SURFACE-WATER RECORDS
LOCATION.--Lat 41°02'42", long 74°17'43" referenced to North American Datum of 1983, Wanaque Borough, Passaic County, NJ, Hydrologic Unit 02030103, at Raymond Dam on Wanaque River at Wanaque, 1,700 ft upstream of bridge on County Route 511 (Ringwood Avenue), and 3.3 mi north of Riverdale.
DRAINAGE AREA.--90.4 mi².
PERIOD OF RECORD.--February 1928 to current year. Monthend contents only, February 1928 to September 1950, published in WSP 1302, October 1951 to September 1960 published in WSP 1722, October 1950 to September 1953 also published in Special Report 16 (New Jersey Department of Environmental Protection); Monthend elevation and contents only, October 1961 to September 1995 published in Annual Water Data Reports.
REVISED RECORDS.--WDR NJ-85-1: 1984 (M). WRD US-2013: Usable capcity.
GAGE.--Water-stage recorder with telemetry. Datum of gage is National Geodetic Vertical Datum of 1929 (levels by North Jersey District Water Supply Commission).
REMARKS.--Reservoir is formed by earthfill with concrete-core wall main dam and seven secondary dams; dams completed in 1927 and storage began in March 1928. Total capacity at spillway level, 29,630,000,000 gal, elevation, 302.4 ft, prior to 1986, 300.3 ft. Available capacity at spillway level, 29,488,000,000 gal (revised). Outflow mostly controlled by sluice gates in intake conduits in gatehouse. Water is diverted from reservoir for municipal supply. Diversion to reservoir from Posts Brook, Pompton River, and Ramapo River. Records given herein represent total capacity. 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, 31,280,000,000 gal, Apr 5, 1984, elevation, 304.52 ft; minimum contents, 5,110,000,000 gal, Dec 26, 1964, elevation, 256.06 ft.

Occasionally the reservoir levels appear to be several tenths of a foot too low due to possible drawdown caused by use of water supply intakes at certain levels.