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 mi
2, 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.
This page is undergoing modernization with expected decommissioning as key features
are added to the modernized pages. 
