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A Landscape Analysis of New York City's Water Supply


Principal Investigators: Megan Mehaffey, Tim Wade, Maliha Nash, Curt Edmonds, and Don Ebert

U.S. Environmental Protection Agency, Office of Research and Development, Las Vegas, Nevada 89193-3478.


This study was initiated as a first step to understand human perturbation on landscape and water resources in the Catskill/Delaware watershed from 1970 to present. Changes in landscape pattern, resulting from human use, will influence the hydrology of an area by increasing water flow, temperature, chemical makeup and benthic structure of the local rivers, streams and creeks. Temporal and spatial changes in landscape pattern and water quality can be examined, to provide a basis for better understanding the interactions between local and regional community activities and their watershed.


With the development of the Croton and Catskill/Delaware systems, New York City’s water quality was one of the highest in the nation. However, with increased pressures from both agriculture and urban growth water quality has begun to decline and the potential for contamination has increased. Evidence of decline can be seen in the ever increasing numbers of alerts to boil water over the past five years. Non-point pollution from runoff and wastewater discharge from treatment plants has resulted in increasing microbial pathogen counts and greater nutrient enrichment in the water supply. While the greater problems have occurred in water coming from the Croton watershed, a similar pattern of decline is starting to emerge in the Catskill/Delaware system. Currently the city is trying to halt the decrease in water quality through the development and implementation of a long-range watershed protection program. The plan was signed in 1997 and unites efforts by the local communities, the city and state of New York, environmental groups, and the EPA to preserve the high quality of New York Cities drinking water supply. The plan includes upgrading current sewage treatment plants, implementing new watershed regulations, and land acquisition.

Land acquisition was selected, partly to protect the environment, but also as a means to save the taxpayers of New York state billions of dollars. Installing a filtration system for the cities water supply would cost an estimated 2-8 billion dollars, verses the 250-300 million dollars set aside for purchase of land. The majority of land acquisition will occur in the Catskill/Delaware watershed. The city has set as its goal purchasing 90 to 120 thousand acres of the watershed. Under the agreement the State Department of Environmental conservation issued a permit to acquire land through outright purchase and conservation easement. Priority is being given to purchase of undeveloped land around reservoirs, streams and wetland areas. Secondary land acquisition will focus on the purchase of sensitive lands surrounding streams and rivers. In conjunction with the watershed protection program the city of New York is working with the Watershed Agriculture Council and the United States Department of Agriculture in developing a Conservation Reserve Enhancement Program (CREP) to help protect, restore and manage these sensitive lands. The program pays farmers to remove sensitive lands from production and apply conservation practices in place of crops. A total of 3,000 acres of highly erodible land and 2,000 acres of riparian buffer lands have been targeted for protection under CREP. The expected result of land acquisition and conservation practices is the protection of over 165 stream miles, the preservation of thousands of acres of natural areas, and continued high water quality without the cost of a $6 billion filtration system.


The following objectives are to be examined by this study:


This study has the potential to provide an index of landscape change during three decades (1970-1990) for the Catskill/Delaware watershed. If water quality data is found to be consistent and geographically relevant in nature then landscape indicators for factors influencing water resource conditions will also be developed. The research will help a number of organizations trying to evaluate vulnerability of land and water resources to change over time at the watershed, basin and sub-basin scales, such as the EPA Region 3 and Office of Water. It should also provide information needed to develop land acquisition and management strategies for reducing impacts to water resources. Organizations that will benefit by this research include the New York City Watershed Council, New York Department of Environmental Conservation(NYDEC), New York Department of Environmental Protection(NYDEP) all are helping to implement the New York Water Supply Protection Plan. Other organizations which would benefit are the United States Geographic Survey (USGS), which is has on going monitoring in the watershed and is currently doing a similar study along the Delaware river, the United States Department of Agriculture, which has started a Conservation Reserve Enhancement Program (CREP) targeting sensitive lands along streams and rivers in the Catskill/Delaware watershed, and the United States Forest Service (USFS), which monitors the Catskill Park and Preserve.

You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.



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