LOCATION.--Lat 39°15'04.5", long 76°45'49.6", Baltimore County, MD, Hydrologic Unit 02060003, on left bank at highway bridge on Ilchester Road, 0.9 mi southwest of Catonsville, 2.0 mi southeast of Ellicott City, and 3.1 mi northeast of Columbia.
DRAINAGE AREA.--301 mi², from automated delineation using 30-meter National Elevation Dataset, digital elevation model data, dated 2006.
PERIOD OF RECORD.--October 2010 to current year.
PERIOD OF WATER QUALITY RECORD.--October 2010 to October 2021.
GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 66.20 ft above North American Vertical Datum of 1988.
REMARKS.--Flow regulated by Liberty Reservoir, approximately 18 mi upstream, beginning July 22, 1954, usable capacity, 42,070,000,000 gal; dead storage, 1,260,000,000 gal. Diversions upstream from station for municipal supply of Westminster (sewage effluent discharged into Little Pipe Creek), and from Liberty Reservoir beginning Feb. 26, 1953, for municipal supply of Baltimore, and beginning February 1970 for a small municipal supply for part of Carroll County. Turbidity values that are determined to be a result of debris on the sensor; a function of incident sun angle; or other phenomena that do not appear to be correlated to suspended-sediment concentration are removed by the hydrographer. U.S. Geological Survey satellite data-collection platform at station.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 25,500 ft³/s, July 30, 2016, gage height, 27.14 ft; minimum discharge, 29.0 ft³/s, Sept. 17, 2012.
COOPERATION.--Funding for the operation of this station is provided by the Baltimore County Department of Environmental Protection & Sustainability and the Maryland Department of Transportation.