LOCATION.--Lat 38°54'12.1", long 77°04'03.6", Washington, DC, Hydrologic Unit 02070010, on left bank at upstream end of Georgetown Waterfront Park, 0.60 mi upstream from mouth of Rock Creek, 0.08 mi downstream from Key Bridge, and at river mile 112.5. DRAINAGE AREA.--Not determined. PERIOD OF RECORD.--October 2009 to current year. GAGE.--Water-stage recorder. Datum of gage is 0.00 ft above North American Vertical Datum of 1988 (NAVD88).
October 1, 2009 until September 30, 2013, datum of gage was 0.00 ft above National Geodetic Vertical Datum of 1929 (NGVD29). Washington Mean Low Water Datum (WMLW) is +2.26 ft above NAVD88. EXTREMES OUTSIDE PERIOD OF RECORD.--Maximum tidal gage height, 16.31 ft NGVD29 (17.72 ft WMLW), Oct. 17, 1942; Minimum unknown. EXTREMES FOR PERIOD OF RECORD.--Maximum elevation, 9.01 ft NGVD29, March 15, 2010; minimum elevation, unknown (stage dropped below minimum recordable level on Feb. 15, 2015). REMARKS.--This is a tidal station. Discharge is not determined at this location. U.S. Geological Survey satellite data-collection platform at station. COOPERATION.--Funding for the operation of this station is provided by the U.S. Army Corps of Engineers.