Warning: Javascript must be enabled to use all the features on this page!

Page Loading - Please Wait...

* We've detected you're using a mobile device. Find our Next Generation Station Page here.
Click to hideNews Bulletins

Water-Year Summary for Site 01366400

Click to hide Water-Year Summary instructions and information
  • Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
  • For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
  • For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
  • For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
  • Not all sites have reports available for every water year.
Available Parameters
62614 Elevation, lake/res, NGVD29(Ins.)  

Water year 2020: 2020-10-01 to 2021-09-30

Print this page
USGS Water-Year Summary 2020
LOCATION - Lat 41°47'57", long 74°25'48" referenced to North American Datum of 1927, Ulster County, NY, Hydrologic Unit 02020007, at release chamber at Merriman Dam on Rondout Creek, 1.1 mi upstream from Brandy Brook, and 1.3 mi northwest of Lackawack.
DRAINAGE AREA - 95.4 mi².
PERIOD OF RECORD - May 1951 to September 2013 (month-end elevations, contents, and diversions). October 2013 to current year (daily observation elevations).
GAGE - Water-stage recorder. Datum of gage is NGVD of 1929 (levels by Board of Water Supply, City of New York).
COOPERATION - Elevation record and capacity table provided by New York City Department of Environmental Protection.
REMARKS - Reservoir is formed by an earthfill rockfaced dam; storage began May 10, 1951. Initial filling (to crest of spillway) Mar. 28, 1955. Usable capacity 50,048 mil gal between minimum operating level, elevation 720.00 ft, and crest of spillway, elevation 840.00 ft. Dead storage below elevation 720.00 ft, 2,387 mil gal. Figures given herein represent total contents. Reservoir impounds water from Rondout Creek; water diverted from Cannonsville Reservoir in the Delaware River basin through West Delaware Tunnel; water diverted from Pepacton Reservoir through East Delaware Tunnel; and water diverted from Neversink Reservoir through Neversink-Grahamsville Tunnel. Water is diverted (01366399) from Rondout Reservoir for New York City water supply through West Branch Tunnel of Delaware Aqueduct. Diversion began April 1944 by means of temporary emergency connection to aqueduct.
Capacity table (elevation, in feet, and total contents, in millions of gallons)

Elevation  Contents      Elevation  Contents
720.0      2,387         800.0      28,705
740.0      6,125         820.0      39,645
760.0     11,709         840.0      52,435
780.0     19,401         843.0      54,505
EXTREMES FOR PERIOD OF RECORD - Maximum contents observed, 54,346 mil gal, Apr. 3, 2005, elevation, 842.77 ft; minimum contents observed (after initial filling), 8,335 mil gal, Oct. 15, 1957, elevation, 748.75 ft.