USGS Water-Year Summary 2024

01574000 WEST CONEWAGO CREEK NEAR MANCHESTER, PA

LOCATION - Lat 40°04'50.9", long 76°43'06.21" referenced to North American Datum of 1927, York County, PA, Hydrologic Unit 02050306,

on left bank 500 ft upstream from bridge on State Highway 181, 0.6 mi downstream from Little Conewago Creek, and 1.5 mi north of Manchester. On Sept 13, 2017 the gage was relocated to Lat 40° 04' 50.9", long 76° 43' 6.21" referenced to North American Datum of 1983, York County, PA, Hydrologic Unit 02050306, on right bank 80 ft upstream from bridge on State Highway 181, 0.7 mi downstream from Little Conewago Creek, and 1.5 mi north of Manchester.

DRAINAGE AREA - 510 mi².

REVISIONS HISTORY - WSP 741: Drainage area. WSP 1502: 1930, 1936.

SURFACE-WATER RECORDS

PERIOD OF RECORD - October 1928 to current year. Prior to October 1931, published as Conewago Creek near Manchester.

GAGE - Water-stage recorder, crest-stage gage and water-quality monitor. Datum of gage is 262.89 ft above North American Vertical Datum of 1988 (from benchmark).  Prior to April 3, 2025, the datum of gage was reported as 263.68 ft above National Geodetic Vertical Datum of 1929. Satellite telemetry at station.

COOPERATION - Station established and maintained by the U.S. Geological Survey. Funding for the operation of this station is provided by the Pennsylvania Department of Environmental Protection and the U.S. Geological Survey.

REMARKS - Occasional slight regulation since October 1959 by Conewago Lake about 13 mi upstream, capacity, 3,570 acre-ft. Also, occasional releases from Lake Meade about 30 mi upstream, 0.42 sq mi. Records for water year 2014 are good, except those for the discharges from 470 ft³/s to 9,650 ft³/s, which are fair, and those for estimated daily discharges, which are poor. Records for water years 2015-2016 are good except those for the discharges less than 200 ft³/s, which are fair, and those for estimated daily discharges, which are poor. Records for water year 2017 are good except those for the discharges less than 200 ft³/s, which are fair, and for estimated discharge, which is poor. Records for water years 2018-2024 are fair except for estimated discharge, which is poor.

EXTREMES FOR PERIOD OF RECORD -

Since the 1928 start of recorded through current analyzed period:

The Station's Peak of Record (POR) remains 96,200 cfs which occurred at GH of 32.11 ft on 9/26/1975.
Highest computed DV from 9/26/1975 remains 64,000 cfs.

WATER-QUALITY RECORDS

PERIOD OF RECORD - March 1962 to September 2019.

PERIOD OF DAILY RECORD - Water Temperature: November 2019 to current year. Specific Conductance: November 2019 to current year. pH: November 2019 to current year. Dissolved Oxygen: November 2019 to current year. Turbidity: November 2019 to current year. Nitrate: June 2020 to current year.

COOPERATION - Station established and maintained by the U.S. Geological Survey. Funding for the operation of this station is provided by the York County Water Quality Monitoring Project.

INSTRUMENTATION - A YSI EXO2  collects water temperature, turbidity, specific conductance, dissolved oxygen and pH at a 15-minute interval.

EXTREMES FOR PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: Maximum, 943 microsiemens/cm, Jan 17, 2022; minimum, 79 microsiemens/cm, Aug 19, 2021. pH: Maximum, 9.5, May 14, 2021; minimum, 6.8, Aug 10, 2024. WATER TEMPERATURE: Maximum, 32.6 °C, Jul 6, 2020 and Jun 29, 2021; minimum, -0.1°C, many days. DISSOLVED OXYGEN: Maximum, 19.3 mg/L, Oct 21, 2024 and Dec 14, 2022; minimum, 2.4 mg/L, Jun 22, 2024; TURBIDITY: Maximum, 685 FNU, Mar 4, 2023; minimum, <0.3 FNU, many days.