NYC Water Supply System 8: Nature of New York’s NYC’s water supply Water Resources system is a watershed- based, gravity flow model (pumping = <5%) that NYC Water Supply moves water 125 miles from the Catskills to New York City via the Prof. Anthony Grande Croton Watershed. Geography Dept. Hunter College-CUNY It also provides water for communities along the path Spring 2018 of its aqueducts. Lecture design, content and Link to the parts of the NYC reservoir system: presentation ©AFG 0218. Annual Drinking Water Quality Report with map: Individual images and illustrations 1 http://www.nyc.gov/html/dep/html/watershed_ 2 may be subject to prior copyright. http://www.nyc.gov/html/dep/pdf/wsstate17.pdf protection/reservoirs.shtml NYC Water Distribution System NYC Water Distribution System 1830s: Water shortages in 1907-1927 – CATSKILL Manhattan were common. H SYSTEM was constructed. Catskill NYC relied on natural ponds and U System small reservoirs. D • The ASHOKAN RESERVOIR was 1840s: CROTON SYSTEM was S built in river valleys west of Kingston. H O • The CATSKILL AQUEDUCT carried U built in Westchester with an D aqueduct bringing the water to N water by gravity to the Kensico S Catskill distribution reservoirs in Manhattan. New Reservoir of the Old Croton System O Aqueduct Croton N • 1850s-1880s: Croton System R • A tunnel crossed the Hudson. I System • The SCHOHARIE RESERVOIR was was expanded northward R (NEW CROTON SYSTEM 1890). V built to supplement water storage I E “just in case”! V E • 1880-90s: Croton System R couldn’t keep up with demand Before the Catskill System R esp. after the City of Brooklyn was Original was finished, it was realized connected to the system. Croton that it could not provide NYC’s 1905: After a Board of Water System increasing demand for water! Supply study, the CATSKILL SYSTEM was funded by NYS. To 3 4 NYC Construction of the Catskill Ashokan Watershed and Reservoir Aqueduct, 1913 Constructed in the Catskills starting in 1907 Ashokan Reservoir Dam under construction N.Y.C. Water behind the Ashokan Dam flooded valleys that contained Water towns, farms, cemeteries and roads, displacing local residents. Supply Today signs around the reservoir System indicate the location of features flooded by the reservoir 1 NYC Water Distribution System NYC Water Supply System http://www.nyc.gov/html/dep/html/watershed_protection/reservoirs.shtml Delaware The NYS Legislature authorized Catskill System NYC to tap the headwaters of System the DELAWARE RIVER on the west side of the Catskills. H U • Starting in the1920s the DELA- D WARE SYSTEM was constructed. S O • THREE RESERVOIRS were built - N RONDOUT, NEVERSINK and Delaware PEPACTON. Aqueduct R TUNNELS were required to move I water across the watershed V E divides to the Rondout. R • The DELAWARE AQUEDUCT carries water across the Hudson to the Croton Watershed. • The CANNONSVILLE RESERVOIR, the last of the system, was put into service in the mid-1960s 7 8 Delaware River Western NYC Water Distribution System Catskills Watershed in NYS • NYC’s water supply is a watershed-based system using gravity flow methodology, with some pumping, to move water 125 mi. from the Catskills to NYC. More than just a New York The Catskill-Delaware System provides 90% of the water. watershed. The Croton System provides 10%. • Headstreams of the Delaware Has 19 reservoirs and 3 controlled lakes. rise in the Catskills. PA Water is moved via gravity through a series of aqueducts • NYC dams the headstreams for NJ to terminal reservoirs (Kenisco) in Westchester County. its water supply. Water goes through a purification process before enter- PA, NJ and DEL have success- ing the tunnels of the distribution system. fully sued NYS to release A series of water tunnels delivers the water to all five greater amounts of water from DEL boroughs via water pressure created by gravity. Less than 5% of the water is pumped on a regular basis to maintain pressure. the NYC reservoirs. 9 10 PROBLEMS facing the NYC NYC Drinking Water Supply System Water Report Water volume problems. Water quality problems. Supply: cities and towns Salt in the water from win- •NYC and NYS monitor along the right-of-way tap ter road salting followed by the city’s water supply. into the system. snowmelt and rain. PA, NJ and DE have sued Seepage from septic A Drinking Water NYS and won to get a tanks, gasoline tanks, etc. Supply and Quality guaranteed flow of water Run off from farms, land- down the Delaware River. fills and other places. Report is issued Dependent on rain and Airborne pollutants. every year. See it at: snow melt. Reservoir Quality of pipes. http://www.nyc.gov/html/dep/pdf/ws levels lower in times of http://www.nyc.gov/html state17.pdf /dep/pdf/wsstate15.pdf drought. (1981 = 33% capacity; Threat from terrorism. 2002 = 41% capacity) Look over the information provided at this site: http://www.nyc.gov/html/dep/html/drinking_water/index.shtml 11 NOTE: Change the number and hit return to view other years. 12 To see 2010’s report, change the 17 to a 10. 2 NEXT GROUNDWATER 13 3.