroying pool-and-riffle sequences, 

removing woody debris and riparian vegetation, and altering 

particle-size structure of bottom substrate (Burton and Pitt, 

2002; Pizzuto and others, 2000). Changes in stream hydrology, 

water chemistry, and physical habitat associated with changes 

in ISC often results in altered aquatic communities and 

biological processes (Roy and others, 2005; Roy and others, 

2003; Paul and Meyer, 2001). 

Increased urban runoff can lead to substantial changes 

in water quality from point and nonpoint sources (Sprague 

and others, 2006; Edelmann and others, 2002; Pitt and others, 

1995; House and others, 1993). Typical urban contaminants 

that pollute streams include nutrients, metals, bacteria, sediments, pesticides, hydrocarbons, analgesics, antibiotics, and 

endocrine disruptors (Pitt and others, 1995; House and others, 

1993; Kolpin and others, 2002). Because of decreased base 

flow, concentrations of some of these contaminants also may 

be higher during dry periods due to decreased dilution capacity (Burton and Pitt, 2002). Many of these contaminants have 

been associated with undesirable changes in aquatic communities (for example, see Waters, 1995; LeBlanc and others, 

1997; McMurry and others, 1998; Fitzgerald and others, 1999; 

Burton and Pitt, 2002; Thorpe and others, 2001; Schreurs and 

others, 2004). 

The influence of urbanization on stream discharge 

(streamflow), habitat, and aquatic communities is an emerging issue of local, state, and national importance. Although 

consistent responses in urban streams have been identified 

in the eastern part of the United States, few studies have 

been conducted in the semi-arid western states. Rapid urban 

growth and development are occurring in many of these states, 

including along the Front Range of Colorado. To address these 

concerns, the U.S. Geological Survey (USGS), in cooperation with Colorado Springs City Engineering, began a study 

of the Fountain Creek basin in 2003 to evaluate the influence 

of urbanization on stream hydrology, habitat, water chemistry, 

and aquatic communities. 

Purpose and Scope

This report evaluates how urbanization (measured as 

impervious surface coverage, ISC) and hydrology, habitat, 

and water chemistry relate to changes in fish and benthic 

invertebrate community structure at 13 streamflow-gaging 

stations (fig. 1) in the Fountain Creek basin from 2003 to 

2005. The original scope of this study was to evaluate biological responses influenced by ISC (urbanization) between 

and within several different site types grouped by similarities 

in environmental characteristics, such as discharge, percent 

ISC, geomorphology, streambed substrate, canopy opening, 

and spatial relation to the Las Vegas St. WWTF in Colorado Springs (fig. 1). However, precipitation data needed to 

simulate streamflow at 11 additional sites were not available as intended. Consequently, the scope of this report is 

limited to evaluating data for the 13 sites with permanent 

streamflow gages (fig. 1), resulting in a data set that is highly 

auto-correlated in space and time and has limited statistical 

analysis options. Therefore, results of this study were interpreted with caution.

Habitat, fish, and invertebrate data evaluated in this report 

are available upon request from the USGS Colorado Water 

Science Center (Pueblo, Colorado office). Stream discharge 

and water- chemistry data can be obtained on the Web at 

http://waterdata.usgs.gov/co/nwis (search by USGS station 

number, fig. 1; table 1).

Description of Study Area

The Fountain Creek basin (fig. 1) has a drainage area of 

about 926 mi2, and elevation ranges from about 4,700 ft at the 

confluence with the Arkansas River to 14,109 ft at the summit 

of Pikes Peak. There are two major physiographic landforms 

within the area—the Front Range and the Colorado Piedmont 

(Hansen and Crosby, 1982), which correspond to two Level 

III ecoregions—the Southern Rockies and the Southwestern 

Tablelands (Omernik, 1987). The Front Range, which comprises the western one-third of the study area, is underlain by 

granite. Soils in this area are well drained and occur on steep 

slopes (Larsen, 1981; von Guerard, 1989). The Colorado 

Piedmont, which comprises the remaining eastern two-thirds 

of the area, abuts the base of the Rampart Range, which is a 

sub-range of the Front Range, and is underlain by sandstone, 

shale, alluvial, and windblown deposits. Soils in this area are 

generally sandy and well drained with more gentle slopes 

(Larsen, 1981; von Guerard, 1989). The soils and geologic formations in the Colorado Piedmont are readily erodible. Larsen 

(1981) and von Guerard (1989) thoroughly describe the soils 

and geology of the study area. 

Fountain and Monument Creeks are the two main streams 

within the study area and are located in the transition of the 

two distinctive physiographic landforms. To facilitate the 

general physical description of Fountain Creek, three segments 

were defined: the upper, middle, and lower segments (fig. 1).

The upper segment begins at the headwaters near Woodland Park and continues downstream to the confluence with 

Monument Creek. Fountain Creek is an intermittent stream 

for approximately the first half of the upper segment and it 

becomes a perennial stream near the town of Green Mountain 

Falls. Fountain Creek flows southeastward through a deeply 

incised canyon through Manitou Springs to the confluence 

with Monument Creek. The stream channel upstream from 

Manitou Springs meanders little due to the constraints of a 

major highway, is characterized by riffles and pools, and has 

bed material that ranges from sand and gravels to cobbles 

and boulders. From Manitou Springs, Fountain Creek flows 

through alluvial terraces into a wide alluvial valley; the channel meanders less due to intermittent channelization, consists 

2 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
of pools, riffles, and runs, and has bed material that is predominantly sand, gravel, and cobble. 

The middle segment begins at the confluence of Monument Creek and continues downstream to USGS station 

number 07105800 (fig. 1). In the middle segment, the channel becomes braided, stream segments have been channelized, streamflow is dominated by runs with few pools, and 

the streambanks are intermittently lined with concrete, and 

other manmade materials. The bed material is variable; some 

stream reaches have predominantly cobble substrate, some are 

scoured to bedrock, and others are a mixture of sand, gravel, 

and cobble. 

The lower segment of Fountain Creek begins immediately 

downstream from USGS station number 07105800 (fig. 1) and 

continues to the confluence of the Arkansas River in Pueblo, 

Colorado. The channel in the lower segment meanders more, 

is wider, and is often braided. Streamflow is composed almost 

exclusively of runs. Several reaches have been channelized for 

irrigation and transportation purposes. The streambed material 

in this segment is almost exclusively composed of sand and 

gravel. Large woody debris piles accumulate infrequently in 

the channel and along the banks. However, these debris piles 

are not stable and frequently are moved or buried during high 

flows. Periods of little or no flow were not unusual along the 

lower segment prior to about 1980, especially during the latesummer irrigation season (Stogner, 2000).

Monument Creek, the main tributary to Fountain Creek, 

is a perennial stream that originates in the Rampart Range and 

flows eastward toward Palmer Lake, then south to Colorado 

Springs. Upstream from the confluence with Cottonwood 

Creek, Monument Creek is meandering, has pools, riffles, 

and runs, and has bed material consisting of sand, gravel, and 

cobble. Downstream from the confluence with Cottonwood 

Creek, the channel becomes braided, sand and small gravel 

compose the streambed along with manmade materials, the 

stream banks are intermittently lined with concrete, and extensive channelization has occurred. The braided channel conditions occur intermittently throughout the remaining length of 

channel with few areas of pools and riffles.

Acknowledgments

 Gary Dowler, Dan Frankowski, and Londell Ackley of 

the Colorado Division of Wildlife (CDOW) provided backpack electrofishing equipment and contributed greatly to the 

fish-sampling efforts. Thanks to Lisa Ross, Colorado Springs 

City Engineering, for her support of the program. Thanks also 

to Colorado Springs Utilities for their support. Gary Dowler 

and Nicole Vieira (CDOW) provided a thoughtful review and 

comments that improved the report. Thanks to Joel Mackey, 

Colorado Springs City Engineering, for providing land-use 

data. The authors also thank those who assisted with the data 

collection, including USGS employees Wade J. Walker, Mark 

Salay, John Ragulsky, and all USGS hydrographers that collected, compiled, and analyzed streamflow measurement data.

Historical Background

Streamflow and Habitat. By the mid-1800s, human 

alteration of stream habitats, natural flow regimes, and aquatic 

biota had occurred in streams and tributaries near the transition from plains to mountains along the Front Range of 

Colorado (Fausch and Bestgen, 1997 and citations within). 

Although never formally defined, this transition zone likely 

varies in width depending on local topography. It is thought to 

be approximately 20 miles wide and situated between plains 

and montane habitats at elevations usually less than 7,000 ft 

and greater than 4,000 ft (Fausch and Bestgen, 1997; Nesler 

and others, 1999). Historical accounts (Fausch and Bestgen, 

1997 and citation within) from the 1840s of the physical habitat attributes from transition zone and plains streams of eastern 

Colorado indicate that several changes had occurred with 

minimal documentation. Chief among the physical habitat 

modifications to plains streams in Colorado during this time 

was channel widening, which was exacerbated by drought in 

the 1930s, increased sinuosity and pool frequency, and riparian encroachment by woody vegetation (Fausch and Bestgen, 

1997 and citations within). In addition, changes to transition 

zone streams included a streambed substrate from cobble and 

gravel to less coarse particles and increased turbidity (Fausch 

and Bestgen, 1997). 

Documented hydrologic modifications to plains and 

transition zone streams began as early as 1840 with the construction of small ditches for agriculture and mining (Fausch 

and Bestgen, 1997 and citations within). Subsequently, 

large canals were constructed as the need for irrigation 

grew (1860–1885), and later (1885–1940s) large mainstem 

reservoirs were constructed to store snowmelt runoff and 

control flooding. The most recent hydrologic modifications 

(1940s-present) include reservoir construction that provided 

additional water for agriculture and municipal water use, and 

ground-water withdrawals that has decreased base flow (Cross 

and Moss, 1987). In addition, transmountain water diversions, 

expansion of wastewater-treatment facility (WWTF) discharge, and urbanization have resulted in increased base flow.

The modifications briefly described above have changed 

the hydrologic and physical characteristics of plains streams 

and transition zone streams in Colorado. In snowmelt-driven 

systems, maximum flows related to snowmelt runoff have 

been reduced in many plains streams whereas base flow has 

increased in basins with mainstem reservoirs (Nadler and 

Schumm, 1981). However, in some plains streams groundwater withdrawals, irrigation canals, and off channel ponds 

have decreased base flow and in some instances completely 

dewatered channels (Cross and Moss, 1987). In Fountain 

Creek, base flow above the Las Vegas St. WWTF in Colorado Springs (fig. 1) is primarily sustained by ground-water 

discharge, but downstream from the WWTF, base flow is 

composed predominantly of WWTF discharge (Edelmann and 

others, 2002). A substantial increase in base flow was evident in the lower reaches of Fountain Creek after 1980 when 

trans-mountain return flows were not available for irrigation 

Introduction 3
PUEBLO

WOODLAND PARK

PALMER LAKE

MONUMENT

MANITOU SPRINGS

GREEN MOUNTAIN FALLS

Monument Creek

Bear Creek

Cottonwood Creek

J

mi my

Camp Creek

Fountain Creek

Pikes Peak

07103970

07106500

07106300

07106000

07105900

07105800

07105530

07105500 07105000

07104905

07103990

07103980

07103700

105° 104°45' 104°30'

39°

38°45'

38°30'

38°15'

Fort Carson

Military Reservation

Las Vegas

Street Wastewater

Treatment Facility

US Air Force 

Academy

Peterson Air 

Force Base

0 2.5 5 Miles

0 2.5 5 Kilometers

Base from U.S. Geological Survey 

Albers Equal-area projection

Standard parallels 37o

 30' N and 40o 30' N

Central meridian 105o

 30' W

COLORADO

Denver

Study Area

EXPLANATION

Ecoregion

Southern Rockies

Southwestern Tablelands

Military base or reservation

Municipal area

Upper Fountain Creek

Middle Fountain Creek

Lower Fountain Creek

Sampling site and number 07103985

Front Range

Rampart Range

Colorado Piedmont

COLORADO SPRINGS

Arkansas River

Arkansas River

Basin boundary

(see table 1)

Figure 1. Map showing locations of stream segments and sampling sites in the Fountain Creek basin, Colorado, 2003–2005. 

4 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
Table 1. Description of sites and types of data collected in the Fountain Creek basin, Colorado, 2003–2005.

[USGS, U.S. Geological Survey; ID, identification; NAVD 88, North American Vertical Datum of 1988; ft, feet; mi2, square miles; ISC, impervious 

surface cover; X, collected; --, not collected] 

USGS 

station 

number1

Station name Site 

ID

Elevation 

NAVD 88

(ft)

Drainage 

area

(mi2)

Mean 

percent 

ISC

Streamflow 

discharge

Habitat Chemistry Fish Invertebrates

07103700 Fountain Creek near 

Colorado Springs, 

Colo.

FC1 6,110 103 8.9 X X X X X

07103970 Monument Creek 

above Woodmen 

Road at Colorado 

Springs, Colo.

MC1 6,270 181 11 X X X X X

07103980 Cottonwood Creek at 

Woodmen Road near 

Colorado Springs, 

Colo.

CC1 6,680 10.3 14.4 X X X -- X

07103990 Cottonwood Creek at 

Mouth at Pikeview, 

Colo.

CC2 6,265 18.7 23 X X X -- X

07104905 Monument Creek at 

Bijou Street at Colorado Springs, Colo.

MC2 5,980 235 14.2 X X X X X

07105000 Bear Creek near Colorado Springs, Colo.BC 6,520 6.89 2.3 X X X -- X

07105500 Fountain Creek at 

Colorado Springs, 

Colo.

FC2 5,900 392 12.4 X X X X X

07105530 Fountain Creek below 

Janitell Road below 

Colorado Springs, 

Colo.

FC3 5,840 413 14.1 X X X X X

07105800 Fountain Creek at 

Security, Colo.

FC4 5,640 495 15.7 X X X X X

07105900 Jimmy Camp Creek at 

Fountain, Colo.

JC 5,530 65.6 8.5 X X X -- X

07106000 Fountain Creek near 

Fountain, Colo.

FC5 5,355 681 14.9 X X X X X

07106300 Fountain Creek near 

Pinon, Colo.

FC6 4,990 849 12.5 X X X X X

07106500 Fountain Creek at 

Pueblo, Colo.

FC7 4,705 926 12 X X X X X

1

See figure 1.

Introduction 5
withdrawals (Stogner, 2000). Additionally, some historically 

ephemeral tributaries to Monument and Fountain Creeks may 

have become perennial with small base flow (Edelmann and 

others, 2002). 

Fish Communities. Prior to 1900, fish had been collected from only 12 sites in the plains portion of Colorado 

(Fausch and Bestgen, 1997). Seven of these collections were 

from transition zone streams in the Arkansas River drainage near the cities of Canon City (about 33 mi northwest of 

Pueblo), Colorado Springs, and Pueblo. The other five collections were from transition zone and montane sites near Denver 

in the South Platte basin. Basin-wide fish surveys in the plains 

portion of the Arkansas River drainage, including Fountain 

Creek, did not occur until after 1958 (Fausch and Bestgen, 

1997). Later, two comprehensive surveys of the plains portion 

of the Arkansas River basin were conducted by the Colorado 

Division of Wildlife (CDOW) (Loeffler and others, 1982; 

Nesler and others, 1999). Nesler and others (1999) made comparisons and described trends between the Loeffler and others 

(1982) and Nesler and others (1999) surveys. No differences 

in the number of native fish present were found in the Arkansas River basin between the two inventories. Although no 

differences in native fish presence were found between these 

inventories, the data allowed only for basin-wide assessments 

for the entire Arkansas River drainage. Such coarse-level comparisons provided little information regarding local changes 

in fish community dynamics that have likely occurred in 

plains streams and transition zone streams at smaller scales as 

changes in land cover associated with urbanization, hydrology, 

and habitat occurred. 

Because the distribution of fishes in the Arkansas River 

basin was not documented until well after major changes in 

hydrology and habitat had occurred, how current patterns of 

fish distribution are related to historical conditions cannot 

be interpreted definitively. Fausch and Bestgen (1997) used 

literature accounts, museum records, and unpublished data 

to determine that there are likely 20 fish species native to the 

Arkansas River basin in Colorado. Of these 20 native species 

(see Table 6.1 in Fausch and Bestgen, 1997) a conservative 

estimate of 16 species could have occurred in the plains portion of the transition zone of the Fountain Creek basin. Of the 

four species not likely found in these segments of Fountain 

Creek, three are mainly associated with big rivers: plains minnow (Hybognathus placitus), speckled chub (Macrohybopsis

aestivalis), and Arkansas River shiner (Notropis girardi). The 

fourth native species, the greenback cutthroat trout (Oncorhynchus clarki stomias), is a cold-water species and likely never 

persisted in the warmer waters of lower Fountain Creek.

During the two most recent inventories, Loeffler and 

others (1982) collected 11 native species while Nesler and 

others (1999) collected only 9 from Fountain Creek sites; 

however, sampling efficiency information associated with 

these data-collection efforts is unavailable to make a comparative assessment. Currently (2007), there are three state-listed 

and one federally-listed species in the Fountain Creek basin: 

southern redbelly dace (Phoxinus erythrogaster) which is state 

endangered, Arkansas darter (Etheostoma cragini) which is 

state threatened, flathead chub (Platygobio gracilis) which is a 

state species of concern, and greenback cutthroat trout which 

is federally threatened. 

Invertebrate Communities. To date, no systematic 

survey of the Colorado aquatic insect fauna has focused 

on plains streams. There are only sporadic early records of 

aquatic invertebrates from plains streams, mostly from the 

South Platte River basin where several species apparently 

have been extirpated locally (Edmunds and McCafferty, 1984; 

McCafferty and others, 1993; Cordeiro, 1999; Kondratieff and 

Baumann, 2002, Zuellig and others, 2006). 

Although there is little information about historic or 

current aquatic invertebrate species distribution in the Fountain Creek basin and most other plains streams of Colorado, 

there have been a few biomonitoring studies conducted in the 

Fountain Creek basin since the late 1980s. For example, von 

Guerard (1989) studied the effects of sediment-transport on 

aquatic invertebrates and sediment-transport characteristics in 

the Fountain Creek basin. In that study it was determined that 

mayflies, stoneflies, and caddisflies were more abundant at 

sites where the streambed was not influenced by aggradation 

and deposition. Additionally, median diameter of streambed 

material and flooding prior to invertebrate sampling explained 

most of the variation in invertebrate densities (at the genus 

or family level taxonomy). Additionally, von Guerard (1989) 

found that small to moderate streamflows were capable of 

transporting the majority of all streambed particle-size classes 

in Fountain and Monument Creeks. Bruce (2002) also found 

that substrate particle-size accounted for most of the variation 

in invertebrate community structure among sites in the Fountain Creek basin. 

Study Methods

Thirteen sites were selected to represent varying environmental conditions found in the Fountain Creek basin to 

investigate the overall influence of urbanization (that is, ISC) 

on stream hydrology and its effect on habitat, water chemistry, and biological communities (fig. 1). Environmental (ISC 

and habitat) and biological (fish and invertebrates) data were 

collected once annually at respective sites from 2003 to 2005 

(table 1). Streamflow was measured continuously at these 

sites, and selected water chemistry was collected 3-6 times 

annually during the study period. Each site was equipped with 

telemetry for the processing of daily real-time streamflow 

data. All data types collected at each site are listed in table 1, 

and can be requested from the USGS Colorado Water Science 

Center (Pueblo, Colorado office). Data were analyzed using 

descriptive statistics, such as Spearman rank correlation and 

exploratory nonparametric multivariate routines. Results of 

this study can help direct approaches of future investigations 

in the Fountain Creek basin. 

6 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
Data Collection 

Basin Characteristics and Interpretation of

Land-Use Data

For each site, 10 basin characteristics were derived from 

data consisting of mapped polygons of land use provided by 

the city of Colorado Springs (table 2). USGS topographic 

maps (U.S. Geological Survey, 1974) were used to estimate 

land uses and their corresponding area for approximately 

30 percent of the total area of the lower segment of Fountain Creek because the city of Colorado Springs data did not 

include the entire Fountain Creek basin. These data provide 

information on the upstream influences and hydrologic constraints at a site. Additionally, land use and ISC were estimated annually for each site. 

Land uses in the Fountain Creek basin include undeveloped land, agriculture, military reservations and airports, 

residential, commercial, industrial, and streets and easements. 

Estimates of ISC associated with different land uses were 

derived by applying coefficients to the summed area of the 

various land uses from the mapped polygons and interpolated 

from the USGS maps. The coefficients were adapted from 

Arnold and Gibbons (1996) and Pikes Peak Area Council of 

Governments (2005). The distribution of coefficients is listed 

in table 3. 

Stream-Reach Characteristics

Stream hydrology, habitat, selected water chemistry, and 

aquatic community structure were quantified at each site using 

established protocols. Methods used to collect these data are 

briefly described below. 

Hydrology. Instantaneous stream discharge (ft3/s) was 

measured and mean daily stream discharge was computed 

in accordance with standard USGS procedures described by 

Rantz and others (1982). Measurements of instantaneous 

stream discharge were made throughout the study period in 

the vicinity of the USGS streamgages at cross-sections that 

had the most even distribution of streamflow. These measurements of stream discharge were used to develop site-specific 

stage-discharge relations (rating curves) that were then used 

to compute continuous discharge data from the stage record 

associated with the 13 USGS surface-water gages. Mean 

daily discharge was acquired from USGS streamgage records 

(Crowfoot and others, 2003–2005). 

Habitat. At each site, 33 quantitative stream-reach characteristics (table 2) were measured using standardized USGS 

procedures (Meador and others, 1993) after biological sampling each year. In brief, reach length was defined as 20 times 

the mean wetted width (range 100 to 300 m [328 to 984 ft]). 

The length of each geomorphic channel unit (run, riffle, pool) 

was measured, and a pebble count at approximately 100 points 

along the reach was used to characterize three streambed and 

bank substrate compositions (Wolman, 1954) (table 2). Measurements of instream habitat were made along six equally 

spaced transects perpendicular to streamflow along each reach. 

At each transect, wetted channel width, streambed width, 

bankfull channel width, bank angle and height, stream depth, 

and current velocity were measured. Additionally, embeddedness was estimated along each transect. Froude number 

was calculated for each reach using stream depth and current 

velocity measurements. Riparian and bank vegetation characteristics as well as canopy opening also were recorded. 

Twelve qualitative habitat variables (table 2) were evaluated during the invertebrate sampling site visits using the rapid 

bioassessment protocols (RBP) developed by Barbour and 

others (1997). In general, RBP attributes are separated into 

three categories: primary, secondary, and tertiary. The primary 

attributes (scored 0-20) characterize instream habitat and 

likely have the greatest direct influence on biological community structure. Secondary attributes (scored 0-15) characterize channel morphology, and tertiary attributes (scored 0-10) 

characterize bank structure and riparian areas. For each reach, 

the scores for each attribute were summed to derive a single 

numeric RBP value ranging from 0 to180 (unitless).

Water Chemistry. Routine water-chemistry samples 

during nonstormflow conditions were collected in June and 

September, bracketing the biological sampling using standard 

equipment with width- and depth-integrating techniques. At 

the time of sampling, field measurements were made for dissolved oxygen, pH, specific conductance, and water temperature (table 4). All samples were collected, processed, and 

preserved in the field according to standard methods described 

in the National Field Manual by the U.S. Geological Survey 

(1997–present). Constituents included dissolved ammonia, 

dissolved nitrite plus nitrate, dissolved orthophosphate, total 

phosphorus, Escherichia coli, fecal coliform bacteria, and suspended sediment (table 4). Nutrient samples were analyzed at 

the USGS National Water Quality Laboratory (NWQL, Lakewood, Colo.) as described by Fishman (1993). Suspendedsediment samples were collected as described by Edwards and 

Glysson (1988) and analyzed at the USGS Iowa Water Science 

Center Sediment Laboratory using methods described by Guy 

(1969). Escherichia coli and fecal coliform bacteria samples 

were processed, incubated, and counted in the Colorado Water 

Science Center Pueblo office laboratory as described by 

the U.S. Geological Survey (1997-present). Mau and others 

(2007) provide detailed information concerning water-chemistry collection methods, interpretation of water-chemistry data, 

as well as information concerning quality assurance/quality 

control of water-chemistry data collected during the study 

period. 

Fish. Fish community data were collected at main stem 

sites along Fountain Creek in mid-September during baseflow conditions (table 1). All sites were wadable at the time 

of sampling. Each reach was electrofished in an upstream 

direction with a single pass (Pusey and others, 1998) using 

Smith-Root pulsed DC backpack electroshockers (model 12B 

POW and model 15D POW). A concerted effort was made to 

sample all available habitats along each reach. The length of 

Study Methods 7
Table 2. Basin and stream-reach habitat variables used to characterize selected sites in the Fountain Creek basin, Colorado, 

2003–2005.

[mi2, square miles; mi, miles; %, percent; ft, feet; NAVD 88, North American Vertical Datum of 1988; m, meters; ft/s, feet per second; mm, millimeters; RBP, 

rapid bioassessment protocols; >, greater than]

Code Habitat variable and unit

Basin characteristics

DAREA1 drainage area (mi2)

VLENGTH valley length (mi)

pctAG agriculture land use (% of drainage basin area)

pctCOM commercial land use (% of drainage basin area)

pctIND1 industrial land use (% of drainage basin area)

pctMIL military reservation and airports (% of drainage basin area)

pctRES residential land use (% of drainage basin area)

pctSTR streets and easements (% of drainage basin area)

pctUND undeveloped land (% of drainage basin area)

ISC impervious surface cover (% of drainage basin area)

Stream-reach characteristics

Quantitative variables

ELEV elevation (ft NAVD 88)

CHANMOD channel modification (categorical variable describing degree of channel disruption from natural state)

REALENGTH1 reach length (m)

WATSURGRAD1 water surface gradient (reach water surface gradient (dimensionless)

pctRIF % of reach length composed of riffle habitat (%)

pctRUN % of reach length composed of run habitat (%)

pctPOOL % of reach length composed of pool habitat (%)

WCW1 wetted channel width (m)

BEDW1 streambed width (m)

BANKFULW1 bankfull channel width (m)

BANKANG bank angle (degrees)

BANKHT bank height (m)

BANKVEG bank vegetative cover (%)

BANKGRASS % of bank vegetation composed of grass (%) 

BANKFORB % of bank vegetation composed of forbs (%) 

BANKSHRUB % of bank vegetation composed of shrubs (%) 

BANKTREE % of bank vegetation composed of trees (%) 

RIPVEG riparian vegetative cover (%)

RIPGRASS % of riparian vegetation composed of grass (%) 

RIPFORB % of riparian vegetation composed of forbs (%) 

RIPSHRUB % of riparian vegetation composed of shrubs (%) 

RIPTREE % of riparian vegetation composed of trees (%) 

8 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
Code Habitat variable and unit

Stream-reach characteristics

Quantitative variables

TOTALSUN total sun exposure on water surface (degrees)

DEPTH1 depth at point velocity site (ft)

CVEL1 current velocity at point velocity site (ft/s)

FROUDE Froude number (current velocity divided by [{gravitational acceleration multiplied by depth of water}

 exponent0.5] dimensionless)

EMBEDD embeddedness of substrate at point velocity site (%)

pctSILT % occurrence of silt from Wolman pebble count (%)

pctSAND % occurrence of sand from Wolman pebble count (%)

pctGRAVEL % occurrence of gravel from Wolman pebble count (%)

pctCOBB % occurrence of cobble from Wolman pebble count (%)

pctBOULD % occurrence of boulder from Wolman pebble count (%)

pctBEDROK % occurrence of bedrock from Wolman pebble count (%)

Streambed and bank substrate composition

D20 20th percentile grain size derived from Wolman pebble count data (mm)

D50 median grain size derived from Wolman pebble count data (mm)

D80 50th percentile grain size derived from Wolman pebble count data (mm)

Qualitative variables

SUB streambed substrate (primary RBP variable)

EMBED embeddedness (primary RBP variable)

VELDEPREG velocity depth regime (primary RBP variable)

CANP canopy cover (primary RBP variable)

CHANALT1 channel alteration (secondary RBP variable)

SCODEP bottom scour and deposition (secondary RBP variable)

PRRB pool/riffle, run/bend ratio (secondary RBP variable)

LBCAP lower bank channel capacity (secondary RBP variable)

UBSTAB upper bank stability (tertiary RBP variable)

BVEGCOND bank vegetation condition (tertiary RBP variable)

STRCOV streamside cover (tertiary RBP variable) 

RIPWIDTH riparian vegetative zone width (tertiary RBP variable)

RBPSCORE RBP score (sum of individual RBP variable scores)

1

Spearman’s rho between variable and elevation > 0.6.

Table 2. Basin and stream-reach habitat variables used to characterize selected sites in the Fountain Creek basin, Colorado, 

2003–2005.—Continued

[mi2, square miles; mi, miles; %, percent; ft, feet; NAVD 88, North American Vertical Datum of 1988; m, meters; ft/s, feet per second; mm, millimeters; RBP, 

rapid bioassessment protocols; >, greater than]

Study Methods 9
number of steps from the downstream boundary for the three 

sample locations within the length of the selected RTH (riffle 

or run). Randomly selected points were rejected if the point 

was outside the boundary of the RTH, and were replaced with 

alternative randomly generated points. If a sample point could 

not be sampled due to the substrate exceeding the limit of the 

sampler, the point was moved laterally or upstream one step. 

Attempts were made to sample the same habitat type at each 

site every year, but in Fountain Creek runs and riffles are not 

spatially stable due to streambed alteration caused by naturally 

shifting sand, stormflows, and episodic utility construction 

within the channel. Samples were collected in a downstream 

to upstream direction. The Hess sampler was pushed firmly 

into the streambed and the substrate was mixed to dislodge 

invertebrates. When present, cobbles were scrubbed inside the 

sampler to further remove clinging invertebrates and inspected 

for remaining invertebrates. The remaining substrate within 

the sampler was stirred by hand or a sturdy metal utensil to a 

depth of approximately 0.10 m to dislodge invertebrates from 

smaller substrate and those dwelling within the substrate. 

The sampler was rinsed with stream water between sample 

collections to minimize cross-contamination between samples 

the reach sampled ranged from 42 to 300 m (138 to 984 ft). 

After capture, fish were maintained in aerated live wells. All 

fish were identified, enumerated, and measured (total length) 

in the field, tallied in the nearest 2-cm (0.79 inch) length class, 

observed for anomalies, and released. Species-level field identification was problematic for only small young-of-the-year 

fish (< 20 mm), but these accounted for less than 0.1 percent 

of the total catch. Voucher specimens of anomalous fish 

were retained by the CDOW. The CDOW also submitted fish 

from different trophic guilds at selected sites to the Colorado 

Department of Public Health and Environment (CDPHE) for 

tissue analysis. 

Invertebrates. Invertebrates were sampled each year during base-flow conditions in October several weeks after fish 

sampling. A Hess sampler (0.086 m2 or 0.923 ft2) equipped 

with 500-μm mesh was used to collect three replicate samples 

from the expected richest targeted habitat (RTH). The intent of 

this study was to use a sampling approach to sample consistent RTH (riffles) at all sites. However, when riffles were 

absent in a stream reach, runs with the coarsest substrate were 

sampled. A random numbers table was used to determine the 

Table 3. Coefficients used to convert land use to impervious surface coverage in the Fountain Creek basin, 

Colorado, 2003–2005.

Land use category Land use subcategory

Coefficient of 

imperviousness,

in percent1

Undeveloped land 2

Agriculture 4

Military reservations and airports 13

Residential 1/2- acre or larger lot 12

1/4- to 1/2- acre lot 21

1/8- to 1/4- acre lot 28

high density detatched housing 39

condominiums and apartment buildings 65

undefined housing 33

Commercial low impact office 20

schools 35

unimproved parking lots 60

neighborhood commercial 70

high density commercial 85

parking structures 98

Industrial office and light industrial park 35

warehouse 70

mining 85

Streets and easements utility easement and undefined streets 60

collector streets 85

arterial streets 98

1

 Arnold and Gibbons (1996) and Pikes Peak Area Council of Governments (2005).

10 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
and sites. In addition to RTH samples, a dip net equipped with 

500-μm mesh was used to collect a qualitative multihabitat 

(QMH) sample after the RTH samples had been collected. 

Organisms in QMH samples were collected from all available 

habitat types within the stream reach. QMH samples contained 

a considerable amount of debris that was reduced in the field 

by elutriating and sieving (500-μm mesh metal sieve) until 

sample volumes were approximately 500 mL (about 1 pint). 

Invertebrate samples were preserved in the field with 

either 95-percent ethanol or 10-percent buffered formalin, and 

stored until they could be delivered to the contract laboratory (Chadwick and Associates in Littleton, Colo., or Aquatic 

Associates in Ft. Collins, Colo.) for identification. Sample processing, taxa identification, and enumeration conformed to the 

protocols developed by Moulton and others (2000). A voucher 

collection was prepared and updated annually and verified by 

the USGS NWQL. The NWQL also evaluated sorting efficiency for 5 percent of the RTH samples, which was found 

acceptable. 

Data Analysis

Hydrologic indices that describe stormwater flows associated with urbanization (ISC) were evaluated to determine 

their association with habitat and water chemistry. These data 

were then combined to determine the subset of environmental 

variables that best described patterns in fish and invertebrate 

community structure. 

Correlation analysis (Spearman’s rho) and examination 

of scatter plots with loess smoothing was used to evaluate the 

strength and form of the associations within variable types 

and among variables. In addition, a p-value < 0.05 (95-percent 

confidence that the statistical test is valid) was used to reject 

the null hypothesis for all tests. Spearman’s rho, which is 

based on the ranks of the values, was used because this measure can account for nonlinear relations. Correlation analysis 

also was used to identify highly correlated variables (Spearman’s rho > 0.9) within each variable group (hydrologic, 

habitat, water chemistry), so that the list of variables could be 

reduced to relate to biological communities. 

Biological communities are highly correlated with elevation in Colorado streams (Ward, 1986; Rahel and Hubert, 

1991). To alleviate the influence of elevation in the analysis, 

environmental variables were removed if they were highly 

correlated with elevation (Spearman’s rho > 0.6). Minimizing the effects of elevation in the analysis should help clarify 

the influence of urban-related environmental variables on the 

structure of biological communities in the Fountain Creek 

basin. 

The exploratory multivariate BIO-ENV procedure was 

used as the final analysis to identify the best match between 

community structure and a subset of environmental variables 

associated with those samples. Finally, a conceptual model 

describing the relations between ISC, stormwater hydrology, 

habitat, water chemistry, and fish and invertebrate community structure was constructed to guide future aquatic monitoring efforts. Correlation analyses were conducted using 

S-Plus 2000 (Mathsoft, Inc., 2000), and the BIO-ENV routine 

was computed using PRIMER version 6.1 software, Plymouth 

Routines in Multivariate Ecological Research (Clarke and 

Warwick, 2001). 

Stream Hydrology

Mean daily and instantaneous peak streamflow from 

13 on-site USGS continuous streamgages were imported to the 

Hydrologic Index Tool (HIT) software (Henriksen and others, 

2006) to calculate hydrologic indices (HIs) that describe various aspects of streamflow. The HIT calculates 171 HIs that 

are distributed among the five major components of the flow 

regime: magnitude, frequency, duration, timing, and rate of 

change (Olden and Poff, 2003 and citations within). Because 

streamflow data were evaluated on a yearly basis, which effectively removed indices related to timing and periodicity, only 

132 of the 171 HIs could be calculated. Twenty-three of the 

132 HIs were selected for further analysis because they were 

expected to, or have been demonstrated in the literature to be, 

influenced by urbanization (Walsh and others, 2005) (table 5). 

Correlation analysis (Spearman’s rho) was used to reduce further the number of variables by removing redundant variables 

(rho > 0.9), and those related to elevation (rho > 0.6), and to 

relate the remaining variables to ISC (rho > 0.6). 

Table 4. Water-chemistry variables used to characterize 

selected sites in the Fountain Creek basin, Colorado, 2003–2005.

[/, per; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 

25 oC; oC, degrees Celsius; col/100 mL, colonies per 100 milliliters; mL, 

milliliters; >, greater than]

Code Water-quality variable and unit

DO dissolved oxygen (mg/L)

PH pH

SC1 specific conductance (μS/cm)

WT water temperature (oC)

DNH4 dissolved ammonia (mg/L as N)

DNO23 dissolved nitrite plus nitrate (mg/L as N)

DOP dissolved orthophosphate (mg/L as P)

TP total phosphorus (mg/L as P)

EC Escherichia coli (col/100 mL)

FC fecal coliform bacteria (col/100 mL)

SEDCONC suspended-sediment concentration (mg/L)

1

Spearman’s rho between variable and elevation > 0.6.

Data Analysis 11
Habitat

Habitat data were summarized as either relative percentages of reach length, as minimum, maximum, mean or 

median values, or as RBP scores (table 2). Correlation analysis 

(Spearman’s rho) was used to eliminate redundant variables 

(rho > 0.9), to remove those variables related to elevation (rho 

> 0.6), and to relate the remaining variables to ISC (rho > 0.6). 

Water Chemistry

Water chemistry can differ substantially between stormflow and nonstormflow conditions as well as spatially in the 

Fountain Creek basin (Edelmann and others, 2002; Mau and 

others, 2007). Both of these reports indicated that stormflow 

chemistry is highly variable. The scope of this study was not 

broad enough to fully characterize chemical conditions during 

stormflow conditions at all sites. As a result there were not 

enough stormflow chemistry samples collected to relate stormflow chemistry to biology in a meaningful way. Therefore, 

water chemistry during nonstormflow conditions was used to 

relate water chemistry to urbanization and biological communities in the Fountain Creek basin during 2003–2005. To meet 

these criteria, the National Water Information System (NWIS) 

database was queried to extract nonstormflow water-chemistry 

samples that corresponded to sites during 2003–2005. The 

hydrograph was further analyzed to ensure that the samples 

had not been misidentified, and were indeed collected during nonstormflow conditions. Data were summarized as 

maximums, minimums, means, medians, and coefficients of 

variation (table 3). Correlation analysis (Spearman’s rho) was 

used to eliminate redundant variables (rho > 0.9), to remove 

Table 5. Hydrologic indices calculated to characterize the flow regimes from selected sites in the Fountain Creek basin, Colorado, 

2003–2005.

[ft3/s, cubic feet per second; CV, coefficient of variation; /, per; mi2, square miles; <, less than or equal to; >, greater than or equal to]

Flow regime Code Hydrologic variable description Unit

Magnitude MA21 Annual daily mean flow ft3/s

Magnitude MA3 Variability of annual daily mean flow (CV of annual daily mean flow) percent

Magnitude MA30 Variability of July daily mean flow (CV of July daily mean flow) percent

Magnitude ML7 Minimum July daily mean flow ft3/s

Magnitude ML14 Minimum annual daily mean flow ft3/s

Magnitude ML22 Drainage area normalized annual minimum flow ft3/s/mi2

Magnitude MH71 Maximum July daily mean flow ft3/s

Magnitude MH14 Annual maximum flow computed from monthly maximum flows , 

divided by the median annual flow dimensionless

Magnitude MH20 Drainage area normalized annual maximum daily mean flow ft3/s/mi2

Frequency FL1 Low flood pulse count (number of events < 25th percentile) number of events /year

Frequency FH1 High flood pulse count 1 (number of events > 75th percentile) number of events /year

Frequency FH3 High flood pulse count 2 (number of events > 75th percentile) number of events /year

Frequency FH5 Flood frequency (number of events > median) number of events /year

Duration DL1 Annual daily minimum flow ft3/s

Duration DL41 Annual 7-day mimimum average flow ft3/s

Duration DH11 Annual maximum daily flow ft3/s

Duration DH21 Annual maximum 3-day average flow ft3/s

Duration DH15 High flow pulse duration (duration for flow events > 75th percentile) days/year

Rate of change RA11 Rise rate (positive change in flow for consecutive days) ft3/s/day

Rate of change RA2 Variability of rise rate (CV of rise rate) percent

Rate of change RA31 Fall rate (negative change in flow for consecutive days) ft3/s/day

Rate of change RA41 Variability of fall rate (CV of fall rate) percent

Rate of change RA8 Number of reversals (number of days each year when the change in 

flow from consecutive days changes direction) days

1

Spearman’s rho between variable and elevation > 0.6.

12 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
those variables related to elevation (rho > 0.6), and to relate 

the remaining variables to ISC (rho > 0.6) as was done for the 

HIs and habitat.

Resolution of Taxonomic Ambiguities

Ambiguous taxa occur in biological data sets when 

closely related specimens are identified at different levels of 

taxonomic resolution. Distinguishing characteristics used to 

identify a taxon are generally described from mature specimens that may be absent in immature or damaged specimens. 

As a result, a sample may contain a group of individuals from 

the same genus (parent taxon), but not all can be identified to 

the species level (child taxon). Including ambiguous taxa in a 

data set can artificially increase richness or change similarities among samples collected from a series of sites. For the 

fish data, young-of-the-year could not be identified in the field 

so they were removed from the data set, thereby resolving all 

ambiguities because all other individuals were identified to 

species. Invertebrate ambiguities were resolved by comparing 

the abundances of ambiguous parent and children taxa using 

the Invertebrate Data Analysis System (IDAS) software (Cuffney, 2003). If the abundance of the parent was greater than the 

sum of the children’s abundances, the children were deleted 

and their abundances were added to the parent’s abundance. 

Otherwise, the children were retained and the parent was 

deleted. 

Relating Urban Hydrology, Habitat, and Water 

Chemistry to Fish and Invertebrate Community 

Structure

After data reduction as described above, the BIO-ENV 

procedure in the PRIMER version 6.1 software package 

(Clarke and Ainsworth, 1993) was used to link environmental 

variables to fish and invertebrate community structure. BIOENV is an exploratory nonparametric multivariate procedure 

that identifies the best match between community structure 

and a subset of environmental variables associated with those 

samples. The rationale is that if the environmental variables 

structuring a community were known, then samples having 

similar values for these environmental variables would have 

similar biological communities, and separate ordinations of 

the environmental variables and species composition would be 

similar (Clarke and Warwick, 2001). The match (Spearman’s 

rho) between the ordinations deteriorates if key environmental 

variables driving community structure are omitted or if environmental variables irrelevant to driving community structure 

are included. BIO-ENV calculates a Spearman’s rho value for 

ordinations of each possible combination of the environmental variables with an ordination of species composition. The 

subset of environmental variables with the best fitting match 

(highest rho value) to the species composition ordination is 

determined to be the best subset that describes community 

structure within the bounds of the data set. 

The underlying ordination method used in the BIO-ENV 

procedure is nonmetric multidimensional scaling (MDS). The 

main advantages of MDS over other ordination techniques is 

that MDS does not make any assumptions about the form of 

the data or the interrelations of the samples, and it has greater 

ability than other ordination methods to represent complex 

relations in low dimensional space (Clarke and Warwick, 

2001). Before data were analyzed, environmental variables 

were Log10 transformed and normalized by subtracting the 

mean from the observation and by dividing by the standard 

deviation. A fourth-root transformation was applied to RTH 

invertebrates and fish to down weight common taxa (Clarke 

and Warwick, 2001). The presence-absence data associated 

with invertebrate QMH samples were not transformed. After 

transformation, separate similarity matrices were calculated 

using Bray-Curtis similarity for biological data and Euclidean 

distance for the environmental data (Clarke and Warwick, 

2001). 

Results of the BIO-ENV routine and the data reduction 

process described earlier were used to develop a conceptual 

model of the relations between urban related hydrology, habitat, and nonstormflow chemistry, with fish and invertebrate 

community structure in the Fountain Creek basin, 2003–2005. 

The conceptual model is intended in part to guide future work 

relating environmental variables to biological communities in 

the Fountain Creek basin. 

Urban-Related Environmental 

Variables

After the removal of redundant variables and variable 

reduction as described previously in the Data Analysis section, 

the environmental data set of 93 variables was reduced to 8 

that were related to ISC but not related to elevation—four HIs, 

three habitat, and one nonstormflow water chemistry (table 6). 

The data reduction process restricted the analysis to those 

streamflow, habitat, and nonstormflow chemistry variables that 

were related to urbanization. Designing a study to separate the 

effects of changes in biological communities that occur naturally along a longitudinal elevation gradient from urbanization 

along the Front Range of Colorado is challenging. By also 

removing those variables that were related to elevation from 

the final list, it was assumed that the influence of known longitudinal elevation gradients inherent with this dataset could be 

partially removed from the analysis. Therefore, the results of 

the BIO-ENV analysis should be an indication of the strength 

of the influence of the remaining urban-related environmental 

variables in the dataset on biological communities.

Urban-Related Environmental Variables 13
Stream Hydrology

In this study, a pattern consistent with previously 

observed responses of stream hydrology to urbanization 

(Poff and others, 1997; Walsh and others, 2005) was evident 

(table 6). All of the HIs are considered measurements of 

stormflow hydrology, such as high flow magnitude (MH20), 

high flow frequency (FH1 and FH5), and stream flashiness 

(RA8, number of reversals). This finding suggested that the 

influence of urbanization was associated with stormflow 

hydrology in the Fountain Creek basin during the study period. 

Two of the stormflow variables (MH20 and FH1) had the 

strongest relation (rho values = 0.81 and 0.76) with urbanization, measured as ISC (table 6). 

Unlike previous studies in the arid West (McMahon and 

others, 2003; Sprague and others, 2006) that had limited success in associating the effects of urbanization with streamflow 

characterization, this study provided evidence linking urbanization with stream hydrology—specifically stormflow hydrology in the Fountain Creek basin. The differential success of 

these studies might be attributable to the hydrologic data that 

were collected, computed, and analyzed or the differences in 

study design. The McMahon and others (2003) and Sprague 

and others (2006) studies were gradient designs that sampled 

many sites along a gradient of urbanization over a short time 

period. In the gradient design, there may not have been enough 

storms that affected each site along the gradient of urbanization, coupled with the intense water management that occurs 

in arid areas, to signal a response in hydrology. Urbanization, 

climate, and intense water regulation, including transbasin 

diversions, agricultural and domestic water use, reservoir storage, and WWTF discharge were common in part to all of these 

studies.

This study differed from those of McMahon and others 

(2003) and Sprague and others (2006) by using continuous 

stream discharge rather than stage-related data to characterize stream hydrology over 3 years. Natural stream channels 

experience episodes of scour and deposition that are often 

associated with the ascending and falling limbs of a stream 

rise (Rantz and others, 1982). Because of this, the relation 

between stream discharge and stage-related data must be 

defined empirically with stream discharge measurements on a 

periodic or stream-rise basis. Thus the use of stage-related data 

as a surrogate for continuous stream discharge might not be 

appropriate or accurate in the West or on streams with unstable 

stage-discharge relations, which are fairly common along the 

Front Range of Colorado. Additionally, monitoring stream 

discharge and simultaneous changes in urbanization over multiple years may have made the relation between hydrology and 

urbanization more apparent in this study. 

Habitat

Three habitat variables also were strongly correlated with 

ISC in the study area, and other urban- related factors—stormflow and water chemistry (table 6). Percent pool, bank height, 

and lower bank capacity can be categorized as measurements 

of channel morphology. The geomorphic channel features, 

percent pool and bank height, were measured directly. Lower 

bank capacity is an RBP habitat characteristic that received 

Table 6. Correlation matrix showing Spearman’s rho values relating impervious surface cover and eight environmental 

variables used in the exploratory multivariate analysis (BIO-ENV procedure). All correlations were significant at P < 0.05.

[ISC, impervious surface cover; MH20, drainage area normalized annual maximum daily mean flow; FH1, high flood pulse count 1; FH5, flood 

frequency; RA8, number of reversals; pctPOOL, percent of reach length comprised of pool; LBCAP, lower bank channel capacity; MAXBANKHT, 

maximum bank height; DNO23, dissolved nitrite plus nitrate; <, less than]

Environmental 

variable type Variable code1 ISC MH20 FH1 FH5 RA8 pctPOOL LBCAP MAXBANKHT

Streamflow MH20 0.81

Streamflow FH1 0.76 0.56

Streamflow FH5 0.63 0.48 0.66

Streamflow RA8 0.66 0.61 0.62 0.69

Habitat pctPOOL –0.67 –0.66 –0.70 –0.55 –0.54

Habitat LBCAP –0.63 –0.67 –0.63 –0.47 –0.44 0.70

Habitat MAXBANKHT 0.69 0.59 0.66 0.39 0.34 –0.42 –0.47

Chemistry DNO23 0.70 0.66 0.55 0.46 0.55 –0.58 –0.70 0.56

1

See tables 2, 4 and 5.

14 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
a ranked score, but the ranking required the measurement of 

the width-to-depth ratio of the channel in the stream reach. 

These relations were consistent with previous studies, which 

determined that streamflow has a direct influence on channel morphology features, such as bank height, bank angle, 

channel width, and streambed substrate (Konrad and Booth, 

2005). Previous National Water-Quality Assessment Program 

(NAWQA) gradient studies have not found such strong correlations between urbanization and environmental variables 

(Short and others, 2005). 

Results from this study indicated that stormflow was 

strongly related to urbanization and habitat. The erosive 

properties of higher and more attenuated peak flows have the 

ability to alter stream geomorphology by destroying riffles 

and pools, destabilizing banks, widening channels, and filling 

interstitial spaces between gravels and cobbles (Burton and 

Pitt, 2002; Pizzuto and others, 2000). In this study direct measurements were made of stream habitat features except bank 

stability. However, bank height and angle were measured as 

surrogates for bank stability. The destruction of substrate heterogeneity by sediment deposition at sites with unstable banks 

directly eliminates habitat required by benthic communities 

(Wood and Armitage, 1997). Increased sediment transport 

during high flows also has the potential to bury or scour entire 

localized populations of invertebrates (Matthaei and others, 

1999; Waters, 1995). Reproductive success of lithophilic 

fish spawners, such as the cyprinids, central stoneroller, and 

longnose dace and the percid Arkansas darter also might be 

reduced because of the alteration of suitable spawning habitats, smothering of eggs, or decreased emergence caused by 

the entrapment of larval fish. Also, sediment deposition could 

decrease growth and recruitment of fish populations by altering the availability of food sources. 

Water Chemistry

Dissolved nitrite plus nitrate (milligrams per liter), a 

nutrient, was the only water chemistry constituent related to 

ISC and other urban-related environmental variables in this 

study (table 6). This observation was consistent with previous 

studies, but unlike those studies, other consistent responses of 

water chemistry in response to urbanization were not detected 

in the current study. Those responses include increases in 

water temperature, specific conductance, and bacteria (Walsh 

and others, 2005; Coles and others, 2004; Tate and Heiny, 

1995). However, additional water chemistry data including metals, trace elements, volatile organic compounds, and 

pesticides were not collected at all sites during this study, but 

have been demonstrated to be associated with urbanization 

as well as having biological effects on aquatic communities 

(Sprague and others, 2006; Kennen and Ayers, 2002). Sprague 

and others (2006) completed their work nearby in the South 

Platte River basin and used semipermeable membrane devices 

(SPMDs) to sample organic compounds. Their results indicated strong relation between urbanization and polycyclic 

aromatic hydrocarbons (PAHs). 

Relating Urban-Related Environmental 

Variables with Patterns in Biological 

Community Structure

Fish Communities

Results of BIO-ENV indicated that urban-related environmental variables poorly explained patterns in fish community 

structure in the Fountain Creek basin (table 7). Of the 255 possible combinations of the 8 environmental variables evaluated 

for explaining fish community structure, the best subset only 

correlated with fish community structure at rho = 0.25 (subset 

18, table 7). This two-variable subset included the variables 

nitrite plus nitrate concentration and maximum bank height. 

Several studies have shown changes in fish community 

structure associated with urbanization (Long and Schorr, 2005; 

Roy and others, 2005; Albanese and Matlack, 1999; Wang and 

others, 1997). Typically, diversity declines and the abundance 

of tolerant species increases with increasing urbanization 

(Paul and Meyer, 2001). Many of these previous studies were 

conducted in areas of high fish diversity (>30 species per 

site) with a wide variety of specialist or endemic species. In 

this study, and in an urban gradient study in the South Platte 

River basin (Sprague and others, 2006), no strong associations between urban-related hydrology or other meaningful 

measures of urbanization and fish community structure were 

found. This lack of strong association between urbanization 

and fish community structure in these two regional studies 

might be the result of current fish distribution patterns in many 

small transition zone streams of Colorado, where sites are 

dominated by a relatively small number of generalist species 

(<6 species per site).

Even under natural conditions, fish assemblages of 

streams in the Great Plains typically are comprised of more 

tolerant species than assemblages in less extreme habitats 

(Matthews, 1986). This, combined with human-induced 

streamflow modifications, habitat alterations, and changes in 

water quality that have occurred for nearly 150 years in transition zone streams (Fausch and Bestgen, 1997), likely truncated present day fish faunas to those that can tolerate a wide 

variety of extreme environmental conditions. The present-day 

tolerant fish assemblage probably minimized the urban-related 

effects on fish community structure in this and in the Sprague 

and others (2006) study. Similar results have been observed 

in Coastal Plain streams of Maryland, where early modifications to stream systems truncated local fish faunas, possibly 

masking fish-community response to contemporary urbanization (Morgan and Cushman, 2005). Others have suggested that 

fish-community structure is not a good indicator of stream 

health in nearby plains streams of Colorado for similar reasons 

(Bramblett and Fausch, 1991; Schrader, 1989). 

Relating Urban-Related Environmental Variables with Patterns in Biological Community Structure 15
Table 7. Correlation coefficients associated with the best subsets of urban-related environmental variables describing biological community struct

multivariate analysis (BIO-ENV procedure).[Each subset presented represents the highest correlation of 1 through 8 variable combinations for each assemblage type. The strongest and most parsimonious subset is boldedmultihabitat; Nitrite + Nitrate Concentration, dissolved nitrite plus nitrate concentration; Max, maximum; Pct, percent; RTH, richest targeted habitat]

Subset 

number

Number of 

variables

Spearman’s rho Variables included in model

Invertebrate QMH

1 1 0.56 Lower Bank Capacity2 2 0.67 Nitrite + Nitrate Concentration, Lower Bank Capacity3 3 0.71 Nitrite + Nitrate Concentration, Flood Pulse Count, Lower Bank Capacity4 4 0.71 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Lower Bank Capacity5 5 0.70 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Mean Annual Normalized Max Flow, Lower Bank Capacity6 6 0.71 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Number of Reversals, Mean Annual Normalized Max Flow, Lower 7 7 0.70 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Number of Reversals, Mean Annual Normalized Max Flow, Pct Po8 8 0.67 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Number of Reversals, Mean Annual Normalized Max Flow, Pct Po

Bank Height

Invertebrate RTH 

9 1 0.28 Mean Annual Normalized Max Flow

10 2 0.33 Mean Annual Normalized Max Flow, Lower Bank Capacity11 3 0.35 Flood Pulse Count, Mean Annual Normalized Max Flow, Lower Bank Capacity12 4 0.34 Nitrite + Nitrate Concentration, Flood Pulse Count, Mean Annual Normalized Max Flow, Lower Bank Capacity13 5 0.33 Nitrite + Nitrate Concentration, Flood Pulse Count, Number of Reversals, Mean Annual Normalized Max Flow, Lower Bank Capacity14 6 0.32 Nitrite + Nitrate Concentration, Flood Pulse Count, Number of Reversals, Mean Annual Normalized Max Flow, Lower Bank Capacity, M15 7 0.30 Nitrite + Nitrate Concentration, Flood Pulse Count, Number of Reversals, Mean Annual Normalized Max Flow, Pct Pool, Lower Bank C16 8 0.29 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Number of Reversals, Mean Annual Normalized Max Flow, Pct Po

Bank Height

Fish

17 1 0.16 Max Bank Height18 2 0.25 Nitrite + Nitrate Concentration, Max Bank Height19 3 0.24 Nitrite + Nitrate Concentration, Lower Bank Capacity, Max Bank Height20 4 0.23 Nitrite + Nitrate Concentration, Flood Pulse Count, Lower Bank Capacity, Max Bank Height21 5 0.20 Nitrite + Nitrate Concentration, Flood Pulse Count, Mean Annual Normalized Max Flow, Lower Bank Capacity, Max Bank Height22 6 0.17 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Mean Annual Normalized Max Flow, Lower Bank Capacity, Max B23 7 0.13 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Number of Reversals, Mean Annual Normalized Max Flow, Lower 

Height

24 8 0.09 Nitrite + Nitrate Concentration, Flood Pulse Count, Flood Frequency, Number of Reversals, Mean Annual Normalized Max Flow, Pct Po

Bank Height
Invertebrate Communities

Previous urban-impact studies have found strong invertebrate community response to urbanization (Coles and others, 

2004; Roy and others, 2003; Kennen, 1999; Jones and Clark 

1987). Typically, pollution tolerant taxa replace pollution 

sensitive taxa resulting in changes in diversity and invertebrate 

abundance as urbanization increases (Paul and Meyer, 2001). 

Several local studies have found mixed results regarding the 

direct influence of urbanization on invertebrate community 

structure. In nearby urban-related studies in the South Platte 

River basin, Sprague and others (2006) did not find any strong 

relations between urbanization and invertebrate community 

structure; whereas others were able to show at least partial 

effects (Voelz and others, 2005; Tate and Heiny, 1995). 

In this study, several combinations of urban related variables were strongly related to invertebrate community structure (table 7). The strongest and most parsimonious relation 

of any BIO-ENV subset (rho = 0.71) was between QMH data 

and three environmental variables that represented hydrology 

(FH1-flood pulse count), habitat (lower bank capacity), and 

water chemistry (nitrite plus nitrate concentration), (subset 

3, table 7). In addition, there were several other competing 

subsets that described similar correspondence between other 

combinations of environmental variables and patterns in QMH 

community structure (table 7). The three variables in subset 

3, table 7 (FH1-flood pulse count, lower bank capacity, and 

nitrite plus nitrate concentration) were consistently found in all 

competing QMH subsets indicating that these three variables 

are likely contributing most to matching patterns in environmental and QMH ordinations. Interestingly, the addition of 

other environmental variables (FH5-flood frequency, MH20-

drainage area normalized annual maximum daily mean flow 

and percent pool) into subsequent subsets did not deteriorate 

the relation between QMH community structure and urbanrelated environmental variables (subsets 4-7, table 7). This 

may indicate that even with a relatively intense variable reduction process described above, there was still some redundancy 

among environmental variables as they are related to QMH 

community structure. 

The BIO-ENV subset with the strongest correlation 

to RTH community structure consisted of two hydrologic 

variables (FH1-flood pulse count, MH20- drainage area normalized annual maximum daily mean flow) and one habitat 

variable (lower bank capacity) (subset 11, table 7). Although 

this was the strongest BIO-ENV subset for the RTH data, the 

relation between patterns in RTH community structure and 

environmental variables was relatively weak (rho = 0.35). As 

with the QMH data, there were other competing subsets that 

described RTH community structure almost as well as subset 

11 (subsets 10, 12, 13, table 7), again suggesting at least some 

redundancy across environmental variables. Interestingly, 

flood pulse count and lower bank capacity were included in 

RTH and QMH best subsets (table 7), which might be a result 

of the overlap in taxa between the two sample types (RTH 

with 145 taxa, QMH with 205 taxa) and how they related to 

the environmental variables in the subset. 

Varying results between this and previous studies are 

likely caused by differences in study design. Studies that collected samples from several sites across a short elevation gradient over multiple years (current study and Voelz and others, 

2005) showed interpretable relations between urbanization and 

invertebrate community structure. By contrast, studies collecting samples from several sites along a gradient of urbanization across a short time period showed little relation between 

urbanization and invertebrate community structure (Sprague 

and others, 2006) with one exception (Tate and Heiny, 1995). 

Tate and Heiny (1995) collected samples along an extreme 

elevation gradient over a short time period and found relations 

between urban land use and invertebrate community structure. 

As intended, the Tate and Heiny (1995) study design enhanced 

the natural differences (for example, elevation) among sites 

that contributed to the many relations found in that study. 

Because urbanization and elevation were highly correlated, 

invertebrate community structure changed with both elevation 

and urbanization. Although sites in this study were spatially 

auto-correlated along a relatively short elevation gradient 

(table 1), an effort was made to remove the natural influence 

of elevation in the analysis by removing environmental variables that were strongly correlated with elevation. Therefore, 

these results should represent a clearer picture of the influence 

of urbanization on invertebrate community structure in the 

Fountain Creek basin within the bounds of the dataset. 

Although little is known about regional historic invertebrate community structure, it is likely that present-day 

invertebrate communities in Front Range transition zone 

streams have been truncated to a group of tolerant species by 

past anthropogenic activities (Zuellig and others, 2007; Zuellig 

and others, 2006; Kondratieff and Baumann, 2002; Cordeiro, 

1999; McCafferty and others, 1993). As with fish, invertebrate 

communities on the plains are naturally more tolerant than 

those from less extreme habitats. Surprisingly, even with present-day tolerant taxa dominating all sites in the study by Voelz 

and others (2005) and the current study, invertebrate communities in Front Range streams apparently were influenced by 

urbanization through hydrology, habitat, and water chemistry 

within short urban gradients (tables 1 and 7). These linked 

relations (for example, urban to hydrology, habitat, and water 

chemistry to invertebrates) were not apparent in a shorter term 

study in the South Platte River basin (Sprague and others, 

2006). Short-term monitoring of many streams in an ecoregion 

can sometimes be an effective way to evaluate water quality 

(Kay and others, 2001; Clements and others, 2000). However, 

long-term studies provide the necessary background information crucial for separating the differences between natural and 

anthropogenic changes in water quality (Naiman and others, 

1995; Elliott, 1990). Multiple-year studies as opposed to single 

sampling events across a large number of sites may be needed 

to better understand the influence of urbanization on stream 

communities along the Front Range of Colorado. 

Relating Urban-Related Environmental Variables with Patterns in Biological Community Structure 17
Major Findings

This study demonstrated links between urbanization 

(impervious surface coverage), stormwater hydrology (maximum daily flow, number of floods, and number of reversals), 

habitat (percent pool, lower bank capacity, and maximum 

bank height), water chemistry (dissolved nitrite plus nitrate), 

and patterns in aquatic community structure in the Fountain 

Creek basin, 2003 to 2005. Important relations from statistical 

analyses are summarized in figure 2. Qualitative invertebrate 

samples collected from all habitat types present at each site 

(qualitative multihabitat) demonstrated the strongest relation 

between urban-related environmental variables and patterns 

in aquatic community structure. Variables related to elevation were removed in order to obtain a better understanding 

of urban influence on aquatic communities. The strongest 

and most parsimonious subset of environmental variables 

describing patterns in QMH invertebrate community structure 

included high flood pulse count, lower bank capacity, and 

nitrite plus nitrate (fig. 2, table 7). Several other subsets of 

environmental variables resulted in competing combinations 

but always included the three variables found in the most parsimonious subset (table 7).

 Semiquantitative invertebrate samples collected from 

a single habitat type at each site (richest targeted habitat) 

demonstrated weaker links between patterns in community 

structure and environmental variables. Patterns in fish community structure were not well explained by the selected 

urban-related environmental variables addressed in this study. 

There are likely other environmental variables unrelated to 

urbanization not evaluated in this report that will better explain 

RTH invertebrate and fish community structure in the Fountain 

Creek basin.

Studying the relations between biota and the environment 

is complex in transition zone streams along the Front Range 

of Colorado. These ecosystems are influenced by natural 

gradients as well as by multiple interacting stressors, including 

urban development, agriculture, and intensive water management. Maintenance or protection of these stream ecosystems 

Urb

a

niz

atio

n

M

e

a

s

ure

d

a

s

Im

p

ervio

u

s

S

urfa

c

e

MH20-Normalized maximum daily mean flow

FHI-High flood pulse count

FH5-Flood frequency

RA8-Number of reversals

DNO23-dissolved

nitrite + nitrate

pctPOOL-Percent pool

LBCAP-Lower bank

capacity

MAXBANKHT-Maximum

bank height

Invertebrate RTH

rho = 0.35

Invertebrate QMH

rho = 0.71

Fish

rho = 0.25

H

y

d

r

olo

g

y

H

a

bitat

W

ate

r

C

h

e

mistry

Figure 2. Conceptual model showing the primary urban-related environmental variables associated with stream ecology in 

the Fountain Creek basin, Colorado. Arrows in the model connecting urbanization to environmental variables represent strong 

associations between urbanization, hydrology, habitat, and water chemistry found in the correlation analyses (table 6). Arrows 

connecting environmental variables to invertebrate and fish communities represent the links between environmental variables and 

patterns in community structure identified with the exploratory multivariate analysis (BIO-ENV procedure) (table 7). Rho values

indicate the strength of the match between ordinations of highlighted environmental variables and biological communities. QMH 

represents qualitative multihabitat samples and RTH represents richest targeted habitat samples.

18 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
will involve understanding how aquatic communities are 

structured by natural factors as well as by interacting stressors. 

Identifying other factors, in addition to urban-related environmental variables found in this study, ultimately will allow better management of stream ecosystems in the face of continued 

urban development along the Front Range of Colorado.

Summary

Changes in stream hydrology, geomorphology, water 

chemistry, water temperature, aquatic communities, and 

biological processes have been attributed to urbanization. As 

urbanization occurs the percentage of impervious surfaces 

in a watershed increases, which decreases the infiltration of 

precipitation into soils and ultimately leads to increased runoff 

into streams. Aquatic communities are strongly influenced by 

the hydrologic regime, physical habitat, and water quality of 

flowing water, and when these components of stream ecosystems are disturbed, it can adversely affect migration, growth, 

recruitment, reproduction, competition, and disease progression within aquatic communities. 

The influence of urbanization on stream discharge 

(streamflow), habitat, and aquatic communities is emerging as 

an issue of importance. Few studies focusing on the influence 

of urbanization on stream ecology have been conducted in 

the arid western United States. To address these concerns the 

USGS, in cooperation with Colorado Springs City Engineering, began a study of the Fountain Creek basin in 2003 to 

evaluate the influence of urbanization on stream hydrology, 

habitat, water chemistry, and aquatic communities. This report 

summarizes previous biological studies from Fountain Creek; 

evaluates the relations among stream hydrology, environmental characteristics, and biological attributes associated with 

urbanization in the Fountain Creek basin from 2003 to 2005; 

and develops a conceptual model of the relations between 

urban-related environmental variables and biological communities for the Fountain Creek basin.

There are likely 20 fish species native to the Arkansas 

River basin in Colorado. However, current habitat conditions 

associated in the Fountain Creek basin likely do not satisfy 

the species-specific life history requirements for all 20 native 

fishes. Based on limited historical accounts and basic knowledge on the habitat requirements for the native fishes found 

in the Arkansas River basin, a conservative estimate of 

16 species are likely native to the portion of Fountain Creek 

basin evaluated in this study. Additionally, there are three state 

listed species in the Fountain Creek basin: southern redbelly 

dace (Phoxinus erythrogaster, state endangered), Arkansas 

darter (Etheostoma cragini, state threatened), and flathead 

chub (Platygobio gracilis, state species of concern). Very little 

published information about fish and aquatic invertebrates, 

or habitat conditions of Fountain Creek, can be found prior 

to 1982. As a result, little is known about the ecology and 

distributions of fish and aquatic invertebrates that historically 

occupied Fountain Creek. 

Stream attributes characterized in this study included 

hydrology, habitat, selected water chemistry, and fish and 

invertebrate community structure. At each site physical habitat 

was characterized at the basin-and-reach spatial scales. Land 

uses in the Fountain Creek basin were used to estimate impervious surface cover. Response of stream hydrology to urbanization was evident among hydrologic variables that described 

stormwater flow. These indices included one measurement 

of high-flow magnitude, two measurements of high-flow 

frequency, and one measurement of stream flashiness. This 

indicated that the influence of urbanization was associated 

with stormflow hydrology in the Fountain Creek basin.

A multivariate technique was used to create subsets of 

environmental variables that best described patterns in fish 

and invertebrate community structure. Invertebrate community structure was characterized by semi-quantitative 

richest targeted habitat (RTH) and qualitative multihabitat 

samples (QMH). The strongest and most parsimonious subset 

describing patterns in QMH invertebrate community structure 

included high flood pulse count, lower bank capacity, and 

nutrients. Several other subsets of environmental variables 

resulted in competing combinations but always included the 

three variables found in the most parsimonious subset. This 

finding indicated that complex relations existed between environmental characteristics and biota, which required multiple 

types of data (hydrology, habitat, water chemistry) to explain 

observed patterns in QMH invertebrate community structure. Fish and RTH invertebrate community structure showed 

weaker links between urban-related environmental variables 

and biological patterns. 

This study found that patterns in fish and invertebrate 

community structure from the Fountain Creek basin were 

associated with a variety of environmental characteristics 

influenced by urbanization. These findings were consistent 

with some of the effects of urbanization on stream ecology 

that have been commonly observed by other researchers. A 

conceptual model was developed that showed the influence of 

urbanization on environmental variables and their relation to 

fish and invertebrate assemblages that should help guide future 

studies. Patterns in invertebrate QMH data were explained by 

a combination of stream discharge (streamflow), habitat, and 

water-chemistry variables. 

Studying the relations between biota and the environment 

is complex in transition zone streams along the Front Range 

of Colorado. These ecosystems are influenced by natural 

gradients as well as by multiple interacting stressors, including 

urban development, agriculture, and intensive water management. Maintenance or protection of these stream ecosystems 

will involve understanding how aquatic communities are 

structured by natural factors as well as by interacting stressors. 

Identifying other factors, in addition to urban-related environmental variables found in this study, ultimately will allow better management of stream ecosystems in the face of continued 

urban development along the Front Range of Colorado.

Summary 19
References Cited

Albanese, B., and Matlack, G., 1999, Utilization of parking 

lots in Hattiesburg, Mississippi, USA, and impacts on local 

streams: Environmental Management, v. 24, p. 265–271.

Arnold, C.L., and Gibbons, J.C., 1996, Impervious surface 

coverage—The emergence of a key environmental indicator: Journal of American Planning Association, v. 62, 

p. 243−258.

Barbour, M.T., Gerritsen, J., Snyder, B.D., and Stribling, J.B., 

1997, Revision to rapid bioassessment protocols for use in 

streams and rivers—Periphyton, benthic macroinvertebrates 

and fish: U.S. Environmental Protection Agency, Office of 

Water, Washington, D.C., EPA 841–D–97–002, variously 

paged.

Bramblett, R.G., and Fausch, K.D., 1991, Variable fish communities and the index of biotic integrity in a western Great 

Plains River: Transactions of the American Fisheries Society, v. 120, p. 752–769.

Bruce, J.F., 2002, Characterization and analysis of temporal 

and spatial variations in habitat and macroinvertebrate community structure, Fountain Creek Basin, Colorado Springs 

and vicinity, Colorado, 1998–2001: U.S. Geological Survey 

Water-Resources Investigations Report 02–4093, 28 p.

Burton, G.A., Jr., and Pitt, R.E., 2002, Stormwater effects 

handbook—A toolbox for watershed managers, scientists, 

and engineers: Boca Raton, Fla., Lewis Publishers, 911 p.

Clarke, K.R., and Ainsworth, M., 1993, A method of linking 

multivariate community structure to environmental variables: Marine Ecology Progress Series, v. 92, p. 205−219.

Clarke, K.R., and Warwick, R.M., 2001, Change in marine 

communities: An approach to statistical analysis and interpretation, 2d ed.: Plymouth Marine Laboratory, Plymouth, 

UK, 172 p.

Clements, W.H., Carlisle, D.M., Lazorchak, J.M., and Johnson, P.C., 2000, Heavy metals structure benthic communities in Colorado mountain streams: Ecological Applications 

v. 10, p. 626–638.

Coles, J.F., Cuffney, T.F., McMahon, Gerard, and Beaulieu, 

K.M., 2004, The effects of urbanization on the biological, physical, and chemical characteristics of coastal New 

England streams: U.S. Geological Survey Professional 

Paper 1695, 47 p.

Cordeiro, J.R., 1999, Distribution and habitat of freshwater 

mussels (Bivalvia: Unionoida: Unionidae) in Colorado: 

Natural history inventory no. 19, University of Colorado 

Museum, Boulder, Colorado, 56 p.

Cross, F.B., and Moss, R.E., 1987, Historic changes in fish 

communities and aquatic habitats in plains streams of Kansas, in Matthews, W.J., and Heins, D.C., eds., Community 

and evolutionary ecology of North American stream fishes: 

University of Oklahoma Press, Norman Okla., p. 155−165.

Crowfoot, R.M., Boulger, R.W., Payne, W.F., and O’Neill, 

G.B., 2003, Water resources data, Colorado, water year 

2003, v. 1: U.S. Geological Survey Water-Data Report 

CO 03–01, 577 p.

Crowfoot, R.M., Payne, W.F., O’Neill, G.B., and Boulger, 

R.W., 2004, Water resources data, Colorado, water year 

2004, v. 1: U.S. Geological Survey Water-Data Report 

CO 04–01, 344 p.

Crowfoot, R.M., Payne, W.F., O’Neill, G.B., Boulger, R.W., 

and Sullivan, J.R., 2005, Water resources data, Colorado, 

water year 2005.

Cuffney, T.F., 2003, User’s manual for the National WaterQuality Assessment Program invertebrate data analysis system (IDAS) software—Version 3: U.S. Geological Survey 

Open-File Report 03–172, 103 p.

Dunne, T., and Leopold, L.B., 1978, Water in Environmental 

Planning: New York, W.H. Freeman and Company, 817 p.

Edelmann, P., Ferguson, S.A., Stogner, R.W., Sr., August, M., 

Payne, W.F., and Bruce, J.F., 2002, Evaluation of water 

quality, suspended sediment, and stream morphology with 

an emphasis on effects of storm flow on Fountain and 

Monument Creek basins, Colorado Springs and vicinity, 

Colorado, 1981 through 2001: U.S. Geological Survey 

Water-Resources Investigations Report 02–4104, 59 p.

Edmunds, G.F., and McCafferty, W.P., 1984, Ephemera compar—An obscure Colorado burrowing mayfly 

(Ephemeroptera: Ephemeridae): Entomological News, v. 95, 

p.186–188.

Edwards, T.K., and Glysson, G.D., 1988, Field methods for 

measurement of fluvial sediment: U.S. Geological Survey 

Open-File Report 86–531, 117 p.

Elliott, J.M., 1990, The need for long-term investigations in 

ecology and the contribution of the Freshwater Biological 

Association: Freshwater Biology, v. 23, p. 1–5.

Everitt, B.S., 2002, The Cambridge Dictionary of Statistics, 2d 

ed.: New York, Cambridge University Press, p. 410.

Fausch, K.D., and Bestgen, K.R., 1997, Ecology of fishes 

indigenous to the central and southwestern Great Plains, in

Knopf, F.L., and Samson, F.B., eds., Ecology and conservation of Great Plains vertebrates: New York, Springer-Verlag, 

Inc., p. 131−166.

20 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
Fishman, M.J., 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of inorganic and organic constituents in water 

and fluvial sediments: U.S. Geological Survey Open-File 

Report 93–125, 217 p.

Fitzgerald, D.G., Lanno, R.P., and Dixon, D.G., 1999, A 

comparison of a sentinel species evaluation using creek 

chub (Semotilus atromaculatus Mithcill) to a fish community evaluation for the initial identification of environmental 

stressors in small streams: Ecotoxicology, v. 8, p. 33−48.

Guy, H.P., 1969, Laboratory theory and methods for sediment 

analysis: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. C1, 58 p.

Hansen, W.R., and Crosby, E.J., 1982, Environmental geology 

of the Front Range urban corridor and vicinity, Colorado 

with a specific section on Physical properties and performance characteristics of surficial deposits and rock units in 

the greater Denver area by R.R. Shroba: U.S. Geological 

Survey Professional Paper 1230, 99 p.

Henriksen, J.A., Heasley, J., Kennen, J.G., and Nieswand, 

S., 2006, Users’ manual for the hydroecological integrity 

assessment process software (including the New Jersey 

assessment tools), Fort Collins, Colo.: U.S. Geological 

Survey, Fort Collins Science Center, Open-File Report 

2006–1093, 71 p.

Hirsch, R.M., Walker, J.F., Day, J.C., and Kallio, R., 1990, The 

influence of man on hydrologic systems, in Wolaman, M.G., 

and Riggs, H.C., eds., Surface water hydrology: Boulder, 

Colo., Geological Society of America, p. 329−359.

House, M.A., Ellis, J.B., Herricks, E.E., Hvitved-Jacobsen, T., 

Seager, J., Lijklema, L., Aaldernik, H., and Clifforde, I.T., 

1993, Urban drainage—Impacts on receiving water quality: 

Water Science and Technology, v. 27, p. 117−158.

Jones, R.C., and Clark, C.C., 1987, Impact of watershed 

urbanization on stream insect communities: Water 

Resources Bulletin, v. 23, p. 1047−1055.

Kay, W.R., Halse, S.A., Scanlon, M.D., and Smith, M.J., 2001, 

Distribution and environmental tolerances of aquatic macroinvertebrate families in the agricultural zone of southwestern Australia: Journal of the North American Benthological 

Society, v. 20, p. 182−199.

Kennen, J.G., 1999, Relation of invertebrate community 

impairment to catchment characteristics in New Jersey 

streams: Journal of the American Water Resources Association, v. 35, p. 939−954.

Kennen, J.G., and Ayers, M.A., 2002, Relation of environmental characteristics to the composition of aquatic assemblages along a gradient of urban land use in New Jersey, 

1996–1998: U.S. Geological Survey Water-Resources 

Investigations Report 02–4069, 77 p.

Klein, R.D., 1979, Urbanization and stream quality impairment: Water Resources Bulletin, v. 15, p. 948−963.

Knighton, D., 1998, Fluvial forms and processes—A new 

perspective: New York, John Wiley and Sons, 383 p.

Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., 

Zaugg, S.D., Barber, L.B., and Buxton, H.T., 2002, Pharmaceuticals, hormones, and other organic wastewater contaminants in United States streams, 1999–2000—A national 

reconnaissance: Environmental Science and Technology, 

v. 36, no. 6, p. 1202−1211.

Kondratieff, B.C., and Baumann, R.W., 2002, A review of the 

stoneflies of Colorado with description of a new species of 

Capnia (Plecoptera: Capniidae): Transactions of the American Entomological Society, v. 128, p. 385–401.

Konrad, C.P., and Booth, D.B., 2005, Hydrologic changes in 

urban streams and their ecological significance: American 

Fisheries Society Symposium, v. 47, p. 157−177.

Larsen, L.S., 1981, Soil survey of El Paso County area, Colorado: Washington, D.C.: U.S. Department of Agriculture, 

Soil Conservation Service, 212 p.

LeBlanc, R.T., Brown, R.D., and FitzGibbon, J.E., 1997, 

Modeling the effects of land use change on water temperature in unregulated urban streams: Journal of Environmental 

Management, v. 49, p. 445−469.

Leopold, L.B., 1968, Hydrology for urban land planning—A 

guidebook on the hydrologic effects of urban land uses: 

Washington, D.C., U.S. Geological Survey Circular 554, 

10 p.

Loeffler, C., Miller, R., and Krieger, D.A., 1982, Arkansas 

River threatened fishes survey, Performance Report, Federal 

Aid Project SE-8-1-2: Colorado Division of Wildlife, 8 p. + 

4 Appendixes.

Long, J., and Schorr, M.S., 2005, Effects of watershed urban 

land use on environmental conditions and fish assemblages 

in Chattanooga area streams (Tennessee-Georgia): Journal 

of Freshwater Ecology, v. 20, p. 527–537.

Mathsoft, Inc., 2000, S-Plus 2000 Professional—Release 3: 

Mathsoft Inc. [CD-ROM].

Matthaei, C.D., Peacock, K.A., and Townsend, C.R., 1999, 

Scour and fill patterns in a New Zealand stream and 

potential implications for invertebrate refugia: v. 42, no. 1, 

p. 41−57.

Matthews, W.J., 1986, Physicochemical tolerance and selectivity of stream fishes as related to their geographic ranges and 

local distributions, in Matthews, W.J., and Heins, D.C., eds., 

Community and evolutionary ecology of North American 

stream fishes: Norman, Okla., University of Oklahoma 

Press, p. 111–120.

References Cited 21
Mau, D.P., Stogner, R.W., Sr., Edelman, P., 2007, Evaluation 

of storm flows and waste-water treatment plant effluent discharges on water quality, suspended sediment, and channel 

morphology for Monument and Fountain Creek watersheds, 

Colorado, 1981–2006: U.S. Geological Survey Scientific 

Investigations Report 07−5104, 76 p.

McCafferty, W.P., Durfee, R.S., and Kondratieff, B.C., 1993, 

Colorado mayflies (Ephemeroptera)—An annotated inventory: The Southwestern Naturalist, v. 38, p. 252–274.

McMahon, G., Bales, J.D., Coles, J.F., Giddings, E.M.P., and 

Zappia, H., 2003, Use of stage data to characterize hydrologic conditions in an urbanizing environment: Journal 

of the American Water Resources Association, v. 39, 

p. 1529−1546.

McMurry, L.M., Oethinger, M., and Levy, S.B., 1998, Overexpression of marA, soxS, or acrAB produces resistance to 

triclosan in laboratory and clinical strains of Escherichia

coli: FEMS Microbiology Letters, v. 166, no. 2, p. 305−309. 

Meador, M.R., Hupp, C.R., Cuffney, T.F., and Gurtz, M.E., 

1993, Methods for characterizing stream habitat as part of 

the National Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 93–408, 48 p.

Morgan, R.P., and Cushman, S.F., 2005, Urbanization effects 

on stream fish assemblages in Maryland, USA: Journal 

of the North American Benthological Society, v. 24, 

p. 643–655.

Moulton, S.R., II, Carter, J.L., Grotheer, S.A., Cuffney, T.F., 

and Short, T.M., 2000, Methods of analysis by the U.S. 

Geological Survey National Water-Quality Laboratory—

Processing, taxonomy, and quality control of invertebrate 

samples: U.S. Geological Survey Open-File Report 02–212, 

49 p.

Nadler, C.T., and Schumm, S.A., 1981, Metamorphosis of 

South Platte and Arkansas Rivers, eastern Colorado: Physical Geography, v. 2, p. 95−115.

Naiman, R.J., Magnuson, J.J., McKnight, D.M., and Stanford, 

J.A., 1995, The freshwater imperative, a research agenda:

Island Press, Washington, D.C.

Nesler, T.P., Bennett, C., Melby, J., Dowler, G., and Jones, M., 

1999, Inventory and status of Arkansas River native fishes 

in Colorado: Colorado Division of Wildlife, Final Report, 

120 p.

Olden, J.D., and Poff, N.L., 2003, Redundancy and choice of 

hydrologic indices for characterizing streamflow regimes: 

River Research and Applications, v. 19, p. 101−121.

Omernik, J.M., 1987, Ecoregions of the conterminous United 

States: Annals of the Association of American Geographers, 

v. 77, p. 118−125.

Orth, D.J., 1983, Aquatic habitat measurements, in Nielsen, 

L.A., and Johnson, D.L., eds., Fisheries techniques, Chapter 

4: Bethesda, Md., American Fisheries Society, p. 61–84.

Paul, M.J., and Meyer, J.L., 2001, Streams in the urban landscape: Annual Review of Ecology and Systematics, v. 32, 

p. 333−365.

Pikes Peak Area Council of Governments, 2005, Fountain 

Creek watershed, impervious surface area and watershed 

health analysis, accessed October 3, 2006, at http://www.

fountain-crk.org/Reports/impervious%20surface%20report.

htm

Pitt, R.E., Field, R., Lalor, M., and Brown, M., 1995, Urban 

stormwater toxic pollutants—Assessment, sources, 

and treatability: Water Environment Research, v. 67, 

p. 260−275.

Pizzuto, J.E., Hession, W.C., McBride, M., 2000, Comparing 

gravel-bed rivers in paired urban and rural catchments of 

southeastern Pennsylvania: Geology, v. 28, p. 79−82.

Poff, N.L., Allan, J.D., Bain, M.B., Karr, J.R., Prestegaard, 

K.L., Richter, B.D., Sparks, R.E., and Stromberg, J.C., 

1997, The natural flow regime—A paradigm for river conservation and restoration: Bioscience, v. 47, p. 769−784.

Pusey, B.J., Kennard, M.J., Arthur, J.M., and Arthington, 

A.H., 1998, Quantitative sampling of stream fish assemblages: Single- vs. multiple-pass electrofishing: Australian 

Journal of Ecology, v. 23, p. 365−374.

Rahel, F.J., Hubert, W.A., 1991, Fish assemblages and habitat 

gradients in a Rocky Mountain Great-Plains stream—Biotic 

zonation and additive patterns of community change: 

Transactions of the American Fisheries Society, v. 120, 

p. 319−332.

Rantz, S.E., and others, 1982, Measurement and computation 

of streamflow—Volume 2. Computation of discharge: U.S. 

Geological Survey Water-Supply Paper 2175, 347 p.

Riordan, E.J., Griggs, N.S., Hiller, R.L., 1978, Measuring the 

effects of urbanization on the hydrologic regime, in Conference on International Symposium on Urban Drainage, 1st, 

Southampton, UK., 1978, Proceedings: American Society 

of Civil Engineers, p. 496−511.

Roy, A.H., Rosemond, A.D., Paul, M.J., Leigh, D.S., and 

Wallace, J.B., 2003, Stream macroinvertebrate response to 

catchment urbanization (Georgia, U.S.A.): Freshwater Biology, v. 48, p. 329−346.

Roy, A.H., Freeman, M.C., Freeman, B.J., Wenger, S.J., 

Ensign, W.E., and Meyer, J.L., 2005, Investigating hydrologic alteration as a mechanism of fish assemblage shifts in 

urbanizing streams: Journal of the North American Benthological Society, v. 24, p. 656−678.

22 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
Schrader, L.H., 1989, Use of the index of biotic integrity to 

evaluate fish communities in Western Great Plains streams: 

Masters Thesis, Colorado State University, Fort Collins, 

Colorado, 120 p.

Schreurs, R.M., Legler, J., Artola-Garicano, E., Sinnige, T.L., 

Lanser, P.H., Seinen, W., and Van Der Burg, B., 2004, In 

vitro and in vivo antiestrogenic effects of polycyclic musks 

in zebrafish: Environmental Science and Technology, v. 38, 

no. 4, p. 997−1002.

Short, T.M., Giddings, E.M., Zappia, H., and Coles, J.F., 2005, 

Urbanization effects on stream habitat characteristics in 

Boston, Massachusetts; Birmingham, Alabama; and Salt 

Lake City, Utah, in Brown, L.R., Gray, R.H., Hudges, R.M., 

and Meador, M.R., eds., Effects of urbanization on stream 

ecosystems: American Fisheries Society, Symposium 47, 

Bethesda, Maryland, p. 317−332.

Sprague, L.A., Zuellig, R.E., Dupree, J.A., 2006, Effects of 

urbanization on stream ecosystems in the South Platte River 

Basin, Colorado and Wyoming: U.S. Geological Survey 

Scientific Investigations Report 2006–5101–A, 141 p.

Stogner, R.W., Sr., 2000, Trends in precipitation and streamflow and changes in stream morphology in the Fountain 

Creek watershed, Colorado, 1939–99: U.S. Geological Survey Water-Resources Investigations Report 00–4130, 43 p.

Tate, C.M., and Heiny, J.S., 1995, The ordination of benthic 

invertebrate communities in the South Platte River Basin in 

relation to environmental factors: Freshwater Biology, v. 33, 

p. 439–454.

Thorpe, K.L., Hutchinson, T.H., Hetheridge, M.J., Scholze, 

M., Sumpter, J.P., and Tyler, C.R., 2001, Assessing the 

biological potency of binary mixtures of environmental 

estrogens using vitellogenin induction in juvenile rainbow 

trout (Oncorhynchus mykiss): Environmental Science and 

Technology, v. 35, no. 12, p. 2476−2481.

U.S. Environmental Protection Agency, 2000, The quality of 

our nation’s waters: EPA Report 841-S-00-001.

U.S. Geological Survey, variously dated, National field manual 

for the collection of water-quality data: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 

9, chaps. A1-A9, available online at http://pubs.water.usgs.

gov/twri9A

U.S. Geological Survey, 1974, Northeast Pueblo, Colo. quadrangle and Pinon, Colo. quadrangle: 1:24,000-scale.

Voelz, N.J., Zuellig, R.E., Shieh, Sen-Her, and Ward, J.V., 

2005, The effects of urban areas on benthic invertebrates in 

two Colorado plains rivers: Environmental Monitoring and 

Assessment, v. 101, p. 175–202.

von Guerard, Paul, 1989, Sediment-transport characteristics 

and effects of sediment transport on benthic invertebrates in 

the Fountain Creek drainage basin upstream from Widefield, southeastern Colorado 1985–88: U.S. Geological 

Survey Water-Resources Investigations Report 88–4161, 

133 p.

Walsh, C.J., Roy, A.H., Feminella, J.W., Cottingham, P.D., 

Groffman, P.M., Morgan, R.P., 2005, The urban stream 

syndrome: Current knowledge and the search for a cure: 

Journal of the North American Benthological Society, v. 24, 

p. 706−723.

Wang, L.Z., Lyons, J., and Kanehl, P., 1997, Impacts of urbanization on stream habitat and fish across multiple spatial 

scales: Environmental Management, v. 28, p. 255–266.

Ward, J.V., 1986, Altitudinal zonation in a Rocky Mountain 

stream: Archiv f. Hydrobiologie, Supplement 74, v. 2, 

p. 133−199.

Waters, T.F., 1995, Sediment in streams—Sources, biological 

effects and control: American Fisheries Society Monograph 7, 249 p.

Wolman, M.G., 1954, A method for sampling coarse riverbed 

material: Transactions of the American Geophysical Union, 

v. 35, p. 951−956.

Wood, P.J., and Armitage, P.D., 1997, Biological effects of 

fine sediment in the lotic environment: Environmental Management, v. 21, no. 2, p. 203−217.

Zuellig, R.E., Sprague, L.A., Collins, J.A., Cox, O.N., 2007, 

Aquatic communities and selected water chemistry in 

St. Vrain Creek near the City of Longmont, Colorado, 

wastewater-treatment plant, 2005 and 2006: U.S. Geological 

Survey Data Series 253, 30 p.

Zuellig, R.E., Kondratieff, B.C., and Hood, R.W., 2006, 

Studies on stoneflies (Plecoptera) of Colorado with eastern 

faunal affinities, including a new state record of the midwestern salmonfly, Pteronarcys pictetii Hagen (Plecoptera: 

Pteronarcyidae): Proceedings of the Entomological Society 

of Washington, v. 108, p. 335−340.

References Cited 23
anthropogenic Occurring because of, or influenced by, 

human activity.

base flow Sustained flow in a stream; ground-water discharge is the source of base flow in most streams.

Bray-Curtis Similarity A measure of similarity (city-block 

distance) between two samples based on the number and frequency of taxa (variables).

channelization Modification of a stream, typically by 

straightening the channel, to provide more uniform flow.

confluence The location where a tributary joins the main 

stream.

drainage basin The portion of the surface of a geographic 

area that contributes water to a stream through overland runoff.

ecological studies Studies of biological communities and 

habitat characteristics to evaluate the influence or effects of 

physical and chemical characteristics of water and hydrologic 

conditions on aquatic biota.

ecoregion An area of similar climate, landform, soil, 

potential natural vegetation, hydrology, or other ecologically 

relevant variable.

Euclidean distance A measure of the linear distance 

between two samples in multidimensional space. 

geomorphic channel units Fluvial geomorphic descriptors of 

channel shape and stream velocity. Pool, riffles, and runs are 

three types of geomorphic channel units.

habitat In general, aquatic habitat includes all nonliving 

(physical) attributes of the aquatic ecosystem (Orth, 1983), 

although living components like aquatic macrophytes and 

riparian vegetation are also included.

ichthyofauna Pertains to fish, and fishes found in a region.

loess A method of regression analysis (Locally Weighted 

Regression) in which polynomials are used to approximate the 

regression function. Often used for smoothing scatter diagrams 

to allow any structure to be seen more clearly and for identifying possible nonlinear relationships (Everitt, 2002).

lithophilic spawner A fish species that requires gravel or 

cobble for nest construction and successful spawning.

percid A fish species belonging to the perch family (Percidae).

pool A relatively small portion of a stream reach with little 

velocity, commonly with water deeper than surrounding areas.

qualitative multihabitat (QMH) Different habitats identified 

in a reach from which fish and invertebrate samples are collected.

reach A length of stream that is chosen to represent a uniform set of physical, chemical, and biological conditions. It is 

the principal sampling unit for collecting physical, chemical, 

and biological data.

richest targeted habitat (RTH) A targeted habitat, where the 

taxonomically richest invertebrate community is theoreticallylocated, and where invertebrate samples are collected.

riffle A shallow part of the stream where water flows swiftly 

over completely or partially submerged coarse substrate that 

produces turbulence of the water surface which enhances aeration.

run A relatively shallow part of a stream with moderate 

velocity and little or no surface turbulence. 

stage The height of a water surface above an established 

datum; same as gage height.

stormwater runoff Rainwater or snowmelt that is transported 

to streams by overland flow or drains.

transect A line across a stream perpendicular to the flow 

and along which measurements are made, so that morphological and flow characteristics along the line are described bank 

to bank.

trophic guild Group of species that prey or forage on the 

same food resources.

voucher collection An assortment of preserved specimens 

representing the fauna that was sampled. It is used for validating taxonomic identifications and documenting spatial and 

temporal distribution and variation.

wadeable A stream that can be safely waded while effectively using sampling equipment. 

Glossary

24 Urban-Related Environmental Variables in the Fountain Creek Basin, Colorado
Printed on recycled paper