USGS Water-Year Summary 2021
01584050 LONG GREEN CREEK AT GLEN ARM, MD
LOCATION - Lat 39°27'16.9", long 76°28'44.0" referenced to North American Datum of 1983, Baltimore County, MD, Hydrologic Unit 02060003, on right bank 0.5 mi downstream from bridge on Glen Arm Road, 0.6 mi upstream from State Highway 147 (Harford Road), 0.8 mi east of Glen Arm, and 1.6 mi upstream from mouth.
DRAINAGE AREA - 9.40 mi².
PERIOD OF RECORD - October 1975 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 243.34 ft above North American Vertical Datum of 1988.