LOCATION.-- At upstream side of bridge on State Highway 7, 1.0 mi southwest of White Marsh, and 3.0 mi upstream from mouth. PERIOD OF RECORD.--February 1959 to September 1989, March 1992 to current year. GAGE.--Water-stage recorder, crest-stage gage, and rock control. Datum of gage is 33.68 ft above North American Vertical Datum of 1988. From October 1, 2012 to April 14, 2022, datum of gage published as 33.71 ft above North American Vertical Datum of 1988. From October 1, 2004 to September 30, 2012, datum of gage was published as 34.52 ft above National Geodetic Vertical Datum of 1929. Prior to October 1, 2004, datum of gage published as 38.96 ft above National Geodetic Vertical Datum of 1929. September 30, 2004 to September 8, 2017, water-stage recorder at site 80 ft downstream on right wing wall at present datum. June 12, 2002 to September 30, 2004, water-stage recorder at site 2,500 ft upstream, on left downstream side of Interstate 95 box culvert at gage datum 4.44 ft higher. Prior to June 12, 2002, water-stage recorder at site on left bank, upstream side of Route 7 bridge at gage datum 4.44 ft higher. REMARKS.-- Low flow affected by operations of sand and gravel plant in vicinity of gage.