Water Budget for and Nitrogen Loads to 

Northeast Creek, Bar Harbor, Maine 

Water-Resources Investigations Report 02-4000 

Prepared in cooperation with the National Park Service 

U.S. Department of the Interior 

U.S. Geological Survey 
Cover: Aunt Betsey's Brook and Fresh Meadow during high water. 

(Photograph by Charles W. Culbertson) 
U.S. Department of the Interior 

U.S. Geological Survey 

Water Budget for and Nitrogen Loads to 

Northeast Creek, Bar Harbor, Maine 

By Martha G. Nielsen 

Water-Resources Investigations Report 02-4000 

Prepared in cooperation with the National Park Service 

Augusta, Maine 

2002 
U.S. DEPARTMENT OF THE INTERIOR 

GALE A. NORTON, Secretary 

U.S. GEOLOGICAL SURVEY 

Charles G. Groat, Director 

The use of firm, trade, and brand names in this report is for identification purposes 

only and does not constitute endorsement by the U.S. Geological Survey. 

For additional information write to: Copies of this report can be purchased 

from: 

District Chief U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

26 Ganneston Dr. Box 25286, Federal Center

Augusta, ME 04330 Denver, CO 80225

http://me.water.usgs.gov
CONTENTS 

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


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


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


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


Conceptual Model of the Water Budget and Nitrogen Inputs to the Northeast Creek/Fresh Meadow 


Estuary System..................................................................................................................................................... 5


Water Budget..................................................................................................................................................... 5


Nitrogen Inputs.................................................................................................................................................. 6


Methods of Data Collection ....................................................................................................................................... 7


Surface Water.................................................................................................................................................... 7


Ground Water.................................................................................................................................................... 9


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


Water Budget for the Northeast Creek/Fresh Meadow System................................................................................. 9


Estimation of Surface-Water Inflow ................................................................................................................. 9


Estimation of Precipitation Inputs..................................................................................................................... 13


Estimation of Evapotranspiration...................................................................................................................... 13


Estimation of Ground-Water Inputs.................................................................................................................. 14


Monthly Water Inputs and Surface-Water Outflows ........................................................................................ 15


External Nitrogen Loading to Northeast Creek ......................................................................................................... 17


Surface-Water Loading ..................................................................................................................................... 17


Water-Quality Data................................................................................................................................... 17


Estimation of Loads.................................................................................................................................. 21


Atmospheric Loading........................................................................................................................................ 26


Ground-Water Loading ..................................................................................................................................... 26


Tidal Loading .................................................................................................................................................... 27


Total External Nitrogen Loads.......................................................................................................................... 28


Summary and Conclusions ........................................................................................................................................ 28


References Cited ........................................................................................................................................................ 31


LIST OF FIGURES 

1. Map showing location of the Northeast Creek/Fresh Meadow study area, Bar Harbor, Maine ..................... 3


2. 	 Schematic diagram showing conceptual hydrologic budget for the Fresh Meadow/Northeast 


Creek system ............................................................................................................................................. 5


3. Schematic diagram showing conceptual model of nitrogen inputs to Northeast Creek.................................. 6


4. Map showing locations of data-collection sites in the Northeast Creek/Fresh Meadow study area ............... 8


5. 	 Map showing locations of continuous-record streamflow-gaging stations used as index stations 


for MOVE.1 analysis................................................................................................................................. 10


Contents iii
LIST OF FIGURES—Continued 

6. 	 Graph showing estimated mean daily streamflow at the Lower Old Mill Brook gage, measured 

daily streamflow upstream at the Upper Old Mill Brook gage, and periodic measurements of 

streamflow at the Lower Old Mill Brook gage, April 1, 1999 to September 30, 2000 ............................. 12 

7. Graph showing monthly water budget for the Northeast Creek/Fresh Meadow system................................. 15 

8. 	 Graph showing monthly measured and 19-year average precipitation at the Acadia National 

Park National Atmospheric Deposition Program station, March 1999 to September 2000...................... 16 

9. 	 Graph showing relation of nutrient concentrations and streamflow in tributaries to 

Northeast Creek ......................................................................................................................................... 22 

10. 	 Graph showing seasonal nitrogen loads by tributary to Northeast Creek, April 1999 to 

September 2000 ......................................................................................................................................... 25 

11. 	 Graph showing monthly precipitation and wet deposition of atmospheric nitrogen on 

Northeast Creek, March 1999 to September 2000 .................................................................................... 27 

12. Graph showing seasonal nitrogen loads to Northeast Creek from all hydrologic sources.............................. 29 

LIST of TABLES 

1. Estimated 1981 and 1996 population in the Northeast Creek drainage basin, Bar Harbor, Maine............. 4 

2. 	 Surface-water monitoring locations, Northeast Creek/Fresh Meadow study area, April 

1999 to September 2000............................................................................................................................. 7 

3. 	 R-squared values for correlations between streamflow at index stations and monthly measurement 

stations, Northeast Creek/Fresh Meadow study area ................................................................................. 10 

4. 	 Estimated monthly surface-water inflows to the Northeast Creek/Fresh Meadow system, 

April 1999 to September 2000 ................................................................................................................... 13 

5. 	 Monthly estimated evapotranspiration and precipitation for the Northeast Creek/Fresh Meadow 

system, April 1999 to September 2000 ...................................................................................................... 14 

6. Water-quality and streamflow data used to estimate nitrogen loads to Northeast Creek ............................ 18 

7. 	 Equation coefficients used to calculate the natural logarithm of the load for each nitrogen 

species in each tributary basin to Northeast Creek .................................................................................... 21 

8. Nitrogen loading rates for inflow streams to Northeast Creek .................................................................... 23 

9. Seasonal loading ratios for surface-water and atmospheric sources to Northeast Creek ............................ 30 

iv Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
CONVERSION FACTORS, VERTICAL DATUM, AND OTHER ABBREVIATIONS 

Multiply By To obtain 

Length 

centimeter (cm) 0.3937 inch 

meter (m) 3.281 foot 

kilometer (km) .6214 mile 

millimeter (mm) .03937 inch 

Area 

square kilometer (km2) .3861 square mile 

Volume 

milliliter (mL) .0338 fluid ounce 

liter (L) .2642 gallon 

cubic meter (m3) 8.110 x 10-4 acre-foot 

cubic meter (m3) 35.31 cubic foot 

Mass 

milligram (mg) 3.527 x 10-8 ounce 

kilogram (kg) 2.205 pound 

kilogram per square kilometer per year (kg/km2/yr) 5.710 pound per square mile per year 

Flow Rate 

cubic foot per second (ft3/s) .02832 cubic meter per second 

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

°F = (1.8 × °C) + 32 

Sea level: In this report, “sea level” refers to the National Geodetic Vertical Datum of 1929 (NGVD 

of 1929)—a geodetic datum derived from a general adjustment of the first-order level nets of both 

the United States and Canada, formerly called Sea Level Datum of 1929. 

Altitude, as used in this report, refers to distance above or below sea level. 

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 

in micrograms per liter (μg/L). 

Other abbreviations used in this report: 

nm, nanometer 

Contents v 

Water Budget for and Nitrogen Loads to 

Northeast Creek, Bar Harbor, Maine 

by Martha G. Nielsen 

ABSTRACT 

The potential for nutrient enrichment to 

coastal estuaries on Mt. Desert Island, Maine, may 

affect the health of these important ecosystems at 

Acadia National Park. Inputs of water and nitrogen 

entering one of these coastal estuaries, Northeast 

Creek, and adjacent wetlands on Mt. Desert Island 

were quantified in a recent study conducted by the 

U.S. Geological Survey, in cooperation with the 

National Park Service. Streamflow and concentrations of nitrogen species in the four perennial 

streams entering the wetland/estuary system were 

measured monthly for 18 months to estimate loads 

and develop a water budget. Old Mill Brook was 

instrumented with a continuous-recording streamflow gage; the MOVE.1 record-extension technique was used with this and several other nearby 

continuous gages to estimate daily surface-water 

inflow to the wetland. Inflow from ungaged basins 

was estimated from the unit-area yield calculated 

from data obtained from the gaged basins. Precipitation data collected at the National Atmospheric 

Deposition Program (NADP) site at Acadia 

National Park Headquarters and the Acadia 

National Park weather station were used to calculate atmospheric inputs. Evapotranspiration from 

the wetland was calculated using Fennessey and 

Vogel’s regionalized multivariate regression 

model of Penman-Montieth evapotranspiration. 

Geologic data collected in the field and taken from 

published geologic maps indicate that ground 

water probably does not contribute significantly to 

the water budget of this wetland system. Surfacewater outflow from the wetland was not calculated 

because of the tidal nature of the outlet of the 

wetland and the difficulties associated with 

measuring flow in a tidal stream. 

The water-budget equation used in the analysis was used to calculate a residual term (interpreted to equal surface-water outflow plus or 

minus changes in storage plus errors in the other 

calculations) from surface-water inputs plus 

precipitation minus evapotranspiration. This 

residual term was larger than the calculated 

surface-water inflows in the fall, winter, and 

spring months, and probably consists of changes in 

storage and surface-water outflows. During the 

dry summer months when evapotranspiration was 

high, the residual term was smaller than surfacewater inflow. This may be explained by the reduction in storage in the wetland as a result of evapotranspiration. 

In this study, nitrogen (nitrate and total 

nitrogen) input loads were calculated with respect 

to Northeast Creek, rather than to the wetland, 

because the creek is more susceptible to ecological 

effects from development. Nitrogen loads were 

estimated from surface-water sources using the 

daily streamflow estimates calculated for the water 

budget and the monthly water-quality sampling 

data. Nitrate (as N) concentrations ranged from 

below detection (< 0.01 mg/L (milligrams per 

liter)) to 0.20 mg/L. Total nitrogen concentrations 

ranged from 0.19 to 0.98 mg/L. The rating-curve 

regression method was used to calculate daily 

loads from inflow streams. Average unit-area 

yields were used to estimate loads for the ungaged 

areas. Atmospheric inputs were calculated from 

the NADP nitrogen data. 

Nitrogen yields from the inflow streams 

generally were small compared to yields from 

Abstract 1 
streams in urbanized areas and otherwise highly 

affected streams elsewhere in the northeastern 

United States, where the median yield of total 

nitrogen is 520 kg/km2/yr (kilograms per square 

kilometer per year), and yields can exceed 

1,000 kg/km2/yr in the most urbanized watersheds. Nitrate yields from the Northeast Creek 

inflow streams ranged from 13 to 44 kg/km2/yr. 

Total nitrogen yields ranged from 130 to 

270 kg/km2/yr. Over the 18-month study period, 

the estuary received an estimated 5,900 kg (kilograms) of total nitrogen and 780 kg of nitrate. 

Atmospheric inputs (totaling 85 kg of nitrogen) 

represented only 1 percent of the total nitrogen 

load and less than 10 percent of the inorganic 

nitrogen load. 

INTRODUCTION 

Eutrophication of coastal estuaries is an important environmental concern along the eastern coast of 

the United States. Loads of nutrients, particularly 

nitrogen, to these estuaries have caused rapid shifts in 

plant communities (Harlin, 1995; Short and Burdick, 

1996; Valiela and others, 1978). As nitrogen loads 

increase, algae growth increases to the extent that 

rooted aquatic plants, such as seagrasses, cannot 

compete and die out, leaving an algae-dominated 

system. Experiments on estuaries and estuarine plants 

have shown that nitrogen is the limiting nutrient in 

these systems (Harlin, 1995; Harlin and Thorne-Miller, 

1981). Increases in loads of nitrate and ammonia have 

caused extensive growths of floating, mat-forming 

algae in estuaries that crowd out and shade the native 

rooted plants. Furthermore, when these algae die, they 

decompose and consume the available oxygen, causing 

a condition known as hypoxia, which can contribute 

further to habitat loss. Estuaries affected by eutrophication have been well-documented in North America, 

Australia, Italy, and elsewhere, including on Mt. Desert 

Island (Harlin, 1995; Kinney and Roman, 1998). The 

primary factor identified in these studies as contributing to eutrophication is nutrient enrichment from 

upland residential development (McClelland and 

Valiela, 1998; Valiela and others, 1992). 

Eutrophication of one coastal estuary (Bass 

Harbor Marsh) has been documented at Acadia 

National Park, on Mt. Desert Island in coastal Maine 

(Doering and others, 1995). The conversion of 

widgeon grass habitat to algae took place there even 

when the overall loading rate was considered relatively 

low (Kinney and Roman, 1998). Concerns about the 

potential for the development of eutrophic conditions 

in other, currently unaffected estuaries on Mt. Desert 

Island have arisen because of the rapid growth in residential development across the island during the late 

1990s. These residential developments are served by 

domestic septic systems, and nitrogen from the 

increasing number of these systems may affect the 

water resources of the island. In order to understand the 

possible effects of this development, the U.S. Geological Survey (USGS), in cooperation with the National 

Park Service, began a study of the largest estuarine 

wetland on Mt. Desert Island, the Northeast 

Creek/Fresh Meadow wetland, in 1999. The goals of 

the study were to develop a water budget for the area 

and to quantify hydrologic nutrient inputs to the system 

in order to evaluate the potential effect of increasing 

residential development in the uplands that drain into 

Northeast Creek. 

Purpose and Scope 

The Northeast Creek/Fresh Meadow estuarine 

wetland (referred to in this report as “the Northeast 

Creek/Fresh Meadow system”) includes a brackish 

tidal creek (Northeast Creek) referred to as “the creek” 

in this report, and a freshwater wetland (Fresh 

Meadow). This report describes the results of an investigation to develop a preliminary hydrologic budget for 

the Northeast Creek/Fresh Meadow system and to 

determine the flux of external nitrogen entering Northeast Creek. The study focused on the most readily 

determined aspects of the hydrologic budget of the 

system—surface-water inflows, atmospheric precipitation, and evapotranspiration. Nitrogen fluxes from 

surface-water inflows and atmospheric precipitation 

also were determined. Ground-water inflows also were 

considered. Data are presented for the period of study, 

from April 1999 through September 2000. 

Description of Study Area 

The Northeast Creek/Fresh Meadow system is 

located on the northern side of Mt. Desert Island, 

Maine (fig. 1). The outlet of Northeast Creek flows into 

Thomas Bay, and is constricted by the remains of an old 

rock dam and a bridge, which are at an elevation just 

slightly below mean high tide. Northeast Creek 

2 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Figure 1. Location of the Northeast Creek/Fresh Meadow study area, Bar Harbor, Maine. 

Introduction 3 
receives tidal input during most of the lunar cycle and 

often is highly stratified. Freshwater from the inflowstreams rides above the saltwater because of density 

differences. During large runoff events, the freshwater 

completely flushes the saltwater out of the estuary, only 

to be partially displaced again by saltwater at the next 

tidal maximum (unpublished data available at the U.S. 

Geological Survey office in Augusta, Maine). Because 

the tidal saltwater stays at the bottom of the creek, the 

submerged vegetation consists predominantly of salttolerant Ruppia maritima (widgeon grass) along most 

of its length. 

Four perennial streams and three intermittent 

streams feed the Northeast Creek/Fresh Meadow 

system. An area adjacent to the wetland does not 

contribute substantial channelized surface-water flow 

to the wetland or creek, but probably contributes 

shallow ground-water flow to the wetland. The four 

perennial streams and their drainage areas (fig. 1) are, 

from largest to smallest, Stony Brook (6.73 km2

), Old 

Mill Brook (6.13 km2

), Aunt Betsey’s Brook 

(1.62 km2

), and French Hill Brook (1.40 km2). The 

drainage basins of the three intermittent streams, 

including Liscomb Brook, have a total area of 

3.40 km2

. Uplands immediately surrounding the 

wetland that are not drained by channelized surface 

runoff total 4.74 km2 in area. The Fresh Meadow 

wetland covers an area of 1.85 km2

. The surface area 

covered by Northeast Creek itself (upstream from 

Route 3) is estimated to be 0.14 km2

. 

One potentially important factor in the contribution of nitrogen to the system is the density of population in the basin. The population of the study area in 

1981and 1996 (the only two years before the study 

when population data could be estimated in each basin) 

was estimated to be 246 and 365, respectively (table 1). 

Since 1996, residential growth in the study area accelerated further (unpublished records, Town of Bar 

Harbor, Maine). The 1981 estimate is based on the 

number of houses visible on the Salisbury Cove, 

Maine, 1:24,000-scale topographic map and occupancy 

data (1.55 persons per household) for Hancock County, 

Maine (U.S. Bureau of the Census, 1992). During the 

1990s, this area was one of the last undeveloped nonpark areas on Mt. Desert Island and was a desirable 

location for new houses. The 1996 estimate is based on 

the number of houses visible on 1996 digital orthophoto quadrangles. Some of these houses are occupied 

only seasonally, so the year-round population probably 

is somewhat lower. Most of the population growth in 

the study area has been in the western and southern 

parts—French Hill Brook, Old Mill Brook, and the 

southern unnamed tributary to Northeast Creek. The 

population of Stony Brook Basin has remained fairly 

stable. Because many houses there were built before 

the 1980s, they utilize older septic technology than that 

used when the newer houses in other parts of the study 

area were built. 

Table 1. Estimated 1981 and 1996 population in the Northeast Creek drainage basin, Bar Harbor, Maine 

[Data from 1981 U.S. Geological Survey topographic map, 1996 U.S. Geological Survey digital orthophoto quadrangle, and U.S. Bureau of the Census, 1992] 

1981 1996 

Drainage basin Estimated number Estimated number Estimated number Estimated number 

of houses of people of houses of people 

Aunt Betsey's Brook

French Hill Brook

Stony Brook

Old Mill Brook

Unnamed tributary south

Unnamed tributary north

Liscomb Brook

Ground-water area

Total area, Northeast Creek 

7 11 12 19 

5 8 24 37 

55 86 59 92 

16 25 35 55 

20 31 33 51 

3 5 2 3 

15 23 24 37 

37 57 47 71 

158 246 236 365 

basin 

4 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Most of the study-area drainage basin is forested. 

Portions of Old Mill Brook, Stony Brook, and French 

Hill Brook were burned in a severe forest fire in 1947. 

A few fields are scattered throughout the drainage area. 

Some of these are grazed by cattle and horses, but most 

are in hay production. 

CONCEPTUAL MODEL OF THE WATER 

BUDGET AND NITROGEN INPUTS TO THE 

NORTHEAST CREEK/FRESH MEADOW 

ESTUARY SYSTEM 

Water Budget 

A conceptual model of the water budget for the 

Northeast Creek/Fresh Meadow system (fig. 2) 

includes inputs from surface-water runoff (QS-in), 

precipitation (P), ground water (QGW), and tidal 

inflows (QT-in). The ground-water inputs can be 

divided into deep ground-water flow from the fractured-bedrock aquifer recharged in the upland parts of 

the basin (QGWdeep) and shallow ground-water flow 

(QGWshallow) from the nearby lowlands that are not 

drained by channelized surface-water flows. This division is required because the deep and shallow groundwater systems are separated by a marine clay layer, the 

Presumpscot Formation, which is widespread in 

lowland areas in coastal Maine (Bloom, 1960; 

Thompson and Borns, 1985), including the study area 

(Hansen, 1980). Outputs from the wetland system 

include surface-water outflows (QS-out), ground-water 

outflows (QGW-out), tidal outflows (QT-out) and evapotranspiration (ET), plus or minus changes in storage in 

the wetland system. The water-budget equation for the 

wetland system is written as follows: 

∆Storage + Q(S-out) + Q(T-out) + ET + Q(GW-out)= 

Q(S-in) + Q(T-in) + Q(GWdeep) + Q(GWshallow) + P .(1) 

Figure 2. Conceptual hydrologic budget for the Fresh Meadow/Northeast Creek system. 

Conceptual Model of the Water Budget and Nitrogen Inputs 5 
Nitrogen Inputs 

A complete nitrogen budget for the Fresh 

Meadow/Northeast Creek system would include all 

hydrologic inputs, biological inputs, and biologically 

mediated chemical transformations. Because of budget 

and time constraints, the scope of this investigation was 

limited to external hydrologic inputs of nitrogen to 

Northeast Creek (fig. 3). These nitrogen sources 

include precipitation on the creek surface (NPrecip.

), 

surface-water inputs (NSW), and ground-water inputs 

(NGW). As in the water budget, the ground-water inputs 

are classified into deep ground-water infiltration 

through the streambed (NGW-deep) and shallow infiltration of ground water from the peat soils of the Fresh 

Meadow wetland into the creek (NGW-marsh). The 

determination of tidal inputs (NT) was beyond the 

scope of this study, although they are recognized as 

potentially important to the nitrogen budget of the 

creek as a whole. 

Figure 3. Conceptual model of nitrogen inputs to Northeast Creek. 

6 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
METHODS OF DATA COLLECTION 

Surface Water 

Five streamflow-gaging/water-quality stations 

(fig. 4) were established in the Northeast Creek 

drainage basin to determine the volume of water and 

mass of nitrogen entering the Fresh Meadow wetland 

system, including Northeast Creek (table 2). One 

station (Old Mill Brook at Old Norway Drive) was 

established to continuously record streamflow data. 

Partial-record stations, established at the mouths of the 

four perennial streams entering the Fresh Meadow 

system, were measured for streamflow and sampled for 

water quality monthly. All streamflow data were 

collected using USGS methods described in Carter and 

Davidian (1968) and in Rantz and others (1982). 

Stage at the continuous-record station 01022800 

was recorded at 15-minute intervals using an electronic 

data logger connected to a pressure transducer. Streamflow measurements were used to develop a rating 

curve, which gives the streamflow associated with a 

particular stage. The daily mean streamflow was 

computed as the arithmetic mean of the streamflows 

associated with the recorded stages for each day. The 

data for periods of ice (30 days) and 56 days of missing 

record were estimated using standard USGS methods 

(Stewart and others, 2001). Data collected at the 

partial-record sites consisted of periodic (monthly) 

measurements of stage and streamflow. A complete 

tabulation of the daily and monthly discharge data are 

published separately in Nielsen and others (in press). 

Field parameters (dissolved oxygen, pH, temperature, and specific conductance) were measured at the 

time of sample collection using either a Yellow Springs 

Instruments 600XL or a Hydrolab minisonde multiparamter probe. Measurements were made by 

immersing the probe directly in the stream. All probes 

were calibrated at least twice a day. 

Water-quality samples were collected monthly 

from April 1999 through September 2000 at each of the 

stations in table 2. (A complete listing of all the water 

quality data collected can be found in Nielsen and 

others (in press)). Unfiltered grab samples were 

collected by rinsing the sample bottles three times in 

the stream water, then filling each directly from the 

stream. Two 500-mL nalgene bottles were used to 

collect water for nitrogen analysis, and each was filled 

to the top and put on ice. Samples were kept on ice until 

delivered to the laboratory within 48 hours of collection. 

In the laboratory, the contents of one sample 

bottle were filtered through a 0.4-micron filter and split 

for analyses for nitrate and ammonium. The ammonium samples were acidified, stored in the dark at 4°C, 

and analyzed using a colorimetric method at 660 nm on 

an autoanalyzer within 28 days. Nitrate samples were 

stored in the dark at 4°C and analyzed by means of ion 

chromatography using a method based on U.S. Environmental Protection Agency (USEPA) method 300.0 

within 7 days (Morrison, 1989). The other bottle was 

stored unfiltered in the dark at 4°C and analyzed within 

28 days for total nitrogen using an alkaline persulfate 

digestion followed by colorimetric determination at 

540 nm on an autoanalyzer using a method based on 

USEPA method 600/4-87/026, 1987, section 18 

(Morrison, 1989). Samples also were analyzed for 

other constituents, including chloride (see Nielsen and 

others (in press)). 

Table 2. Surface-water monitoring locations, Northeast Creek/Fresh Meadow study area, April 1999 to 

September 2000 

[km2, square kilometer] 

Station 

number Station name Drainage area (km2) Type of data collected for this study1 

01022800 Old Mill Brook at Old Norway Drive 3.91 Continuous stage and periodic streamflow 

01022805 Old Mill Brook at Crooked Road 6.13 Monthly streamflow and water quality 

01022810 Stony Brook at Hamilton Pond 6.73 Monthly streamflow and water quality 

01022815 Aunt Betsey’s Brook 1.62 Monthly streamflow and water quality 

01022817 French Hill Brook 1.40 Monthly streamflow and water quality 

1

Additional data may have been collected as part of other studies at these sites. 

Methods of Data Collection 7 
Figure 4. Locations of data-collection sites in the Northeast Creek/Fresh Meadow study area. 

8 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Ground Water 

Ground water in the bedrock aquifer surrounding 

the Northeast Creek/Fresh Meadow system discharges 

to a surface-water body near the study area. Evaluating 

whether or not the aquifer discharges to Northeast 

Creek and the Fresh Meadow wetland is crucial to 

understanding the potential contribution of nitrogen 

from ground water to the Northeast Creek/Fresh 

Meadow system. The creek and wetland would be a 

natural discharge point for the aquifer if the surficial 

materials beneath the wetland and creek bottom are 

hydrologically connected to the aquifer. If the surficial 

materials act as a barrier to ground-water flow, 

discharge from this aquifer must occur elsewhere, 

perhaps directly into Thomas Bay or Eastern Bay, 

which are the water bodies of lowest hydraulic head in 

the area. Available maps of surficial geology (Hansen, 

1980; Gilman and others, 1988) indicate that a marine 

clay layer (the Presumpscot Formation) that would 

inhibit the discharge of deep ground water to the 

system likely is present beneath it. 

In order to confirm the presence of the Presumpscot Formation along the bottom of Northeast Creek, a 

coring survey was completed in July 2000. Fifteen 

cores were collected to determine the composition of 

the bottom material. A 5-cm-diameter stainless-steel 

bucket auger attached to as many as four 1.2-m sections 

of threaded pipe was used to core into the streambed. 

Cores were collected by standing at the water’s edge 

and coring into the bottom of the creek 15 to 25 cm 

from the bank, where the water generally was less than 

20 cm deep. The maximum core depth was 5.2 m below 

the water surface. Global-positioning system (GPS) 

coordinates were recorded in the field and locations of 

the coring sites (fig. 4) were recorded on a topographic 

map. 

Precipitation 

Inorganic nitrogen loads from precipitation were 

calculated using data from the National Atmospheric 

Deposition Program (NADP) station (ME98) at Acadia 

National Park, located just outside the boundary of the 

study area (fig. 4). The station, operated by the 

National Park Service, is located near the park administrative headquarters at an altitude of 129 m. Weekly 

concentration data for ammonia and nitrate and sample 

and precipitation volumes are screened for completeness as part of the NADP program (National Atmospheric Deposition Program, 1999). Data for the period 

from April 1999 through September 2000 were 

obtained. 

WATER BUDGET FOR THE NORTHEAST 

CREEK/FRESH MEADOW SYSTEM 

Understanding how water enters and leaves the 

Northeast Creek/Fresh Meadow system is important as 

a key to understanding how water-borne nitrogen 

enters the system. The volumes of the following 

primary non-tidal sources of water to the system were 

quantified: surface-water inflows, precipitation, evapotranspiration, and deep ground-water inflows. Surfacewater outflows were not measured because of the tidal 

nature of the outlet of Northeast Creek. Tidal streams 

are difficult to gage because the stage-discharge relation cannot be easily defined. 

Estimation of Surface-Water Inflow 

Surface-water inflows were calculated using the 

monthly streamflow measurements and applying a 

record-extension technique to estimate daily flows for 

the four measured tributaries. Several methods of 

streamflow record extension have been proposed or 

used in the past, including graphical correlation 

(Searcy, 1959) and linear regression (Hirsch, 1982). 

The method used in this study is known as MOVE.1 

(Maintenance of Variance-Extension, type 1), or the 

line of organic correlation (Helsel and Hirsch, 1992). 

The MOVE.1 technique produces streamflow estimates at the partial-record station with a statistical 

distribution similar to that expected if the streamflow 

had actually been measured (Helsel and Hirsch, 1992). 

The MOVE.1 technique was used to estimate 

mean daily flows for the period April 1, 1999 to 

September 30, 2000 at each tributary stream. This technique uses log-transformed streamflow data from the 

tributary streams, where individual monthly measurements were made (fig. 4), and data from one or more 

continuous-record index stations (fig. 5). The individual streamflow measurements made at the inflow 

streams were compared to the daily mean flows at five 

index stations (the continuous-record gages on upper 

Old Mill Brook, Cadillac Brook, and Upper Hadlock 

Brook (all on Mt. Desert Island), and those on East 

Bear Brook and West Bear Brook (located on the mainland)). A correlation coefficient was calculated for 

each index-station/inflow-stream pair. R-squared 

values from these correlations (table 3) were used to 

select which index station(s) to use to estimate mean 

daily flows for each tributary stream. 

Water Budget for the Northeast Creek/Fresh Meadow System 9 
Because streamflow data are highly skewed, a 

log10 transformation is commonly done to linearize the 

data. Then, the means ( Y and X ) and standard deviations (Sy and Sx) of the logs of the concurrent streamflow data are calculated. The MOVE.1 equation is then 

written as follows: 

ˆ where Yi 

Y 

Sy 

Sx 

Xi 

X 

S 

Yˆ 

i = Y +

S

y (Xi − X ) x (1) 

is the estimated daily streamflow at the 

periodic-measurement site for day i, 

is the mean of the periodic 

measurements, 

is the standard deviation of the 

periodic measurements, 

is the standard deviation of the daily 

streamflows at the index station, 

is the mean streamflow on day i for the 

index station, and 

is the mean of the daily flows at the index 

station for the same days as those at the 

periodic-measurement station. 

Estimates of streamflow for the partial-record station 

were computed by entering known logarithms of the 

daily streamflow at the continuous-record station (Xi

) 

into the equation and then transforming the estimates 

Figure 5. Location of continuous-record streamflow-gaging Yˆ 

i from logarithms back into the original units. stations used as index stations for MOVE.1 analysis. 

Table 3. R-squared values for correlations between streamflow at index stations and monthly measurement stations, 

Northeast Creek/Fresh Meadow study area 

[Bold numbers indicate index station used to calculate daily flows for each monthly measurement station] 

Monthly Index station 

measurement 

station 

Upper Old Mill Cadillac Brook Upper Hadlock East Bear Brook West Bear Brook Brook Brook 

Lower Old Mill 

Brook 

0.92 0.66 0.92 0.89 0.85 

Aunt Betsey’s 

Brook 

0.95 0.39 0.68 0.87 0.79 

French Hill Brook 0.97 0.61 0.91 0.96 0.88 

Stony Brook 0.88 0.54 0.68 0.88 0.81 

10 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
The two index stations with the highest correlation coefficients were used to estimate flow in each 

inflow stream. Although the correlation of all stations 

with Old Mill Brook was good, correlations with some 

other basins also were good—in some cases equally so. 

Using both index stations that correlated well to each 

stream increased the robustness of the calculation. A 

plot of the measurements against the daily mean flows 

at the selected index stations also was evaluated for 

goodness-of-fit, to make sure that the relation between 

the inflow site and the selected index sites was appropriately linear. A weighting procedure (described 

below) was used to calculate the final daily flows at 

each inflow stream from the estimates of daily flow at 

the two best-fit index sites. 

The weighting procedure was as follows: 

Residual squared errors (rse) from the correlations for 

the best index stations for each site were compared, and 

the site with the lower rse was assigned to have weight 

W1. The other index station was assigned weight W2, 

such that 

W1 = 1 − [(rse1 ( rse1 + rse2 )] , and (2) 

W2 = 1 −W1 (3) 

The weighted average log10 flow (F) for each 

tributary stream was calculated using the log flow estimated from index station 1 (F1) and the log flow estimated from index station 2 (F2), 

F = W1 F1 +W2 F2 (4) 

Finally, daily mean streamflow for each inflow 

stream was calculated by taking the inverse log of F, 

Q = 10F 

(5) 

The goodness-of-fit for the relation between 

Lower Old Mill Brook and Upper Hadlock Brook was 

very good for the range of paired data. However, when 

the log of the daily mean flow (in cubic feet per second) 

of Upper Hadlock Brook rose above 0.45, which was at 

the upper end of the range of paired data, the predicted 

flows at Lower Old Mill Brook appeared to be much 

higher than seemed hydrologically reasonable. This 

unpredicted effect indicated that whereas the available 

data did not show any deviation in flows between the 

sites, Upper Hadlock Brook behaved very differently at 

high flows than Old Mill Brook. Therefore, when the 

log of the Upper Hadlock Brook daily mean flows rose 

above 0.45, values for the daily flows at Lower Old 

Mill Brook were derived solely from those at Upper 

Old Mill Brook. 

The estimated daily flows for the Lower Old Mill 

Brook station are plotted in figure 6 as an example of 

the method results. Actual measurements also are 

shown for comparison with the estimated daily flows. 

The estimated flows generally closely match the 

measured flows. Differences may not represent errors 

in the estimation, but rather reflect the difference 

between an instantaneous flow measured when the 

stage was rising or falling quickly and the average flow 

for that day. Flows during the summer of 1999 generally went to zero, or near zero, in all the streams. This 

period was one of pronounced drought in this area, with 

very little rainfall from May through mid-September. 

The estimated daily flows from each of the four 

measured tributaries were normalized by drainage area 

and averaged to obtain an average daily flow per square 

kilometer of drainage basin in the study area for each 

day. These daily averages were applied to the drainage 

areas of the three unmeasured tributary basins to estimate daily inputs to the system. 

After the daily flows were calculated, monthly 

inflows to the Northeast Creek/Fresh Meadow system 

were calculated (table 4). Very low runoff volumes 

entered the system during the summer of 1999 (especially July and August), because precipitation during 

that period was much lower than average. Much higher 

amounts of runoff in September and October of 1999 

were the result of two fall hurricanes. Winter runoff 

volumes remained high, because, unlike many continental parts of the United States, this area can experience winter storms that result in large runoff events. 

Water Budget for the Northeast Creek/Fresh Meadow System 11 
Figure 6. Estimated mean daily streamflow at the Lower Old Mill Brook gage, measured daily streamflow upstream 

at the Old Mill Brook gage, and periodic measurements of streamflow at the Lower Old Mill Brook gage, 

April 1, 1999 to September 30, 2000.

12 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Table 4. Estimated monthly surface-water inflows to the Northeast Creek/Fresh Meadow system, April 1999 to 

September 2000 

[Values are in thousands of cubic meters] 

Surface-water inflow 

Month Total 

surface-water 

inflow 

Aunt 

Betsey’s 

Brook 

French Hill 

Brook Stony Brook Old Mill Brook 

Ungaged 

streams 

Apr. 1999 768 38.8 69.7 303 225 131 

May 1999 520 21.0 38.6 197 180 83.3 

June 1999 95.0 3.14 5.98 45.9 25.5 14.4 

July 1999 18.5 0.40 0.77 9.72 5.04 2.57 

Aug. 1999 2.05 0.08 0.03 1.29 0.38 0.27 

Sept. 1999 616 34.9 59.5 190 224 108 

Oct. 1999 1,162 63.2 108 377 413 201 

Nov. 1999 1,562 88.7 152 508 538 275 

Dec. 1999 1,821 114 193 591 593 330 

Jan. 2000 1,102 65.0 110 369 362 196 

Feb. 2000 1,430 83.0 140 428 526 253 

Mar. 2000 2,497 153 263 803 828 451 

Apr. 2000 2,571 164 269 723 948 467 

May 2000 1,420 80.4 138 485 467 249 

June 2000 293 13.4 24.8 139 66.9 48.4 

July 2000 171 4.48 8.21 55.4 78.2 24.9 

Aug. 2000 20.5 0.34 0.69 10.4 6.32 2.75 

Sept. 2000 29.5 0.44 0.85 10.9 13.4 3.93 

Estimation of Precipitation Inputs 

Monthly precipitation volumes for the Fresh 

Meadow/Northeast Creek system were calculated for 

the wetland area using the weekly precipitation 

volumes from the NADP loading data (table 5). Input 

volumes in thousands of cubic meters (1,000 m3

) (table 

5) were calculated by multiplying the monthly precipitation by the area of the wetland (1.85 km2

). (NWS 

precipitation data also were available, but the NADP 

data were used to retain consistency between the 

precipitation volumes and precipitation loads.) Weeks 

that overlapped months were assigned to the month 

with the greatest number of days. Precipitation inputs 

were not calculated for the contributing drainage basins 

to the wetland, because the surface-water runoff 

volumes account for this. 

Estimation of Evapotranspiration 

Evapotranspiration (ET) was calculated for the 

Fresh Meadow wetland using a multivariate regression 

model developed by Fennessey and Vogel (1996) of 

Penman-Montieth ET developed for the northeastern 

United States. Input parameters for the model include 

average annual temperature, average monthly temperature, longitude, and elevation. An unlimited moisture 

supply (as in a wetland) is assumed in the model. 

Monthly ET was estimated using NWS temperature 

data for the Acadia National Park weather station for 

1999 and 2000 (table 5). As for the precipitation estimates, each monthly ET rate in centimeters per month 

was multiplied by the wetland area to estimate monthly 

volumes in thousands of cubic meters. Considerably 

cooler and wetter conditions during the summer of 

2000 than during the summer of 1999 resulted in lower 

ET rates for the second summer of the study. 

Water Budget for the Northeast Creek/Fresh Meadow System 13 
Table 5. Monthly estimated evapotranspiration and precipitation for the Northeast Creek/Fresh Meadow 

system, April 1999 to September 2000 

[mm/d, millimeters per day; m3/mo, cubic meters per month; cm/mo, centimeters per month] 

Evapotranspiration Precipitation 

mm/d m3 Month /mo

(in thousands) cm/mo m3/mo (in thousands) 

Apr. 1999 2.16 120 1.1 20.7 

May 1999 3.20 184 7.7 142 

June 1999 4.14 230 4.6 86.0 

July 1999 4.46 255 3.8 69.5 

Aug. 1999 3.94 226 3.6 67.2 

Sept. 1999 2.84 158 21.2 392 

Oct. 1999 1.73 99.2 14.8 274 

Nov. 1999 1.04 57.5 15.7 290 

Dec. 1999 0.82 46.9 13.8 255 

Jan. 2000 0.98 56.4 12.6 233 

Feb. 2000 1.30 67.5 7.3 135 

Mar. 2000 1.78 102 9.1 169 

Apr. 2000 2.29 127 22.0 407 

May 2000 2.77 159 13.3 246 

June 2000 3.13 174 6.2 115 

July 2000 3.26 187 9.7 180 

Aug. 2000 3.06 175 3.6 67.0 

Sept. 2000 2.54 141 8.8 162 

Estimation of Ground-Water Inputs 

Sediment cores were collected at 15 locations in 

Northeast Creek and Aunt Betsey’s Brook to determine 

the composition of the bottom material underlying the 

peat and the bottom of the creek (fig. 4). A blue pebbly 

clay layer was encountered under the peat in all the 

cores where the peat was shallow enough for the coring 

device to penetrate the bottom. The peat ranged in 

thickness from approximately 1.25 m to more than 5 m. 

The peat was more than 5 m thick (the maximum depth 

of the instrument) in five samples; small globules of 

clay were encountered near the bottom in several of 

these cores. On the basis of the coring survey and 

published surficial-geology maps (Hansen, 1980; 

Gilman and others, 1988), the Presumpscot Formation 

clay layer appears to be continuous below the peat and 

to provide an effective barrier to deep ground-water 

flow from the bedrock aquifer. 

Shallow ground-water inflow is another source 

of water to the wetland. A 4.74-km2 upland area adjacent to the wetland is not drained by channelized 

streams. Some of this area is underlain by Presumpscot 

Formation clay, some by shallow bedrock, and some by 

till. The areas underlain by till and clay probably 

contribute shallow ground-water flow to the wetland. 

The areas underlain by shallow bedrock, however, may 

contribute surface flow to the wetland and groundwater flow to the deeper bedrock aquifer. 

14 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Without specific water-level data and data on the 

hydraulic properties of the earth materials, estimation 

of shallow ground-water inflows for all months of the 

study would be difficult if not impossible. Streamflow 

data, however, can be used during periods of base flow 

to roughly estimate shallow ground-water input to the 

wetland for the same time period. During the summer 

months, the median daily flow for a given month was 

assumed to represent base flow—that is, ground-water 

discharge. The monthly base-flow volume (per unit 

area) was averaged for the two smaller basins (Aunt 

Betsey’s and French Hill Brooks), because the surficial 

materials in these basins are similar to those in the areas 

contributing shallow ground-water flow to the wetland. 

These monthly discharge rates were applied to the 

upland areas for the summer months (June through 

September) of each year for comparison with other 

sources of water to the wetland. If 75 percent of the 

4.74-km2 upland area is underlain by till or clay, 

summertime shallow ground-water seepage to the 

wetland may range from 33 m3/mo (for the driest 

month, September 1999) to 6,100 m3/mo (for June 

2000). These numbers are lower than any of the other 

water inflows calculated and are very small compared 

to the total water flux of the wetland. 

Monthly Water Inputs and Surface-Water 

Outflows 

After surface-water inflows, precipitation, and 

evapotranspiration are taken into account, the residual 

of the water budget is assumed to be net surface-water 

outflow plus or minus changes in storage in the wetland 

(fig. 7). The bulk of the residual is assumed to be net 

surface-water outflow. Total surface-water outflow (as 

opposed to net outflow) includes water that flowed in 

with the preceding tide, and this volume was not calculated. Deep ground-water inflows and outflows are 

assumed to be negligible, as the sediments underlying 

the wetland are not likely to transmit significant flows 

from the deeper aquifer below. Shallow ground-water 

inflows are not directly accounted for, but also are 

assumed to be small in relation to streamflows. 

Figure 7. Monthly water budget for the Northeast Creek/Fresh Meadow system. 

Water Budget for the Northeast Creek/Fresh Meadow System 15 
As figure 7 indicates, the magnitudes of the 

surface-water inflows and the residual (which is 

assumed to be surface-water outflow in most months) 

are similar. One way to evaluate the possible magnitude of surface-water outflows is to make some estimates of changes in storage. Changes in storage are 

assumed to be greatest when the surface of the wetland 

floods and holds water, and when water is removed 

from the peat by ET during the summer. If flooding 

during a spring month resulted in a 10-cm blanket of 

water over the whole wetland surface (which is similar 

to conditions observed in the field), the change in 

storage for that rise might be +185,000 m3. During the 

fall and spring, that amount would represent 5 to 

10 percent of the total residual. If, on the other hand, 

during the summer, the water surface in the peat 

dropped by 20 cm during a month (which is greater 

than any drop we observed from casual observation in 

the field), the resulting change in storage would be 

approximately –150,000 m3

 (assuming an effective 

porosity of 0.4 for the peat). This amount could account 

for 50 to 100 percent of the total residual during the 

summer. 

From September 1999 to May 2000, the residual 

was larger than the surface-water inflows. Whereas 

some of the residual undoubtedly represents changes in 

storage, the general pattern during this time was that 

surface-water outflows were somewhat larger than 

surface-water inflows. From June 1999 through Aug. 

1999 and Aug. 2000, the residual term was negative, 

which is consistent with a loss of water from the 

wetland as a result of ET and, perhaps, drainage of the 

peat. During these months, net surface-water outflow 

probably was very small. 

Because tidal flows were not measured, the relative magnitude of freshwater inflows and tidal flows to 

the system is unknown. Salt-tolerant plant species 

generally are confined to areas close to the banks of 

Northeast Creek; indicating that saltwater from tidal 

inflows does not inundate large areas of the wetland on 

a regular basis and generally is confined to the creek 

itself. During the hottest and driest months of 1999, 

when the residual of the water budget was negative, 

tidal flows may have come in and been partially 

consumed by ET in the wetland. 

To compare the period of data collection with 

long-term patterns, actual monthly precipitation 

amounts (fig. 8) were compared to the 19-year averages (herein referred to as “normal”) for each month 

from the NADP station. The spring and summer of 

1999 were extremely dry (as noted earlier), and were 

followed by a very wet fall. Conditions during the 

winter of 1999–2000 were relatively normal, whereas 

the early spring of 2000 also was very wet compared to 

the 19-year average. Conditions during the summer of 

2000 were much closer to normal than those during the 

summer of 1999. 

Figure 8. Monthly measured and 19-year average precipitation at Acadia National Park National Atmospheric Deposition 

Program station, March 1999 to September 2000. 

16 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
EXTERNAL NITROGEN LOADING TO 

NORTHEAST CREEK 

In contrast to the water budget, the nitrogen load 

estimates focus on Northeast Creek itself. Potential 

sources of nitrogen to Northeast Creek that were 

considered in this study include precipitation on the 

creek surface, seepage of deep ground water, lateral 

seepage of ground water from the wetland sediments to 

the stream, streamflow, and tidal flows. On the basis of 

the results of the sediment-coring survey, loads from 

deep ground water are assumed to be negligible. 

Ground-water seepage of nitrogen from the marsh sediments was not measured in this study; however, conditions in the sediments are favorable for denitrification 

(C.W. Culbertson, U.S. Geological Survey, oral 

commun., 2001), and these inputs also are assumed to 

be small. Surface-water and precipitation loads are 

both described in detail below. 

Surface-Water Loading 

There are two basic methods of calculating 

nitrogen loads to a water body, both of which have 

some degree of uncertainty. The first method is to 

quantify and sum all sources of nitrogen in the watershed. This method is unreliable (Alexander and others, 

2001), because only a fraction of the total nitrogen 

released in a watershed reaches the receiving water 

body because of denitrification, storage, and biological 

utilization of nitrogen in the watershed. These transformations happen both at the watershed scale and at the 

stream-channel scale, and are very difficult to reliably 

quantify. 

In the second approach, which does not differentiate among sources, the nitrogen load in the water 

entering the receiving body is measured. Stream-monitoring data integrate the effect of all nitrogen supply 

and loss processes upstream from the measuring point, 

but measurements of flow and concentration would 

have to be made constantly to determine the load 

exactly. Commonly used statistical techniques can be 

used to convert periodic measurements of flow and 

concentration into estimates of daily flux. Loads of 

nitrogen entering Northeast Creek were calculated 

using this method, as the product of the volumes of 

water and nitrogen concentrations for all sources of 

flow to the creek. 

Water-Quality Data 

The monthly sampling program for the inflow 

streams resulted in a total of 62 water samples that were 

analyzed for nitrogen, 13 to 17 per site (table 6). French 

Hill Brook had the fewest samples (13), because it was 

dry during August and September of both years. A 

sample could not be collected from Stony Brook in 

September 2000 because a beaver dam upstream from 

the site prevented water from flowing past the collection point. 

Nitrate concentrations ranged from below detection (< 0.01 mg/L-N) to 0.200 mg/L-N. The smallest 

average nitrate concentrations were measured in Old 

Mill Brook, in which the median concentration was 

0.012 mg/L-N. Concentrations of nitrate were greatest 

in Stony Brook (median concentration 0.061 mg/L-N). 

Concentrations in French Hill Brook and Aunt Betsey’s 

Brook were intermediate (medians of 0.023 mg/L-N 

and 0.031 mg/L-N, respectively). 

Ammonia concentrations ranged from below 

detection (< 0.05 mg/L) to 0.29 mg/L. Most concentrations were below the detection limit, especially in Old 

Mill Brook. 

Total nitrogen concentrations ranged from 0.19 

to 0.98 mg/L, and were lowest in Old Mill Brook, with 

a median concentration of 0.013 mg/L. Median 

concentrations in Aunt Betsey’s Brook and French Hill 

Brook were both 0.04 mg/L. The median concentration 

of total nitrogen in samples from Stony Brook was 

0.074 mg/L. 

These concentrations are similar to concentrations found in the inflow streams to Bass Harbor Marsh 

by Doering and others (1995). In that study, nitrate 

(as N) concentrations ranged from <0.003 to 

0.29 mg/L. Mean concentrations for the five streams 

measured in that study ranged from 0.003 to 0.175 

mg/L. Ammonia concentrations ranged from 0.007 to 

0.13 mg/L, with mean concentrations of 0.014 to 0.029 

mg/L. Total nitrogen concentrations ranged from 0.058 

to 0.723 mg/L, with mean concentrations of 0.420 to 

0.59 mg/L for the five stations. 

External Nitrogen Loading To Northeast Creek 17 
-- -- -- -- -- 

-- -- -- -- -- 

Table 6. Water-quality and streamflow data used to estimate nitrogen loads to Northeast Creek [Numbers in smaller italics represent samples that may be contaminated with saltwater and were not used in the loading calculations. Values in bold are calculated v

ft3/s, cubic feet per second; μs/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; N, nitrogen; NH4, ammonia; NO3, nitrate; --, no data; <, l

18 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 

Stream Date Streamflow Specific NO3 Total N NH4 NH4 

(ft3/s) conductance (mg/L-N) (mg/L) (mg/L) (calculate

(μs/cm) (mg/L) 

Aunt Betsey's Brook 04/14/99 0.500 60.0 0.012 0.25 < 0.05 0.025 

05/12/99 .220 75 .023 .40 <.05 .025 06/15/99 .060 100 .081 .42 .11 .11 

07/13/99 .002 200 .116 .70 .24 .24 08/25/99 .000 253 .056 .56 .13 .13 09/21/99 .030 200 .092 .66 .08 .08 

10/21/99 .500 79.6 .014 .43 <.05 .025 

11/17/99 .930 61.3 .011 .35 <.05 .025 

12/14/99 1.590 51.5 .018 .31 <.05 .025 

01/11/00 6.880 53.5 .031 .30 <.05 .025 

02/16/00 1.210 89.8 .032 .24 <.05 .025 05/03/00 .520 6.7 .01 .36 <.05 .025 05/31/00 .350 64.4 <.01 .34 <.05 .025 06/27/00 .050 140 .04 .59 .17 .17 

08/02/00 .004 344 .07 .63 .29 .29 09/25/00 .020 254 .07 .60 .13 .13 

French Hill Brook 04/14/99 .820 32.8 .020 .27 <.05 .025 

05/12/99 .450 43 .026 .44 <.05 .025 06/15/99 .060 52 .093 .45 .06 .06 07/13/99 .006 79 .073 .47 .11 .11 08/25/99 .00 09/21/99 .00 10/21/99 1.130 51.6 .013 .46 <.05 .025 

11/16/99 2.140 44.8 .023 .40 <.05 .025 

12/15/99 2.250 36.3 .023 .35 <.05 .025 01/12/00 3.430 36.5 .023 .20 <.05 .025 02/17/00 2.320 42.2 .024 .21 <.05 .025 
-- -- -- -- -- 

-- -- -- -- -- 

-- 

Table 6. Water-quality and streamflow data used to estimate nitrogen loads to Northeast Creek—Continued 

[Numbers in smaller italics represent samples that may be contaminated with saltwater and were not used in the loading calculations. Values in bold are calculated v

ft3/s, cubic feet per second; μs/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; N, nitrogen; NH4, ammonia; NO3, nitrate; --, no data; <, l

NH4 

Stream Date Streamflow Specific NO3 Total N NH4 (calculate

(ft3/s) conductance (mg/L-N) (mg/L) (mg/L) (mg/L

(μs/cm) 

French Hill Brook, continued 05/02/00 1.030 33.1 0.01 0.27 < 0.05 0.025 

External Nitrogen Loading To Northeast Creek 

Old Mill Brook (Lower) 

Stony Brook 

05/31/00 .760 35.4 <.01 .31 <.05 .025 06/27/00 .070 51 .07 .40 .06 .06 

08/02/00 2.008 71.2 .09 .5 .11 .11 

08/21/00 .0009/25/00 .00

04/14/99 2.460 50 .051 .20 <.05 .025 

05/11/99 1.490 54 .012 .50 <.05 .025 

06/15/99 .270 68 .013 .22 <.05 .025 07/13/99 .050 80 .013 .37 <.05 .025 

08/25/99 .00 350 .007 .40 <.05 

09/20/99 1.000 110 .010 .62 <.05 .025 10/21/99 5.300 52.8 .007 .28 <.05 .025 

11/17/99 7.000 45.2 .004 .19 <.05 .025 

12/13/99 15.200 39.8 .016 .20 <.05 .025 

01/11/00 48.500 43.4 .058 .20 <.05 .025 

02/17/00 9.690 49.4 .042 .19 <.05 .025 05/03/00 2.240 5.9 <.01 .20 <.05 .025 06/01/00 .910 5.1 <.01 .28 <.05 .025 06/27/00 .330 79 <.01 .98 <.05 .025 08/02/00 2.054 86.0 <.01 .76 .05 .05 

08/21/00 2.128 75.8 .03 .76 <.05 .025 09/27/00 2.127 78.4 <.01 .73 <.05 .025 

04/14/99 2.290 61 .061 .35 <.05 .025 

05/11/99 1.540 66 .034 .52 <.05 .025 

06/16/99 .330 70 .083 .76 .05 .05 

19 
-- -- -- -- -- 

20 Table 6. 

Water-quality and streamflo

w data used to estimate nitrogen loads to Northeast Creek—Continued 

[Numbers in smaller italics represent samples that may be contaminated with saltwater and were not used in the loading calculations. Values in bold are calculated vft3/s, cubic feet per second; μs/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; N, nitrogen; N

H4, ammonia; NO3 Wat , nitrate; --, no data; <, l

er Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine NH4 

Stream Date Streamflow 

Specific NO3 Total N NH4 (calculate

(ft

3/s) conductance (mg/L-N) (mg/L) (mg/L) (mg/L) 

(μs/cm) 

Stony Brook, continued 07/13/99 0.160 72 0.072 0.59 < 0.05 0.025 

08/25/99 .001 81 .200 .62 

<.05 .025 

09/21/99 .340 77 .014 .70 

<.05 .025 

10/20/99 4.320 86.5 .052 .93 .24 .24 

11/16/99 1.300 65 .076 .67 .08 .08 

12/14/99 11.800 52.2 .082 .50 

<.05 .025 

01/11/00 17.000 54.8 .118 .50 .07 .07 

02/17/00 16.500 71.2 .149 .43 .07 .07 05/03/00 2.820 52.3 .01 .31 <.05 .025 06/01/00 3.030 54.4 <.01 .48 

<.05 .025 

06/27/00 .860 59 .04 .62 <.05 .025 08/01/00 .310 61.8 .08 .63 <.05 .025 08/22/00 .090 63.0 .11 .65 <.05 .025 09/25/00 3.000 

1If NH4 was < 0.05, an assumed value of 0.025 was used for the loading estimation. 2No flow measurement; flows assigned from MOVE.1 calculations. 3No flow due to beaver activity; could not sample.
-- --

--

-- -- --

-- --

-- -- --

--

-- -- --

--

-- -- -- --

-- -- --

--

--

--

--

--

--

Estimation of Loads 

Chloride-concentration and specific-conductance data indicated that some samples were collected 

after tidal inflow had reached upstream to that 

sampling site and, therefore, the nitrogen concentrations may reflect tidal input rather than runoff from the 

watershed. Five samples from Aunt Betsey’s Brook 

and one sample from Old Mill Brook were discarded 

from the load estimation calculations for this reason. 

Values for these samples are italicized in table 6. 

Several methods exist for the computation of 

surface-water loads to a given water body. Hodgkins 

(2001) compared methods for calculating loads from 

forested watersheds in the Northeast. These methods 

fall into one of three general categories—averaging 

methods, ratio methods, and regression methods. Of 

these, regression methods often provided the best estimates, if the assumptions of the regression were met for 

each individual stream. Even so, errors commonly may 

exceed 30 percent or more (Robertson and Roerish, 

1999). 

Regression methods can be used if the relation 

between concentration and streamflow is discernible. 

Plots of concentration against streamflow for nitrate 

and total nitrogen (fig. 9) do show a relation. The 

regression method was used to estimate nitrogen loads 

from Old Mill Brook, Stony Brook, Aunt Betsey’s 

Brook, and French Hill Brook. After these estimates 

were completed, an average nitrogen yield on an areal 

basis was computed and applied to the three ungaged 

tributaries to Northeast Creek. 

To compute the regression equations for each 

tributary, loads were computed for each set of concentration and streamflow data and then transformed to the 

natural log of the daily load. (In water-quality studies, 

concentrations and streamflows typically are log-transformed to normalize the data set.) Natural log of load 

was the dependent variable. Various combinations of 

the natural log of streamflow, the square of the natural 

log of streamflow, time, sine (time), and cosine (time) 

(representing seasonality) were tested using a load-estimation computer program to determine the best regression equations at each site. Equations were fit 

individually for each constituent at each stream 

(table 7). 

Table 7. Equation coefficients used to calculate the natural logarithm of the load for each nitrogen species in each tributary 

basin to Northeast Creek 

[Coefficients as determined from load estimation output, for the equation of the form ln(load) = b0 + b1 ln(flow) + b2 ln(flow)2 + b3 dectime + 

b4 sin(dectime) + b5 cos(dectime); values for constituents in italics based on calculated values shown in table 6; b, coefficient; LSA, log streamflow 

adjustment applied to logs of streamflow before applying equation; N, nitrogen; --, no coefficient used] 

Basin Constituent LSA 

Load calculation equation coefficients 

b0 b1 b2 b3 b4 b5 

Aunt Betsey’s Nitrate-N 0.69315 -2.7759 0.89651 0.19103 -0.56574 

Brook Total N .69315 -.04604 1.0006 .023159 -0.28724 -0.2838 

Inorganic N .69315 -2.1633 .78193 .12478 

Organic N .69315 -.19061 1.0732 -.37037 -.35137 

Stony Brook Nitrate-N -.63017 -.9920 1.1655 .11221 

Total N -.63017 1.8706 1.0844 -.19641 -.46823 -.26386 

Inorganic N -.63017 -.26065 1.1820 .083886 

Organic N -.63017 1.6300 1.1671 -.26218 -.61519 -.60094 

Old Mill Brook Nitrate-N -.19939 -2.5739 1.1772 

Total N -.19939 .43931 .81348 .36983 

Inorganic N -.19939 -1.3530 .93449 .039337 .31891 .25970 

Organic N -.19939 .10729 1.0059 .36438 -.54586 -.66633 

French Hill Nitrate-N .19845 -2.1327 -.53582 -.18040 .48500 2.0160 

Brook Total N .19845 .66276 1.0198 -.22755 -.41877 -.32648 

Inorganic N .19845 -1.3881 .23169 -.068059 .17224 .84521 

Organic N .19845 .54126 1.1363 -.2871 -.5184 -.50693 

External Nitrogen Loading To Northeast Creek 21 
Figure 9. Relation of nutrient concentrations and streamflow in tributaries to Northeast Creek. 

22 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
--

-- -- --

These regression equations were used to estimate daily loads of total nitrogen, nitrate (as N), inorganic nitrogen, and organic nitrogen for the four 

measured tributaries. Concentrations of ammonia were 

below the detection limit in a sufficient number of 

samples to violate the conditions of the regression 

method. In order to compare inorganic- to organicnitrogen sources, however, a gross assumption was 

made so that when the ammonia concentration was 

below the detection limit of 0.05 mg/L, half that value 

(0.025 mg/L) was used for the regression (table 6). This 

value was added to the nitrate concentration to obtain 

an “inorganic nitrogen” term. This inorganic nitrogen 

term was subtracted from the total nitrogen to obtain a 

rough estimate of the relative importance of inorganic 

and organic nitrogen entering the system. Daily loads 

of these “inorganic nitrogen” and “organic nitrogen” 

terms also were calculated. 

A range of regression diagnostics was performed 

to test the regression assumptions for each constituent 

in each tributary. Residual plots of concentration 

against streamflow were analyzed, and non-normality 

of the residuals was examined for each constituent with 

the Turnbull-Weiss Likelihood Ratio Normality Test 

statistic (Turnbull and Weiss, 1978). Residual plots did 

not exhibit any curvature or other characteristics that 

would violate the assumptions of the regression 

method. 

Daily mean streamflows calculated using the 

MOVE.1 method described earlier were applied to the 

regression equations for each constituent above. Daily 

loads were then summed to seasonal loads for the 

period April 1999 through September 2000. Generalizing the data to seasonal loads reduced the reliance on 

specific days or months of data for both the surfacewater and precipitation inputs (described later). 

Seasonal loads for the smaller, unmeasured tributaries 

were estimated on the basis of the average per-unit-area 

yields from the other four streams. 

An error analysis was not conducted. Alexander 

and others (2001) used a similar load-estimation procedure, and included an uncertainty analysis as described 

by Gilroy and others (1990). Their uncertainties in 

mean fluxes ranged from about 2 to 19 percent, but they 

note that prediction errors are larger in small basins 

with fewer water-quality samples (they used 374 sites 

with a mean of 90 samples each). Because of the small 

number of samples in the data set for Northeast Creek, 

the uncertainty in these calculations is expected to be 

much larger than 20 percent. 

Total loads for each tributary were summed for 

the 18-month study period to analyze differences in 

loading rates among streams (table 8). Because of the 

method used to estimate “inorganic” and “organic” 

nitrogen loads (described above), these numbers are 

intended as a rough estimate for purposes of comparing 

inorganic- to organic-nitrogen loads. Load is the 

amount of nitrogen leaving each basin; yield is the 

amount leaving each basin per unit area. 

Table 8. Nitrogen loading rates for inflow streams to Northeast Creek 

[Values in italics are intended as rough estimates for the purpose of comparing inorganic and organic nitrogen loads; 

km2

, square kilometer; kg/km2/yr, kilogram per square kilometer per year; N, nitrogen; NO3, nitrate; --, not calculated] 

Basin (km2) Total N NO3-N “Inorganic” 

N 

“Organic” 

N 

Old Mill Brook 6.13 1,400 140 300 1,100 

Stony Brook 6.73 2,700 460 800 1,900 

Aunt Betsey’s Brook 1.62 310 26 50 260 

French Hill Brook 1.40 490 39 50 440 

Total ungaged streams 3.40 990 110 200 790 

Total 19.3 5,890 775 1,400 4,500 

Area 

Estimated load over 18 months (kg) “Organic” N Yield (kg/km2/yr) 

(percent of 

Total N NO3-N total) 

79 150 15 

70 270 44 

84 130 13 

90 225 19 

190 22 

External Nitrogen Loading To Northeast Creek 23 
The data show very different loading functions 

for different basins. Stony Brook, whose drainage basin 

is only slightly larger than that of Old Mill Brook, had 

almost twice the total nitrogen load for the 

18-month period, and French Hill Brook had more than 

50 percent more total nitrogen load than Aunt Betsey’s 

Brook, despite its smaller drainage basin. Yields of 

total nitrogen range from 130 kg/km2/yr for Aunt 

Betsey’s Brook to 270 kg/km2/yr for Stony Brook. 

Alexander and others (2001) reported that the total 

nitrogen export from 374 streams in the United States 

resulted in estimates of total nitrogen yield to coastal 

estuaries ranging from 38 to 2,500 kg/km2/yr nationally. North Atlantic streams (from Maine to Chesapeake Bay) were determined to export a median 

520 kg/km2

/yr of total nitrogen. 

Eutrophication in estuaries is commonly caused 

by increases in the load of inorganic nitrogen (Kinney 

and Roman, 1998). Stony Brook contributed 59 percent 

of the total nitrate-N load to Northeast Creek, whereas 

Aunt Betsey’s Brook contributed only 3 percent. Yields 

of nitrate ranged from 11 to 46 kg/km2

/yr (as N). Loads 

of ammonia were not estimated because of small 

number of samples that contained detectable ammonia 

(the detection limit for ammonia is much higher than 

that for nitrate). 

The ratio of organic nitrogen to total nitrogen 

ranged roughly from 70 percent in Stony Brook to 

90 percent in French Hill Brook. Meyer and Likens 

(1979) reported on the net transformation of nutrients 

from inorganic forms to organic or particulate forms by 

instream processes, so this result was expected. Similarly, a study by Doering and others (1995) of nutrients 

in Bass Harbor Marsh found that dissolved inorganic 

nitrogen accounted for 5 to 35 percent of the total 

nitrogen load from freshwater sources. 

Reasons for differences in yields among watersheds have not been fully investigated, although some 

of the basin characteristics discussed earlier may be 

important factors. Stony Brook Basin has a larger 

population than the other basins, and homes there tend 

to be older, with older septic technology. It also is the 

only basin (besides the ungaged tributary between Old 

Mill Brook and French Hill Brook) with any appreciable agricultural activity (a horse farm). Finally, a 

large pond is directly upstream from the Stony Brook 

measurement site, and several older homes are located 

near the pond. The reasons for the higher nitrogen 

loading rates from French Hill Brook than from Aunt 

Betsey’s brook are unclear. The characteristics of their 

drainage basins are similar, but recent development 

patterns have not been fully quantified in either basin 

since 1996. Some of the responses of nitrogen to 

streamflow indicate the possible presence of a point 

source upstream from the sampling location on French 

Hill Brook. 

Differences in surface-water loads among the 

basins also may result from differences in the degree of 

nitrogen saturation in each watershed. Nitrogen saturation in forested watersheds occurs when the atmospheric supply outpaces the watershed’s internal 

demand for nitrogen. A watershed can absorb atmospheric nitrogen only to the extent to which watershed 

plants and microbes can utilize it. Factors that can lead 

to nitrogen saturation in forested watersheds include 

high rates of nitrogen deposition, advanced stand age, 

and large pools of soil nitrogen (Stoddard, 1994). The 

upper part of the Old Mill Brook watershed was burned 

in the Mt. Desert fire of 1947, and all the available 

atmospheric nitrogen may be consumed by the forest as 

it recovers from the fire, lowering the yield. 

Total nitrogen and nitrate-nitrogen loads by 

season and tributary stream are shown in figure 10. A 

strong seasonality, which is largely a function of the 

seasonality in streamflow, is evident. Surface-water 

loads are largest in the fall, winter, and spring, and are 

quite low in the summer. The dominance of Stony 

Brook in the total load is evident and holds for all 

seasons. Because of the large amount of precipitation in 

March 2000 and the comparatively small amount of 

precipitation in April to May 1999, the overall spring 

load for 2000 is much larger than the load for April– 

May 1999. Summertime loads also were smaller in 

1999 than in 2000, primarily because the lack of rainfall resulted in long periods of no surface-water inflow 

to Northeast Creek during the 1999 season. A similar 

lack of rainfall in September 2000 is reflected in the 

very small loads during that month as well. 

Although most of the nitrogen input to the 

system takes place outside the growing season, sequestration of nitrogen coming in during spring runoff may 

occur through remineralization and could provide a 

source of nitrogen that could be released internally 

during the growing season. There is evidence that this 

process occurs in Chesapeake Bay and several of its 

subtributaries (Doering and others, 1995). The hydrologic holding time for the Northeast Creek system is 

24 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Figure 10. Seasonal nitrogen loads by tributary to Northeast Creek, April 1999 to September 2000. 

External Nitrogen Loading To Northeast Creek 25 
very short—water flowing in from the tributaries exits 

in a matter of hours to days (depending on surfacewater inflow rates), because of its short and narrow 

geometry. Doering and others (1995) estimated the 

residence time (during the summer) of the Bass Harbor 

estuary, which is hydrologically similar to Northeast 

Creek, to be 3 days. The degree to which spring sequestration can occur is limited by the spring residence 

time, which is shorter than the summer residence time 

because flow rates are greater in the spring. Therefore, 

there may be insufficient time for remineralization of 

spring-runoff nitrogen to be a factor during the growing 

season. 

Atmospheric Loading 

Atmospheric loading to Northeast Creek was 

estimated for the direct deposition onto the water 

surface of the creek (0.14 km2). Dissolved inorganic 

nitrogen loads were estimated from weekly concentration and precipitation-volume data from the Acadia 

National Park NADP station (ME98). No corrections 

were made for weeks for which no data were available. 

Concentrations of both ammonia-nitrogen and nitratenitrogen varied greatly. Overall, ammonia accounted 

for approximately 30 percent of the total nitrogen load. 

Monthly wet-deposition loads for April 1999 

through September 2000, along with measured precipitation at the Acadia National Park weather station, are 

shown in figure 11. (Precipitation amounts from the 

weather station are shown because there were periods 

of missing record at the NADP station.) Monthly 

nitrogen deposition ranged from a low of 1 kg 

(May 1999) to a high of almost 10 kg (May 2000). The 

period of record is too short to discern seasonal trends 

in deposition. The relative heights of the load bars and 

the precipitation bars show the variation in the concentration of nitrogen in the precipitation. Months for 

which the bars are of similar height indicate relatively 

high nitrogen concentrations. Months, such as 

September 1999, for which the precipitation bar is 

much higher than the nitrogen bar, reflect the occurrence of storms with low nitrogen concentrations. In 

fact, in September 1999, precipitation was dominated 

by large Atlantic hurricanes, which do not form over 

land areas with large nitrogen sources. 

Total inorganic wet deposition rates for the study 

period averaged 430 kg/km2/yr. This rate is smaller 

than the total nitrogen deposition rate (wet and dry) of 

730 +/- 100 kg/km2

/yr reported by Jordan and Talbot 

(2000), but larger than other estimates, such as that 

reported by Alexander and others (2001), who estimated a deposition rate for nitrate-nitrogen of only 

187 kg/km2

/yr for the Casco Bay watershed in 

southern Maine. Jordan and Talbot (2000) reasoned 

that the discrepancy between their data and data from 

the NADP program may be the result of differences in 

sample-preservation techniques; it also may result from 

the different methods of using the nitrogen-concentration and precipitation volume data in the yearly load 

calculations. In the NADP program, weekly loads are 

not calculated, rather a volume-weighted mean concentration is used to estimate yearly loads, to reduce the 

effects of weeks for which no data are available. Only 

wet-deposition inorganic nitrogen values were used in 

the loading calculation for Northeast Creek. 

A recent study of atmospheric deposition in the 

Gulf of Maine (Jordan and Talbot, 2000) determined 

that organic nitrogen typically accounted for only 3 

percent of the total wet deposition.Adjusting the inorganic nitrogen wet deposition rate at Northeast Creek 

for organic nitrogen and dry deposition would give a 

value of 510 kg/km2

/yr, which is closer to the figure 

reported by Jordan and Talbot (2000). 

The NADP data represent wet deposition only. 

Dry deposition was measured to be 10 to 20 percent of 

the total nitrogen deposition (Jordan and Talbot, 2000). 

Average yearly dry deposition of NO3-N and HNO3-N 

at Howland, Maine, for the period June 1987 through 

November 1997 was 160 kg/km2

/yr (National Oceanic 

and Atmospheric Administration, 2001). 

Ground-Water Loading 

Deep ground water is not considered a significant source of nutrients to Northeast Creek (see section 

on Ground-Water Inflows), as available evidence indicates that little ground water is discharged to the Fresh 

Meadow/Northeast Creek system. The ultimate fate of 

ground water in the bedrock aquifer beneath the Northeast Creek drainage basin was not determined. 

26 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Figure 11. Monthly precipitation and wet deposition of atmospheric nitrogen on Northeast Creek, 

March 1999 to September 2000. 

Another potential source of nutrients to Northeast Creek is shallow ground water in the soils of the 

wetland, which discharges into the creek at the stream 

banks. Determining the flow of water from the wetland 

soils and nutrient concentrations in this water was 

beyond the scope of the present study. In general, 

however, the process of denitrification within the 

wetland soils largely controls the concentration of 

nitrogen in water flowing from the wetland soils to the 

creek. Results of one recent study on the role of denitrification in mediating the inflow of nitrogencontaining ground water to a coastal wetland on Cape 

Cod (Nowicki and others, 1997) indicates that denitrification rates were highest in soils with a high organic 

content and lowest in sandy soils. Denitrification was 

not determined to directly mediate nitrogen loading 

from ground water on Cape Cod because, unlike 

ground water in the Northeast Creek area, most ground 

water there enters the wetland through sandy soils, 

where denitrification rates are low and ground-water 

velocities are high. Overall, denitrification losses were 

found to equal approximately 25 to 40 percent of the 

nitrate-nitrogen inputs from ground water. In 

Narragansett Bay, denitrification reduced about 50 

percent of the inorganic nitrogen load from anthropogenic sources (Seitzinger and others, 1984). The 

processes of mineralization of organic nitrogen to inorganic nitrogen and nitrification within the organic soils 

of the wetland complicates the potential for denitrification to reduce nitrogen inputs from shallow ground 

water. 

Tidal Loading 

Although tidal inputs to Northeast Creek were 

not directly measured in this study, Doering and others 

(1995) measured tidal volumes and nutrient concentrations at Bass Harbor Marsh, another estuarine 

creek/wetland on Mt. Desert Island, and estimated that 

tidal inputs were roughly similar to freshwater inputs. 

The Bass Harbor estuary is similar hydrologically to 

Northeast Creek, and both receive tidal inflow that is 

highly restricted by a berm slightly below the high-tide 

level. Tidal ranges in both estuaries are about 10 to 20 

cm. Doering and others (1995) estimated that 52 

percent of the dissolved inorganic nitrogen load to Bass 

Harbor estuary was from surface water and 48 percent 

was from tidal inputs. It is anticipated that tidal inputs 

will be found to be an important component of the total 

nutrient budget of Northeast Creek as well. 

External Nitrogen Loading To Northeast Creek 27 
Total External Nitrogen Loads 

A seasonal summary of the measured external 

nitrogen loads to Northeast Creek is shown in figure 

12. Estimated surface-water loads show a pronounced 

seasonality, which corresponds primarily to the seasonality of surface-water streamflow. Surface-water loads 

are on average at least two orders of magnitude greater 

than atmospheric loads. Fall, winter, and spring 

surface-water loads are an order of magnitude greater 

than summer loads. Nitrate plus ammonia loads are 

much smaller than the total nitrogen loads, which is 

typical for surface-water-dominated systems. 

Of the individual streams, Stony Brook is 

responsible for 46 percent of the total nitrogen load 

during the study period, and for 59 percent of the 

nitrate-nitrogen load (table 9). The ratio of nitratenitrogen to other nitrogen sources is higher in Stony 

Brook than in the other streams; this finding probably 

is related to the greater amount of old development in 

this basin than in the other basins. 

Atmospheric loads of nitrogen (totaling 85 kg) 

represent only 1 percent of the total external nitrogen 

load for the study period, and less than 10 percent of the 

inorganic nitrogen load. Seasonally, atmospheric loads 

range from 3 to 25 kg of nitrogen and account for 1 to 

23 percent of the total external nitrogen load to Northeast Creek. 

Tidal loads, which were not measured in this 

study, are not shown in figure 12. Because tidal flows 

vary less with precipitation and runoff than do freshwater streams, tidal loads are expected to remain more 

constant during the year. During periods of maximum 

runoff, tidal loads are prevented from entering the 

creek because the water level during a large runoff 

event is higher than the high-tide level (unpublished 

data available at the U.S. Geological Survey office in 

Augusta, Maine). Therefore, tidal nitrogen inputs 

would be reduced during the months when surfacewater inflows were highest, resulting in a seasonal load 

pattern that is the opposite of the surface-water load 

pattern. If the ratio of tidal load to surface-water load 

in Northeast Creek is similar to that observed in the 

Bass Harbor estuary (Doering and others, 1995), then 

tidal loads may dominate nitrogen input to the creek 

during the summer. 

SUMMARY AND CONCLUSIONS 

A calculation of the freshwater inflows to the 

Northeast Creek/Fresh Meadow system shows that 

surface-water flows are the dominant source of freshwater to the system. Freshwater inputs are highly 

seasonal, with relatively little input during the growing 

season (May through September). Evapotranspiration 

from the wetland surface ranged from a low of less than 

2 cm/mo in the winter to highs of 14 cm/mo in July 

1999 and 10 cm/mo in August 2000. Precipitation 

inputs were highly variable. Spring and summer 1999 

were dry—precipitation was approximately half of the 

19-year average recorded at the Acadia National Park 

headquarters monitoring station. Fall, winter, and 

spring of 1999–2000 were normal to wet. Precipitation 

patterns were near-normal in summer 2000, whereas 

September 2000 was very dry. Ground-water inputs 

from the deep bedrock aquifer below the system are 

believed to be negligible because of the presence of a 

marine clay layer under the peat sediments of the 

wetland and Northeast Creek. Shallow ground-water 

inputs to the system were unquantified, but summer 

estimates based on base flow in nearby streams indicate 

that shallow ground-water inputs during the summer 

months are an order of magnitude smaller than other 

inputs. Surface-water outflows plus storage were 

calculated as the residual of the above terms in the 

water budget. Changes in storage can account for 

approximately 5 to 10 percent of the residual during 

months of flooding and floodwater recession, and 60 to 

100 percent of the residual during summertime drawdown from evapotranspiration. Otherwise, net surfacewater outflows generally followed the surface-water 

inflows in magnitude. Outflows were greater than 

inflows during the fall, winter, and spring months, but 

were usually less than inflows during the summer 

months because of evapotranspiration. 

External nitrogen loads also were estimated for 

Northeast Creek. Total nitrogen and nitrate-nitrogen 

loads were calculated for each of the tributaries 

entering Northeast Creek. Inorganic nitrogen loads 

from precipitation were calculated using data from the 

National Atmospheric Deposition Program site at the 

Acadia National Park headquarters. Because of the 

relation between streamflow and load, the surfacewater nitrogen loads to the creek are highly seasonal; 

nitrogen inputs were approximately an order of magnitude lower in the summer than in the other seasons. 

28 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Figure 12. Seasonal nitrogen loads to Northeast Creek from all hydrologic sources. 

Summary and Conclusions 29 
-- -- -- -- -- -- -- -- --

Table 9. Seasonal loading ratios for surface-water and atmospheric sources to Northeast Creek [kg, kilogram; N, nitrogen; --, no data] 

December 

Entire study period 

April-May June- September- 1999- March-May June- September

November (April 1999-

September 2000) 1999 August 1999 1999 February 2000 

August 2000 2000 

2000 

Source 

Total N flux Nitrate-N flux Percent of Percent of Percent of Percent of Percent of Percent of Percent of total total total total total total total 

Total N Percent Nitrate-N Percent Total N Nitrate- Total N Nitrate- Total N Nitrate- Total N Nitrate- Total N Nitrate- Total N Nitrate- Total N Nitrate- (kg) of total (kg) of total N N N N N N N 

Surface-water loads1 Old Mill 1,400 23 140 18 21 18 20 6 16 20 26 16 28 19 27 18 45 11 

Brook 

Stony Brook 2,700 46 460 59 52 60 58 44 53 59 44 54 40 63 49 60 38 39 Aunt Betsey’s 310 5 26 3 4 3 3 23 5 3 5 3 6 3 4 4 2 15 

Brook 

French Hill 490 8 39 5 8 5 5 5 9 4 8 11 8 1 6 4 2 13 

Brook 

Total ungaged 990 17 110 15 16 14 15 21 17 14 17 17 17 13 15 14 13 22 

strea

ms 

Total surface- 5,900 100 780 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 

water loads 

Atmospheric load2 

85 1 1 13 1 1 1 4 23 

1“Percent of total” values represent percentages of surface-water loads. 2“Percent of total” values represent percentages of total load, including atmospheric load. 

30 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
Ammonia loads were not calculated because of the 

large number of samples in which ammonia levels were 

below the 0.05-mg/L detection limit. The surface-water 

nitrogen loads were estimated on the basis of data from 

18 monthly samples collected from the four perennial 

tributaries and on estimated daily streamflows. 

Over the study period, total nitrogen loads to 

Northeast Creek from the tributary basins ranged from 

310 kg from Aunt Betsey’s Brook to 2,700 kg from 

Stony Brook. Stony Brook also contributed 59 percent 

of the nitrate-nitrogen load to Northeast Creek 

(460 kg), whereas Aunt Betsey’s Brook contributed 

only 3 percent (26 kg). Total nitrogen yields ranged 

from 130 kg/km2

/yr in Aunt Betsey’s Brook to 

270 kg/km2/yr in Stony Brook. Nitrate-nitrogen yields 

ranged from 13 kg/km2

/yr in Aunt Betsey’s Brook to 

44 kg/km2/yr in Stony Brook. Overall, these yields are 

lower than yields to eutrophic estuaries elsewhere on 

the East Coast. Differences in the yields of nitratenitrogen and total nitrogen may result from differences 

in the numbers, ages, and proximity of household 

septic systems to surface waters; amount and degree of 

agricultural activity in each basin; and natural factors 

such as burn history and geologic materials. 

Atmospheric loading to the creek surface 

accounted for a very small portion of the total load of 

nitrogen to Northeast Creek. Seasonal atmospheric 

loads ranged from 3 to 25 kg, which represent 1 percent 

(in most seasons of the study period) to 23 percent (in 

September 2000) of the external nitrogen load entering 

the creek. 

Several factors that relate to water and nitrogen 

inputs to this system remain unstudied. The volume of 

shallow ground-water inflow to the Northeast 

Creek/Fresh Meadow system was not quantified during 

this study. Tidal flows and nitrogen concentrations in 

incoming tidal waters would be useful in determining 

the relative importance of all nitrogen sources to Northeast Creek. Water entering the creek from within the 

Fresh Meadow wetland is another unquantified potential source of nitrogen. Information on denitrification 

rates in the wetland soils, nitrogen concentrations in the 

water in these soils, and ground-water levels in the 

wetland is needed to improve the estimates of the 

magnitude of nitrogen entering the creek. 

REFERENCES CITED 

Alexander, R.B., Smith, R.A., Schwarz, G.E., Preston, S.D., 

Brakebill, J.W., Srinivasan, R., and Pacheco, P.A., 

2001, Atmospheric nitrogen flux from watersheds of 

major estuaries of the United States—An application of 

the SPARROW watershed model, in Valigura, R.A., 

Alexander, R.B., Castro, M.S., Meyers, T.P., Paerl, 

H.W., Stacey, P.E., and Turner, R.E., eds., Coastal and 

Estuarine Studies: American Geophysical Union, 

Washington, D.C. p. 119–170. 

Bloom, A.L., 1960, Late Pleistocene changes of sealevel in 

southwestern Maine: Maine Geological Survey, 

Department of Economic Development Report, 140 p. 

Carter, R.W., and Davidian, J., 1968, General procedure for 

gaging streams: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 3, chap. A6, 

13 p. 

Doering, P.H., Beatty, L.L., Keller, A.A., Oviatt, C.A., and 

Roman, C.T., 1995, Water quality and habitat evaluation of Bass Harbor Marsh, Acadia National Park, 

Maine: National Park Service Technical Report 

NPS/NESORNR/NRTR/95-31, 148 p., 4 app. 

Fennessey, N.M., and Vogel, R.M., 1996, Regional models 

of potential evaporation and reference evapotranspiration for the northeast USA: Journal of Hydrology 

(Amsterdam), v. 184, no. 3-4, p. 337–354. 

Gilman, R.A., Chapman, C.A., Lowell, T.V., and Borns, 

H.W., Jr., 1988, The geology of Mount Desert Island, 

a visitor’s guide to the geology of Acadia National 

Park: Maine Department of Conservation, Geological 

Survey Bulletin 38, 50 p., 2 pl. 

Gilroy, E.J., Hirsch, R.M., and Cohn, T.A., 1990, Mean 

square error of regression-based constituent transport 

estimates: Water Resources Research, v. 26, no. 9, 

p. 2069–2077. 

Hansen, B.P., 1980, Ground-water availability in Acadia 

National Park and vicinity, Hancock and Knox Counties, Maine, with a map of surficial geology by H.W. 

Borns and G.W. Smith: U.S. Geological Survey OpenFile Report 80-1050, 8 p., 1 pl. 

Harlin, M.M., 1995, Changes in major plant groups following nutrient enrichment, in McComb, A.J., ed., 1995, 

Eutrophic shallow estuaries and lagoons: Boca Raton, 

Florida, CRC Press, p. 173–187. 

Harlin, M.M., and Thorne-Miller, B., 1981, Nutrient enrichment of seagrass beds in a Rhode Island coastal lagoon: 

Marine Biology, v. 65, p. 221–229. 

Helsel, D.R., and Hirsch, R.M., 1992, Statistical methods in 

water resources: Studies in Environmental Science 49, 

Amsterdam, Elsevier Science Publishers, 522 p. 

Hirsch, R.M., 1982, A comparison of four streamflow record 

extension techniques: Water Resources Research, v. 18, 

no. 4., p. 1081–1088. 

References Cited 31 
Hodgkins, G.A., 2001, Calculation of streamflow and total 

phosphorus loads for selected tributaries to Sebago 

Lake, Maine: U.S. Geological Survey Water-Resources 

Investigations Report 01-4003, 15 p. 

Jordan, C.E., and Talbot, R.W., 2000, Direct atmospheric 

deposition of water-soluble nitrogen to the Gulf of 

Maine: Global Biogeochemical Cycles, v. 14, no. 4, 

p. 1315–1329. 

Kinney, E. H., and Roman, C.T., 1998, Response of primary 

producers to nutrient enrichment in a shallow estuary: 

Marine Ecology Progress Series, v. 163, p. 89–98. 

McClelland, J.W., and Valiela, I., 1998, Linking nitrogen in 

estuarine producers to land-derived sources: Limnological Oceanography, v. 43, no. 4, p. 577–585. 

Meyer, J.L, and Likens, G.E., 1979, Transport and transformation of phosphorus in a forest stream ecosystem: 

Ecology, v. 60, p. 1255–1269. 

Morrison, M., 1989, Quality-assurance plan for the longterm monitoring program: Corvalis, Oregon, U.S. Environmental Protection Agency Laboratory, 77 p. 

National Atmospheric Deposition Program, 1999, Inside 

rain—A look at the National Atmospheric Deposition 

Program: NADP Brochure 1999-01b (revised), 25 p. 

National Oceanic and Atmospheric Administration, 2001, 

National Oceanic and Atmospheric Administration 

(NOAA)/Air Resources Laboratory (ARL) Atmospheric Integrated Research Monitoring Network (AIRMoN) web site: http://www.arl.noaa.gov/research/ 

projects/airmon_dry.html, accessed 2/9/01. 

Nowicki, B.L., Requintina, E., and Van Keuren, D., 1997, 

The role of sediment denitrification in reducing groundwater-derived nitrate inputs to Nauset Marsh Estuary, 

Cape Cod, Massachusetts: U.S. National Park Service 

Technical Report NPS/NESO-RNR/NRTR/97-10, 50 p. 

Rantz, S.E., and others, 1982, Measurement and computation of streamflow: U.S. Geological Survey Water-Supply Paper 2175, 2 v., 631 p. 

Robertson, D.M., and Roerish, E.D., 1999, Influences of various water quality sampling strategies on load estimates 

for small streams: Water Resources Research, v. 35, 

no. 12, p. 3747–3759. 

Searcy, J.K., 1959, Flow-duration curves, Manual of hydrology–part 2, Low-flow techniques: U.S. Geological Survey Water-Supply Paper 1542-A, 33 p. 

Seitzinger, S.P., Nixon, S.W., and Pilson, M.E.Q., 1984, 

Denitrification and nitrous oxide production in a coastal 

marine ecosystem: Limnological Oceanography, v. 29, 

no. 1, p. 73–83. 

Short, F.T., and Burdick, D.M., 1996, Quantifying eelgrass 

habitat losses in relation to housing development and 

nitrogen loading in Waquoit Bay, Massachusetts: Estuaries, v. 19, no. 3, p. 730–739. 

Stewart, G.J., Nielsen, J.P., Caldwell, J.M., and Cloutier, 

A.R., 2001, Water resources data for Maine, water year 

2000: U. S. Geological Survey Water-Data Report ME00-1, 233 p. 

Stoddard, J.L., 1994, Long-term changes in watershed retention of nitrogen—Its causes and aquatic consequences, 

in Environmental Chemistry of Lakes and Reservoirs: 

American Chemical Society National Meeting, Atlanta, 

Ga., April 1991, Monograph, p. 223–284. 

Thompson, W.B., and Borns, H.W., 1985, Surficial geologic 

map of Maine: Maine Department of Conservation, 

Geological Survey Map, scale 1:500,000, 1 sheet. 

Turnbull, B.W., and Weiss, L., 1978, A likelihood ratio statistic for testing goodness of fit with randomly censored 

data: Biometrics, v. 34, p. 367–375. 

U.S. Bureau of the Census, 1992, 1990 census of population 

and housing—Population and housing unit counts, 

Maine: U.S. Department of Commerce, Bureau of the 

Census, 1992. 

Valiela, I., Foreman, K., LaMontagne, M., Hersch, D., Costa, 

J., Peckol, P., DeMeo-Andreson, B., D’Avanzo, C., 

Babione, M., Sham, C., Brawley, J., and Lajtha, K., 

1992, Couplings of watersheds and coastal waters— 

Sources and consequences of nutrient enrichment in 

Waquoit Bay, Massachusetts: Estuaries, v. 15, no. 4, 

p. 443–457. 

Valiela, I., Teal, J. M., Volkmann, S., Shafer, D., and Carpenter, E.J., 1978, Nutrient and particulate fluxes in a salt 

marsh ecosystem—Tidal exchanges and inputs by precipitation and groundwater: Limnological Oceanography, v. 23, no. 4, p. 798–812. 

32 Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine 
District Chief

Maine District

U.S. Geological Survey

Water Resources Division

26 Ganneston Drive

Augusta, Maine 04330

U.S. Geological Survey WRIR Report 02-4000 

Nielsen, M.G., Water Budget for and Nitrogen Loads to Northeast Creek, Bar Harbor, Maine — 

Printed on recycled paper