SURFACE-WATER RECORDS
LOCATION.--Lat 41°09'42", long 74°20'00" referenced to North American Datum of 1983, West Milford Township, Passaic County, NJ, Hydrologic Unit 02030103, in gatehouse near right end of Greenwood Lake Dam on Wanaque River at Awosting.
DRAINAGE AREA.--27.1 mi².
PERIOD OF RECORD.--June 1898 to November 1903, June 1907 to current year (gage heights only prior to October 1953).
REVISED RECORDS.--WDR NJ-94-1: 1993, WDR NJ-97-1: 1995-96.
GAGE.--Water-stage recorder with telemetry. Datum of gage is 608.86 ft above National Geodetic Vertical Datum of 1929 (levels from New Jersey Geological Survey benchmark). Prior to Oct 1, 1931, records provided by Morris Canal and Banking Company using staff gage on former railroad bridge at site 100 ft upstream at datum 89.75 ft lower.
REMARKS.--Reservoir is formed by earthfill dam with concrete spillway; dam completed about 1837 and reconstruction completed in 1928 with crest of spillway 0.25 ft lower. Usable capacity, 6,860,000,000 gal between gage heights -4.00 ft, sill of gate, and 10.00 ft, crest of spillway. Dead storage, 7,140,000,000 gal. Outflow mostly regulated by two gates, 3.5 by 5.0 ft. Records given herein represent usable capacity. Lake used for recreation. Diversions by North Jersey District Water Supply Commission from Upper Greenwood Lake enter Greenwood Lake via Green Brook. 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, 9,528,000,000 gal, Oct 9-14, 1903, gage height, 14.25 ft; minimum contents, 3,160,000,000 gal, several days in November 1900, gage height, 3.50 ft.