USGS Water-Year Summary 2021
11025500 Santa Ysabel Creek near Ramona, CA
LOCATION - Lat 33°06'25", long 116°51'55" referenced to North American Datum of 1927, in NW 1/4 NE 1/4 sec.27, T.12 S., R.1 E., San Diego County, CA, Hydrologic Unit 18070304, on left bank, 1.6 mi downstream from Temescal Creek, 4.5 mi north of Ramona, and 5.0 mi downstream from Sutherland Reservoir.
DRAINAGE AREA - 112 mi².
- WSP 1928: Drainage area.
PERIOD OF RECORD - February 1912 to February 1923 (monthly discharge only for November and December 1919), October 1943 to current year.
GAGE - Water-stage recorder and concrete control. Datum of gage is 847.88 ft above NGVD of 1929 (levels by city of San Diego Water Department). See WSP 1315-B for history of changes prior to Feb. 3, 1923.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 28,400 ft³/s, Jan. 27, 1916, gage height, 14.0 ft, datum then in use, from rating curve extended above 1,500 ft³/s, on basis of slope-conveyance study of peak flow, maximum gage height, 14.25 ft, Feb. 21, 1980; no flow at times in some years.