AWWA SRC58322

The New York City Water Supply System provides drinking water for 9 millionconsumers in the city and surrounding areas. Most of this water comes from near-pristinesources in the Catskill and Delaware Systems, but up to 30% is supplied by the CrotonSystem. The 380 square mile Croton Watershed, which first supplied water to New YorkCity in 1842, adjoins the City and consists primarily of residential and natural areas. TheNew York City Department of Environmental Protection (NYCDEP) is researchingcurrent and future risks to Croton water quality and looking for effective and efficientmanagement strategies to ensure source water protection as growth occurs andregulations become increasingly stringent.A team of engineering consultants worked with NYCDEP to develop a GIS-based riskassessment methodology that addresses nutrient, solids, pathogen, and toxics impairmentsfrom land-based, septic, and point sources. The methodology combines numerical scoresreflecting risk, proximity, and severity for each source category to generate total scores.The assessment results are used to create Basin Reports which summarize current risklevels and possible future trends, while a decision support tool implementing themethodology will be used to evaluate alternative management scenarios. With this tool,NYCDEP will be able to prioritize its watershed monitoring, modeling, protection andrestoration efforts as well as provide local stakeholders with technical information fortheir own watershed programs. The types of watershed strategies likely to be employedare land acquisition, stormwater BMPs, septics management, and smart development.This paper discusses the importance of the Croton Watershed to New YorkCity's water supply and provides an overview of the watershed assessment methodology.A sample Basin Report is presented and explained, and a short demonstration of theGIS-based decision support tool is included. The paper concludes with asummary of expected future directions in the management of the Croton Watershed. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/19/2003

Number of Pages:

33

File Size:

1 file , 2.3 MB