Click
to
hide
Water-Year
Summary
instructions
and
information
- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
- For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
- Not all sites have reports available for every water year.
USGS Water-Year Summary 2025
12421500 SPOKANE RIVER BELOW TRENT BRIDGE NEAR SPOKANE, WA
LOCATION - Lat 47°41'50", long 117°14'35" referenced to North American Datum of 1927, Spokane County, WA, Hydrologic Unit 17010305, On right bank half a mile downstream from Trent Bridge and 9 miles east of Spokane.
DRAINAGE AREA - 4,200 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - January 1948 to September 1954 (continuous-record); July 2010 to November 2014 (seasonal records).
GAGE - Water-stage recorder. Datum of gage is 1,907.49 ft above mean sea level (levels by Bureau of Reclamation). Prior to Dec. 4, 1948, at site 20 ft upstream at same datum.
REMARKS - Flow partly regulated by power plants of the Avista Corporation at Spokane, Washington and Post Falls, Idaho and by storage in Coeur d'Alene Lake, Idaho.
- Water Year 2014: No estimated daily discharges. Records good.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum discharge, 41,800 ft³/s, May 31, 2008, from upstream site 12420500 Spokane River at Greenacres, Wash.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 40,100 ft³/s May 30 or 31, 1948, gage height, 18.50 ft (from high water mark on gage); minimum discharge, 578 ft³/s, Aug. 26, 2010, gage height, 4.16 ft.
AVERAGE DISCHARGE FOR PERIOD OF RECORD - 6 years (1949-1954), 7,331 ft³/s, 5,311,000 acre-ft/yr.
