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The Yazoo River Basin (see figure) covers an area of about 13,400 square miles in northwestern Mississippi. The basin is about 200 miles long and has a maximum width of about 110 miles. The basin includes a hilly upland in north-central Mississippi where four headwater tributaries originate, and an extensive flat lowlands in the Mississippi River Alluvial Plain, commonly referred to as the Delta. Major streams in the basin include the Big Sunflower, Coldwater, Tallahatchie, Yalobusha, Yazoo, and Yocona Rivers. These rivers eventually empty into the Mississippi River. Elevations in the Yazoo River Basin range from about 50 to almost 700 feet (14 to 210 meters) above sea level. The Delta constitutes an area of almost 7,000 square mile of some of the most fertile and productive farmland in the world. Most of the Delta consists of relatively large farms that produce cotton, corn, soybeans, and rice; about 100,000 acres are devoted to catfish farming. The upland part of the basin consists largely of forests, pastures, and small farms and is sparsely populated. About 36 percent of the basin is forested, and about 58 percent is agricultural land.  Historical average, maximum, and minimum stream discharge data are not available for the Yazoo River Basin. However, a stream gage has recently been established that will be able to provide this information. Use of surface water in the Yazoo River Basin is large. About 76.4 million gallons per day are used for irrigation, about 2.2 million gallons per day are used for livestock, and about 23.4 million gallons per day are used for industry. However, an average of about 2 billion gallons of ground water per day are pumped from the aquifer beneath the basin--far more than all of the State's surface water use combined. Streams in the upland part of the basin tend to have muddy or sandy bottoms with sluggish to moderate flow, and water quality is generally fair. Streams in the Delta are typically sluggish with silty bottoms. Many of the streams receive large amounts of sediment and other agricultural contaminants resulting in high turbidity, elevated nutrients, and periodically elevated toxics resulting in fair to poor water quality. |