New Jersey Department of Environmental Protection Division of Coastal and Land Use Planning
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Altered Hydrology New Jersey’s waterways have been altered through historical development trends, run-off, pollution, dams, and other natural events. Decades of observation of the effects of human alterations of natural flow regimes have established that altering the hydrologic regimes in rivers can be ecologically deleterious. Many argue that stream flow quantity and times are critical factors that affect the ecological integrity of river systems. Additionally, many studies have documented ecological responses to alterations of the natural flow regime; examples include fish life-cycle disruption, encroachment of vegetation, loss of sensitive aquatic-invertebrate species, and loss of fish access to backwaters and wetlands.3 Alteration of natural hydrologic regimes is a consistent and pervasive effect of urbanization within stream ecosystems, as discharge patterns—the amount and timing of water flow through streams—change with urban development. Key aspects of urbanization affecting hydrology may include: ↓ infiltration and ↑ surface runoff of precipitation associated with impervious (and effectively impervious) surfaces ↑ speed and efficiency of runoff delivery to streams, via stormwater drainage infrastructure ↓ evapotranspiration due to vegetation removal ↑ direct water discharges, via wastewater and industrial effluents ↑ infiltration due to irrigation and leakage from water supply and wastewater infrastructure ↑ water withdrawals and interbasin transfers Commonly reported effects of urbanization on stream flow regimes include (but are not limited to): STORMFLOW↑ high flow frequency ↑ high flow magnitude ↑ flashiness or rapidity of flow changes ↓ high flow duration ↓ lag time BASEFLOW↓ low flow magnitude ↑ low flow magnitude ↑ low flow duration These hydrologic changes can reduce habitat quality in urban streams, and adversely affect stream biota. For example, high flows can scour organisms and substrate from streambeds, while low flows can reduce habitat area and volume. 1 Hasse, John E. and Richard G. Lanthrop. Changing Landscapes in the Garden State: Executive Summary. Glassboro: Rowan University and Rutgers, The State University of New Jersey, 2010. Page 5. 2 NJDEP Office of Science. Environmental Trends Report: Endangered Plants. http://www.state.nj.us/dep/dsr/trends: New Jersey Department of Environmental Protection, 2013. Page 4. 3 Kennen, J.G., Riskin, M.L., Riley, P.A., and Colarullo, S.J. "Method to Support Total Maximum Daily Load Development using Hydrologic Alteration as a Surrogate to address Aquatic Life Impairment in New Jersey Streams." 2013. http://pubs.usgs.gov/sir/2013/5089/. Page 9. Directory: dep -> landuse -> download dep -> Black Panther Party Lesson Plan Aligned to Grade 11 gles Targeted Length: Two 90-Minute class periods created by Teresa Frizell dep -> #1 a lifesafer of virginia inc dep -> State of florida department of environmental protection dep -> Office of the collector: jagatsinghpur (st & sc development Section) dep -> Town of Nags Head Annual Report dep -> The Intimate Stranger dep -> General information dep -> Data Analysis (Math 206) Exam 2 Name Spring 2002 Hartlaub dep -> Engineering Library Reference Manual download -> State of New Jersey Approved Wetlands Mitigation Banks as of 3/24/17 Download 1.99 Mb. Share with your friends:
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