USGS Water-Year Summary 2019
01591700 HAWLINGS RIVER NEAR SANDY SPRING, MD
LOCATION - Lat 39°10'28.3", long 77°01'17.1" referenced to North American Datum of 1983, Montgomery County, MD, Hydrologic Unit 02060006, on right bank at downstream side of bridge on State Highway 650, 1.0 mi upstream from mouth, and 1.7 mi north of Sandy Spring.
DRAINAGE AREA - 27 mi².
PERIOD OF RECORD - June 1978 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 302.85 ft above North American Vertical Datum of 1988.