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- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
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USGS Water-Year Summary 2025
14198500 MOLALLA RIVER ABOVE PINE CREEK, NEAR WILHOIT, OR
LOCATION - Lat 45°00'35.0", long 122°28'51.3" referenced to North American Datum of 1983, Clackamas County, OR, Hydrologic Unit 17090009, on right bank 0.5 mi upstream from Pine Creek, 5 mi southeast of Wilhoit, and at mile 32.5.
DRAINAGE AREA - 97 mi². at cableway 0.2 mi downstream.
REVISIONS HISTORY - Revisions: WSP 1738: Drainage area. WDR OR-75-1: 1967(M).
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1935 to September 1993, October 2023 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 791.35 ft above sea level (Bureau of Public Roads benchmark). Oct. 1, 1935, to Sept. 30, 1945, and Oct. 1, 1945, to Feb. 9, 1961, water-stage recorder at site 0.3 mid downstream at datums 8.42 and 10.44 ft lower, respectively. Feb. 10, 1961, to July 21, 1966, water-stage recorder at site 0.2 mi downstream at datum 5.99 lower.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 24,300 ft³/s Dec. 22, 1964, gage height, 16.3 ft, from floodmark, site and datum then in use, from rating curve extended above 5,200 ft³/s; minimum discharge, 16 ft³/s several days August to October 1992, but may have been lower during period of no record, July 25 to Aug. 31, 1992.
CLIMATOLOGICAL RECORDS
PERIOD OF RECORD - AIR TEMPERATURE: October 2023 to current year.
INSTRUMENTATION - Air temperature sensor and data logger.
EXTREMES FOR PERIOD OF RECORD - AIR TEMPERATURE: Maximum, 36.9°C July 9, 2024; minimum, -7.4°C Jan. 16, 2024.
WATER-QUALITY RECORDS
PERIOD OF DAILY RECORD - WATER TEMPERATURE: January 1964 to September 1969, October 2023 to current year.
INSTRUMENTATION - Water temperature sensor and data logger.
EXTREMES FOR PERIOD OF DAILY RECORD - WATER TEMPERATURE: Maximum, 24.0 °C July 30, 1963, Aug. 24, 2024; minimum, 1.0 °C Dec. 17, 18, 1965, and on several days during December 1968 and January 1969.
