USGS Water-Year Summary 2023

03270500 GREAT MIAMI RIVER AT DAYTON OH

LOCATION - Lat 39°45'55", long 84°11'51" referenced to North American Datum of 1927, Montgomery County, OH, Hydrologic Unit 05080002, on left bank 1,000 ft downstream from Main Street bridge in Dayton, 0.7 mi upstream from Wolf Creek, 0.8 mi downstream from Mad River, at river mile 80.

DRAINAGE AREA - 2,511 mi².

REVISIONS HISTORY - WSP 1385: 1917. WSP 1908: Drainage area.

SURFACE-WATER RECORDS

PERIOD OF RECORD - April to September 1905, January to September 1906, January 1907 to December 1909 (gage heights only), April 1913 to current year. Monthly discharge only for October 1919 to September 1921, published in WSP 1305. Gage-height records collected at Main Street bridge since January 1892 are contained in reports of National Weather Service. Prior to October 1962, published as Miami River at Dayton.

GAGE - Water-stage recorder. Datum of gage is 669.15 ft (NAVD 1988). Prior to Oct. 1, 1921, nonrecording gage at Main Street bridge at 723.73 ft (1912 adjustment). Oct. 1, 1921 to July 24, 1931, nonrecording gage at same site at 721.00 ft (1912 adjustment). July 25, 1931 to Sept. 30, 2013 at current site at 700.00 ft (1912 adjustment), as requested by cooperator (699.71 ft NGVD 1929).

COOPERATION - Base data furnished by Miami Conservancy District.

REMARKS - Records fair for the 2014 water year except for estimated records, which are poor. Oct. 1, 2014 to Oct. 22, 2015: records fair except for estimated records, which are poor. Oct. 23, 2015 to Nov. 3, 2016: discharge records poor. Nov. 4, 2016 to Feb. 7, 2017: discharge records fair.  Feb. 8, 2017 to Oct. 8, 2017: discharge records rated fair. Oct. 9, 2017 to Apr. 4, 2018: discharge records poor. Apr. 5, 2018 to June 13, 2018: discharge records good. June 14, 2018 to Oct. 19, 2018: discharge records fair.

Flood flow regulated by four retarding basins upstream from station beginning in 1920, Huffman on the Mad River 6.4 mi upstream, Englewood on the Stillwater River 10.9 mi upstream, Taylorsville on the Great Miami River 10.9 mi upstream, and Lockington on Loramie Creek 41 mi upstream. Also, low flow slightly regulated by Lake Loramie, Indian Lake, and C.J. Brown Reservoir; see REMARKS for station 03261500, 03262000, and 03269500. Recharge to the wellfields for the City of Dayton and Montgomery County suburbs is largely induced infiltration from the Great Miami and Mad rivers. Groundwater pumpage upstream from the station is returned to the river as treated wastewater 4.8 mi downstream from the station, 9.3 mi downstream from the station, and a small amount diverted to the Little Miami River watershed through the county regional system. This pumpage could affect low flow.

Record quality ratings may not be included in the water-year summary for approved records newer than 09/30/2018. Record quality is still being rated internally. For questions about record quality ratings, please send email to gs-w-oh_NWISWeb_Data_Inquiries@usgs.gov.

Sediment data formerly collected at this site.

EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Mar. 26, 1913, reached a stage of 29.0 ft, site and datum then in use; discharge, 250,000 ft³/s, computed by Miami Conservancy District.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 60,900 ft³/s, Jan. 22, 1959, gage height, 36 ft, Jan. 22, 1959; minimum discharge, 109 ft³/s, Aug. 8, 1934.