USGS Water-Year Summary 2020
11465700 Colgan Creek near Sebastopol, CA
LOCATION - Lat 38°22'25", long 122°46'02" referenced to North American Datum of 1927, Sonoma County, CA, Hydrologic Unit 18010110, in Llano de Santa Rosa Grant, on left bank, downstream side of Llano Road bridge, 0.5 mi upstream of Laguna de Santa Rosa, and 3.5 mi southeast of Sebastopol.
DRAINAGE AREA - 6.78 mi².
PERIOD OF RECORD - November 1998 to current year.
GAGE - Water-stage recorder and velocity meter. Datum of gage is NGVD of 1929.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 934 ft³/s, Dec. 31, 2005, gage height, 79.21 ft; no flow for many days in each year.