USGS Water-Year Summary 2023

08063050 Navarro Mills Lake near Dawson, TX

LOCATION - Lat 31°57'27", long 96°41'21" referenced to North American Datum of 1927, Navarro County, TX, Hydrologic Unit 12030108, in left abutment of spillway of Navarro Mills Dam control room, on Richland Creek, 1.7 mi upstream from bridge on State Highway 31, 3.0 mi upstream from St. Louis Southwestern Railway Lines bridge, 4.2 mi upstream from Post Oak Creek, 4.6 mi. north of Dawson, and 63.9 upstream from mouth. 

DRAINAGE AREA - 320 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD - Sept. 1962 to Sept. 2000 (U.S. Army Corps of Engineers furnished contents), Oct. 2000 to Sept. 2002 (contents), Oct. 2002 to current year. Prior to Oct. 1970, published as "Navarro Mills Reservoir". PERIOD OF RECORD, Water-Quality.-- CHEMICAL DATA: Aug. 1965 to Aug. 1980.

GAGE - Water-stage recorder. Datum of gage is 0 ft above NGVD of 1929 and 0.10 below NAVD of 1988. To obtain elevation values in NAVD 1988, add 0.10 ft. Prior to Oct. 8, 1962, nonrecording gage in low-water channel at same datum. Satellite telemeter at station.

REMARKS - Some records listed in the "Period of Record" for surface water and water quality may not be available electronically. The lake is formed by a rolled earthfill dam 7,570 ft long, including a 240-foot off-channel gated spillway with six 40.0- by 29.0-foot tainter gates. From Aug. 27, 1962, to Mar. 14, 1963, lake was operated as a detention basin only. Deliberate impoundment began Mar. 15, 1963, and dam was completed in Sept. 1963. Low-flow outlet works consist of two 36-inch-diameter gate-controlled conduits. Lake was built for flood control and water conservation. Flow is affected at times by discharge from the flood-detention pools of 51 floodwater-retarding structures with a combined detention capacity of 26,160 acre-ft. These structures control runoff from 86.9 mi² in the Richland Creek drainage basin. The dam is owned by the U.S. Army Corps of Engineers. An unknown amount of water is diverted for municipal and industrial uses. Data regarding dam are given in the following table:

                                                            Elevation (feet)                                      
Top of dam..........................................             457.0      
Design flood..........................................           451.9
Top of gates (top of flood-control storage pool).......          443.0
Crest of spillway (gate sill).........................           414.0
Lowest gated outlet (invert)...........................          400.0

Water-quality records available from Mar. 1981 to Sept. 2006 were published separately as:

Site ID                Site name
315730096412601  Navarro Mills Lk Site AC nr Dawson, TX
315706096420201  Navarro Mills Lk Site AR nr Dawson, TX
315710096431301  Navarro Mills Lk Site BC nr Dawson, TX
315642096444401  Navarro Mills Lk Site CC nr Dawson, TX
315602096470001  Navarro Mills Lk Site DC nr Dawson, TX
315706096463201  Navarro Mills Lk Site EC nr Dawson, TX

EXTREMES FOR PERIOD OF RECORD - Maximum contents, 183,300 acre-ft, May 18, 1968, elevation, 440.36 ft; maximum elevation, 443.37 ft, Oct. 31, 2015; minimum contents since initial filling in May 1965, 32,490 acre-ft, Dec. 28, 1978, elevation, 418.89 ft; minimum elevation, 415.73 ft, Dec. 19-20,23-24,28-29, 2006.

WATER-QUALITY RECORDS

PERIOD OF RECORD - CHEMICAL DATA: Oct. 1969 to Sept. 1982, Oct. 1999 to Sept. 2004. BIOCHEMICAL DATA: Oct. 1981 to Aug. 1982, Oct. 1999 to Sept. 2004. PESTICIDE DATA: Aug. 2000 to Sept. 2004.

REMARKS - Pesticide samples are composited from discrete samples collected at the surface, middle, and bottom of the reservoir.