Monitoring location Patapsco River Near Catonsville, MD - USGS-01589025

LOCATION.--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. PERIOD OF RECORD.-- October 2010 to current year. GAGE.-- Water-stage recorder and crest-stage gage. Datum of gage is 66.34 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 February 26, 1953, for municipal supply of Baltimore, and beginning February 1970 for a small municipal supply for part of Carroll County. PERIOD OF DAILY RECORD (Water Quality).-- TURBIDITY: October 2010 to October 2021 SEDIMENT CONCENTRATION: October 2010 to October 2021. SEDIMENT LOAD: October 2010 to October 2021. REMARKS (Water Quality).-- Sediment discharge loads and concentrations were estimated for days of estimated daily discharges. Turbidity values greater than 1,600 nephelometric turbidity units (NTU) exceed the instrument calibration range. Values are included in the record but are presumed to have lower precision. Turbidity values that were determined to be a result of debris on the sensor, a function of incident sun angle, or other phenomena that did not appear to be correlated to suspended-sediment concentration were removed by the hydrographer.