New York Watershed -- Paper #1

New York City’s water supply system is one of the most extensive municipal water systems in the world. This complex system relies on a combination of tunnels, aqueducts, and reservoirs. Each day New York City delivers water to over 8 million city residents and another 1 million consumers who live in Westchester, Putnam, Ulster, and Orange counties north of the city. New York’s water system is a well-protected wilderness watershed where 95% of the total water supply is supplied by gravity. The other 5% needs to be pumped to maintain pressure. A network of 19 reservoirs and three controlled lakes in a 1,972 square mile watershed supplies the source of New York City’s drinking water. The city has sought to restrict development throughout its watershed.

The New York City Department of Environmental Protection has a workforce that includes three bureaus in charge of the upstate water supply system, they city’s water and sewer operations and waste water treatment.  The water supply unit manages, operates and protects New York City’s upstate water supply system to ensure the delivery of a sufficient quantity of high quality drinking water. The water and sewer operations regulate the Staten Island Bluebelt. It is an ecological sound that is a cost effective natural alternative to storm sewers. This project preserves streams, ponds, and other wetland areas, allowing them to perform their natural functions of conveying, storing, and filtering storm water. Lastly, the wastewater treatment operates 14 water pollution control plants treating an average of 1.5 billion gallons of wastewater a day, 89 wastewater pump stations, 8 dewatering facilities, 490 sewer regulators, and 6,000 miles of intercepting sewers.

A watershed is a geographic area whose rainfall, snowmelt, streams and rivers all flows or drains into a common body of water, such as a reservoir, lake, or bay. Ultimately most watersheds in the U.S. drain into the Atlantic or Pacific Oceans or the Gulf of Mexico. Regardless if your drinking water comes from a surface supply – reservoirs, rivers or lakes – or underground sources called aquifers, everyone lives in a watershed. As water travels over land or through the ground, it picks up naturally occurring minerals as well as contaminants from animals and human activities. Watershed protection efforts generally focus on human and animal contaminants as well as the way pollutants are transported across the landscape. The essence of watershed management – which is the purpose of organizing and guiding land and natural resources use to reflect the competing needs and priorities of all stakeholders, is to prevent contaminants from reaching water resources. With careful planning and communications, water quality can be protected while still serving multiple priorities.

In the New York City water supply watersheds, key stakeholders include the 9 million urban consumers of the water supply, nearly a quarter million residents of the older and more suburbanized Croton Watershed, tens of thousands of residents of the rural Catskill/Delaware Watershed, and the diverse flora and fauna of the entire watershed ecosystem. This complex web of multiple stakeholders means that watershed protection requires a delicate balance between urban/rural and upstate/downstate interests. The New York City water system has a storage capacity of 550 billion gallons and provides over 1.2 billion gallons per day of drinking water to more than 8 million city residents and another 1 million users in four upstate counties bordering on the water supply system.

The New Croton aqueduct, completed in 1890 brings water from the New Croton Reservoir in Westchester and Putnam counties. The Catskill aqueduct, completed in 1916, is significantly larger than the Croton and brings water from two reservoirs in the eastern Catskill Mountains. The Delaware aqueduct, completed in 1945, taps tributaries of the Delaware River in the western Catskill Mountains and provides around half of the city’s water supply. The latter two aqueducts provide 90% of the drinking water to the city. Water from both aqueducts is stored first in the large Kensico reservoir and subsequently in the much smaller Hillview reservoir closer to the city. From the Hillview reservoir, water flows by gravity through three tunnels under the city, where the water rises again to the surface under natural pressure through a number of shafts. The New York City Water Tunnel No. 1 runs from the Hillview reservoir under the central Bronx, Harlem River, West Side, Midtown and Lower East Side and under the East River to Brooklyn where it connects to Tunnel No. 2. Tunnel No. 2 runs from the Hillview reservoir under central Bronx, East River, and western Queens to Brooklyn where it connects to Tunnel No. 1 and the Richmond Tunnel to Staten Island. And Tunnel No. 3 is under construction. It is the largest capital construction project in New York City.

References

1. "History of New York City's Water Supply System". New York City Department of Environmental Protection. http://nyc.gov/html/dep/html/drinking_water/history.shtml. Retrieved 2009-12-08.
2. "Bureaus and Offices". New York City Department of Environmental Protection. http://www.nyc.gov/html/dep/html/about_dep/bureaus.shtml#WaterSupply. Retrieved 2010-07-10.
3. "New York City's Water Supply System Map". New York City Department of Environmental Protection. http://www.nyc.gov/html/dep/html/drinking_water/wsmaps_wide.shtml. Retrieved 2009-09-03.
4. "World's Longest Water Tunnel". Popular Science: 35. December 1932. http://books.google.com/books?id=iigDAAAAMBAJ&pg=PA35. Retrieved 2011-09-27.
5. http://www.nyc.gov/html/dep/html/wastewater/wwsystem-history.shtml