PROVISIONAL DATA SUBJECT TO REVISION

Station operated in cooperation with Portland General Electric.

14210000  CLACKAMAS RIVER AT ESTACADA, OR

LOCATION.--Lat 45° 18'00", long 122° 21'10", in NE 1/4 sec.19, T.3 S., R.4 E., 
   Clackamas County, Hydrologic Unit 17090011, on left bank 0.2 mi downstream 
   from River Mill Dam, 1.5 mi northwest of Estacada, and at mile 23.1.
DRAINAGE AREA.--671 mi2.
PERIOD OF RECORD.--April 1908 to current year. Monthly discharge only 
   April 1908, published in WSP 1318. Published as "near Cazadero" January 1909 
   to September 1957.
GAGE.--Water-stage recorder. Datum of gage is 286.93 ft above NGVD of 1929 
   (levels by Portland General Electric Co.). Water-stage recorder at same 
   site at datum 12.00 ft higher. Feb. 17, 1965 to Sept. 30, 1991, water-stage 
   recorder at same site at datum 10 ft higher.
REMARKS.--Diurnal fluctuations and some regulation caused by powerplants 
   at River Mill Dam and, since 1958, North Fork Dam. Minor regulation since 1956 
   by Timothy Lake (station 14208600). One small diversion upstream from station 
   for city of Estacada municipal water supply.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 86,900 ft3/s Dec. 22, 1964, 
   gage height, 18.36 ft (present datum); minimum discharge, 50 ft3/s 
   Mar. 10, 1961, from rating curve extended below 260 ft3/s; minimum daily, 
   285 ft3/s Oct. 4, 5, 1958, caused by filling of North Fork dam forebay.

NOTE: The most current shifted rating for this site can be found at USGS Rating Depot website.