Northeast Region—Urban Landscapes Capability Team

Urban Development and Stream Ecosystem Health—Science 

Capabilities of the U.S. Geological Survey

Urban development creates multiple stressors that can degrade stream ecosystems by changing stream hydrology, water quality, 

and physical habitat. Contaminants, habitat destruction, and increasing streamflow variability resulting from urban development 

have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic biota. Understanding 

how algal, invertebrate, and fish communities respond to these physical and chemical stressors can provide important clues as to 

how streams should be managed to protect stream ecosystems as a watershed becomes increasingly urbanized. The U.S. Geological 

Survey (USGS) continues to lead monitoring efforts and scientific studies on the effects of urban development on stream ecosystems in 

metropolitan areas across the United States.

Expertise and Resources

The USGS scientists of the Northeast Region Urban Landscapes 

Capability Team share expertise and resources to provide and interpret 

data on a wide range of urban-related issues at local, regional, and 

national levels. Data collected from traditional water and bed-sediment 

samples are complemented with ecological toxicity and bioassay 

analyses to assess the exposure and vulnerability of organisms living in 

stream water and bed sediments. The ecological condition of streams 

and lakes are assessed by surveying fish, invertebrate, and algal communities and by analyzing biological tissues for contaminants.

Streamflow Variability and Loss of Sensitive Species

Natural fluctuations of flows are critical to stream health because 

they build and maintain physical habitats, influence physical and chemical characteristics of water, and provide important life-stage cues for 

aquatic organisms. Urban development typically modifies streams by 

altering the magnitude, duration, frequency, and timing of streamflow. 

As the percentage of impervious surfaces and levels of stormwatermanagement controls increase with urban development, the amount 

of runoff entering streams frequently results in higher flows that can 

alter stream habitat from channel erosion. Additionally, rapid runoff 

reduces soil infiltration and aquifer recharge, which often results in 

lower sustained streamflows during summer. These changes generally 

result in a shift in the species composition of the biological communities, specifically with losses of fish species diversity and sensitive 

invertebrate species. As a result, the biological community shifts to a 

higher percentage of species more tolerant to physical and chemical 

stressors. Understanding how stream ecosystems change with increasing urban development can assist in the development of protective 

and rehabilitative management actions. Results from USGS studies 

(http://water.usgs.gov/nawqa/urban/html/publications.html) document 

the pervasiveness and severity of streamflow modification across the 

Nation and provide water-resources managers with regional-scale 

perspectives on the importance of maintaining natural streamflow to 

preserve biological communities and stream health.

Chemical Stressors and Ecosystem Health

Urban development may increase the inputs to streams of complex 

chemical mixtures typically present in runoff from impervious surfaces 

in industrial and suburban areas. These mixtures may include pesticides, nutrients, chloride, metals, organic wastewater compounds, and 

other chemicals that have deleterious biological effects. These effects 

of toxicity on the biological communities may be defined in terms of 

Photograph of a brown bullhead (Ameiurus nebulosis) with lip tumors 

that was collected from the Presque Isle Bay Area of Concern in Erie, 

Pennsylvania. Bullhead species dwell and feed near bottom sediments; 

therefore, they are often used as an indicator species of environmental health (Blazer and others, 2014). Photograph by Vicki Blazer, 

U.S. Geological Survey.

Hours

0 10 20 30 40 50

0

5

10

15

Rate of decline

Magnitude

Duration

EXPLANATION

Developed

Undeveloped

Streamflow (cubic meters per second)

A common effect of urbanization on stream hydrology is that the 

frequency and magnitude of high flows generally increase and flow 

durations generally decrease as a result of rapid runoff from impervious 

surfaces. Figure from Coles and others (2012).

U.S. Department of the Interior

U.S. Geological Survey

Banner photograph: Boston skyline by Bill Damon,

Creative Commons Attribution 2.0 Generic license.

Fact Sheet 2016–3026

April 2016
limited survival, growth, and reproduction. Minor amounts of some 

compounds commonly present in urban streams may have immediate or long-term effects on ecosystem community structure, diversity, 

and productivity. For example, endocrine disruption (U.S. Geological 

Survey, 2009) and reproductive effects have been documented for fish 

(Blazer and others, 2013) from contaminants of emerging concern such 

as hormones, estrogenic pesticides (U.S. Geological Survey, 2012), and 

wastewater compounds. The bioaccumulation of trace elements, such as 

mercury, has been indicated to have reproductive and behavioral effects 

on fish and their higher level predators. Large increases in stream chloride concentrations in watersheds with increased urban development 

have been observed throughout the Northeastern United States where 

road salt and deicing chemicals are used extensively and may affect the 

survival of sensitive aquatic species.

In urban environments, increased stormwater runoff can introduce 

contaminants to the streams and alter streambed sediment chemistry 

and, thereby, increase the associated toxicity to biological communities. Flushing of urban streams during flood events can then resuspend 

and redistribute these contaminated sediments along the streambed and 

into downstream estuaries. The USGS stream assessment capabilities 

include identifying the presence of specific contaminants in water, sediment, and biological tissue, and evaluating ecosystem health by testing 

ecological toxicity.

Ecological toxicity tests provide data on the lethal and sublethal (reproductive, developmental, and behavior) effects of the chemical composition of the bed-sediment samples to which the organisms are exposed. 

Photograph by Jacob K. Stanley, U.S. Army Corps of Engineers.

Examples of USGS Urban Ecology Studies

USGS National Water Census

Tributaries in the Delaware River Basin are currently [2016] 

being studied to define relations that exist among major components of streamflow (magnitude, durations, frequency, timing, and 

rate of change) and the response of aquatic biological communities. 

This information will assist managers in making decisions about 

meeting human water needs while maintaining a healthy stream. 

http://water.usgs.gov/watercensus/delaware.html

Northeast Region Stream Quality Assessment

The goal of the Northeast Stream Quality Assessment study is to 

assess the quality of streams in the region by characterizing multiple 

water-quality factors that are stressors to aquatic life and evaluating 

the relation among these stressors and biological communities. The 

Northeast Stream Quality Assessment will focus on the effects of 

urbanization and agriculture on stream quality in New England, New 

York, and the northernmost parts of New Jersey and Pennsylvania. 

http://txpub.usgs.gov/RSQA/

USGS Environmental Health Program 

Contaminants of emerging concern can have natural or synthetic 

sources that are present in the environment but are not commonly 

monitored. The USGS has ongoing environmental health research 

in the Northeast Region and nationally on these contaminants 

because these chemical compounds have the potential to cause 

adverse ecological or human health effects, or both. The primary 

goals of the research program are to develop analytical methods 

to detect these contaminants at low concentrations and to provide 

information on the frequency of detection, sources, transport and 

fate, and ecological effects of a variety of emerging contaminants. 

http://toxics.usgs.gov/regional/emc/index.html

USGS Regional Studies on the Effects of Urbanization on Stream 

Ecosystems

As part of the USGS National Water Quality Assessment, researchers studied the relation between varying levels of urban intensity and 

stream water quality, as measured by physical, chemical, and biological 

factors in 11 metropolitan areas. For these studies, stream water quality was considered a composite of physical, chemical, and biological 

characteristics influenced by natural factors and by human activities. 

Biological communities reflect the integration of these influences. 

http://water.usgs.gov/nawqa/urban/index.html

Partnering Opportunities

The USGS is a leader in monitoring the effects of urban development and land-use change on stream ecosystems. Ecosystem studies 

led by the USGS use standardized protocols and analytical procedures 

to integrate data from multiple biological communities so that assessments of stream health and its relation to urbanization can be compared 

nationally and locally. Access to USGS expertise is possible through 

numerous partnering opportunities. State and local agencies may partner with the USGS and access matching funds through the Cooperative Water Program (http://water.usgs.gov/coop/). Federal agencies, 

educational institutions, nonprofit organizations, and other entities may 

partner with the USGS through a variety of programs. 

References Cited

Blazer, V.S., Mazik, P.M., Iwanowicz, L.R., Braham, R.P., Hahn, C.M., Walsh 

H.L., and Sperry, A.J., 2014, Assessment of the fish tumor beneficial use 

impairment in brown bullhead (Ameiurus nebulosus) at selected Great Lakes 

areas of concern: U.S. Geological Survey Open-File Report 2014–1105, 

17 p., accessed April 12, 2016, at http://dx.doi.org/10.3133/ofr20141105.

Blazer, V.S., Pinkney, A.E., Jenkins, J.A., Iwanowicz, L.R., Minkkinen, Steven, 

Draugelis-Dale, R.O., and Uphoff, J.H., 2013, Reproductive health of yellow 

perch Perca flavescens in selected tributaries of the Chesapeake Bay: Science of the Total Environment, v. 447, p. 198–209, accessed April 12, 2016, 

at http://www.sciencedirect.com/science/article/pii/S0048969712016452.

Coles, J.F., McMahon, Gerard, Bell, A.H., Brown, L.R., Fitzpatrick, F.A., 

Scudder Eikenberry, B.C., Woodside, M.D., Cuffney, T.F., Bryant, W.L., 

Cappiella, Karen, Fraley-McNeal, Lisa, and Stack, W.P., 2012, Effects of 

urban development on stream ecosystems in nine metropolitan study areas 

across the United States: U.S. Geological Survey Circular 1373, 138 p., 

accessed April 12, 2016, at http://pubs.usgs.gov/circ/1373/.

U.S. Geological Survey, 2009, Tackling fish endocrine disruption: U.S. Geological Survey Environmental Health Web page, accessed April 12, 2016, at 

http://toxics.usgs.gov/highlights/fish_endocrine_disruption.html.

U.S. Geological Survey, 2012, Pyrethroid insecticide contamination of streams 

increases with urbanization: U.S. Geological Survey Environmental Health 

Web page, accessed April 12, 2016, at http://toxics.usgs.gov/highlights/pyrethroids_in_streams.html.

By Pamela A. Reilly, Zoltan Szabo, and James F. Coles

For more information about these USGS projects and about 

partnering opportunities, contact:

USGS Northeast Region Urban Landscapes Capability Team

Email: GS-NE_ULCT@usgs.gov

or contact your local USGS office

https://www.usgs.gov/contact_us

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20163026