USGS Water-Year Summary 2020
01403400 GREEN BROOK AT SEELEY MILLS, NJ
LOCATION - Lat 40°39'58", long 74°24'14" referenced to North American Datum of 1983, Watchung Borough, Somerset County, NJ, Hydrologic Unit 02030105, on right bank at Seeley Mills, 150 ft downstream from Blue Brook, 200 ft downstream from bridge on New Providence (Diamond Hill) Road, and 0.5 mi northwest of Scotch Plains.
DRAINAGE AREA - 6.23 mi².
- WDR NJ-81-1:1979(M). WDR NJ-87-1:1971(M), 1973(M), 1975(M).
PERIOD OF RECORD - Annual maximum gage, water years 1927-38, 1958-68 (in files of Union County Park Commission), and 1969-79. Fragmentary records 1944-53 (in the files of the U.S. Geological Survey). Occasional low-flow measurements, water years 1959-64, 1969. Continuous-record discharge station, June 1979 to current year.
GAGE - Water-stage recorder with telemetry and crest-stage gage. Datum of gage is 184.44 ft above NGVD of 1929. From 1944 to 1953, water-stage recorder and masonry dam about 500 ft downstream, above lower Seeley Mills dam at different datum. From July 1969 to May 1979, crest-stage gage about 550 ft downstream below lower Seeley Mills dam (washed out May 29, 1968) at different datum. From May 1979 to March 2019, water-stage recorder about 100 ft downstream at same datum.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of July 23, 1938 reached an elevation of 196.5 ft (New Jersey Geological Survey datum; above lower Seeley Mills dam), discharge, 5,840 ft³/s (computed by State Water Policy Commission).
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 6,240 ft³/s, Aug 2, 1973, gage height 16.10 ft, site and datum then in use; minimum discharge, 0.00 ft³/s, Sep 11, 1981.