During winter months, cold and ice may result in inaccurate real-time lake or reservoir elevation data. Adjustments or deletions of this data can only be done after detailed analysis.

 

SURFACE-WATER RECORDS
LOCATION.--Lat 41°01'06", long 74°00'04" referenced to North American Datum of 1983, Old Tappan Borough, Bergen County, NJ, Hydrologic Unit 02030103, at dam on Hackensack River, 0.5 mi north of Old Tappan, and 3.0 mi upstream from gaging station Hackensack River at Rivervale, NJ (01377000).
DRAINAGE AREA.--49 mi².
PERIOD OF RECORD.--From October 1966 to October 2010, month-end elevation and contents were provided by United Water New Jersey. Continuous-record reservoir station, 2011 to current year. 
REVISIONS HISTORY.--WDR NJ-88-1: Capacity, WDR NJ-99-1: 1998 (elevation, contents).
GAGE.--Water-stage recorder with telemetry. Datum of gage is NGVD of 1929.
COOPERATION.--United Water New Jersey.
REMARKS.--Reservoir is formed by earthfill dam, completed in 1966. Capacity, 3,853,000,000 gal, elevation, 55.00 ft at top of Bascule gates. Flow regulated by four Bascule gates and one sluice gate. Water is released for diversion at New Milford and Oradell Reservoir at Haworth by United Water New Jersey for municipal water supply. Annual extremes beginning in water year 2014 can be obtained by using this link. Prior to water year 2014, annual extremes can be obtained on the respective annual water year summary.
EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 4,120,000,000 gal, Aug 28, 2011, gage height 55.73 ft; minimum contents 1,240,000,000 gal, Jan 10, 2011, gage height 46.35 ft.