STATION.--01574700 INDIAN ROCK DAM NEAR YORK, PA
LOCATION.--Lat 39`55'22", long 76`45'14", York County, Hydrologic Unit 02050306, at dam on Codorus Creek, 0.1 mi upstream from mouth of South Branch Codorus Creek, 0.3 mi west of York Water Co. pumping station, and 3.0 mi southwest of York.
DRAINAGE AREA.--93.7 square miles.
PERIOD OF RECORD.--September 1962 to current year in reports of Geological Survey, September 1942 August 1962 in files of Baltimore District, U.S. Army Corps of Engineers.
GAGE.--Water-stage recorder and heated tipping bucket precipitation gage. Datum of gage is U.S. Army Corps of Engineers local project datum. Prior to water year 2007, the datum was incorrectly reported as NGVD 1929. Satellite telemetry at station.
REMARKS.--Reservoir formed by an earth and rockfill dam with ungated concrete spillway at elevation 435.00 ft (capacity, 28,000 acre-ft). Reservoir completed in June 1942; storage began in June 1946. No dead storage. Reservoir is used for flood control. Flood storage is regulated by three vertical- lift tractor gates. Water is stored only during high flows and released when downstream conditions warrant.

The 15-minute precipitation data for this station are temporary and will only be displayed for 120 days. Time series of 1-hour or cumulative daily values will NOT be available for retrieval following the 120-day display period. Although the instrumentation is calibrated at least once a year, the temporary classification means that documented routine inspections and other quality assurance measures are not performed that would make the data acceptable for archival, retrieval, or future use in general scientific or interpretive studies.

COOPERATION.--Funding for the operation of this station is provided by the U.S. Army Corps of Engineers, Baltimore District.