Water availability in Perry County, Alabama

Abstract

The principal sources of large quantities of ground water in Perry County are sand and gravel aquifers in the Coker, Gordo, and Eutaw Formations of the Upper Cretaceous Series. Upper Cretaceous deposits, which dip to the southwest at about 35 feet per mile, range in thickness (d from about 400 feet in the northern part of the county to about 2,300 feet in the southernmost part. Most wells tapping Upper Cretaceous deposits range in depth from 20 to 950 feet; the deposits are potential sources of water to depths of 2,000 feet. Yields of wells that tap individual aquifers in the Upper Cretaceous Series range from about 0.5 to 2 mgd (million gallons per day). Water levels in wells tapping the Upper Cretaceous deposits range from 40 feet above land surface in low areas along the streams to 245 feet below land surface in upland areas. Beds of sand and gravel in the alluvial deposits underlying the major stream valleys and terraces along these valleys are sources of water to wells. Where these beds are hydraulically connected to streams, they potentially will yield large supplies of water to wells. Annual rainfall averages about 55 inches and the average rate of runoff per square mile is about 0.8 mgd. The Cahaba River and Oakmulgee Creek are the largest sources of surface water in the county. The Cahaba River at Sprott has an average flow of about 1,300 mgd and a 7-day low flow (7-day Q 2 ) of 200 mgd. Cakmulgee Creek near Perryville has an average flow of about 140 mgd and a 7-day Q 2 of about 15 mgd. the total average flow of all streams in the county is about 1,300 mgd. Water from aquifers and streams in Perry County is chemically suitable for most uses. Water from wells ranges from soft to moderately hard but locally is hard and has an iron content that exceeds 0. 3 mg/l (milligrams per liter). Water from streams has a low mineral content and is generally soft. Water use in Perry County in 1968 was about 4 mgd which was less than 1 percent of the available quantity.