USGS to Develp Indicators to Better Measure Nation's H2O Supply: Greenwire

Home Browse Search

the region primarily used for irrigation, are a major concern in Arkansas and Mississippi. Water -level declines in the Mississippi River Valley Alluvial have changed the surface - water /ground -water relationship resulting in a significant reduction of base flows in streams. For example, typical base flow in the Sunflower River in Mississippi is only about 10 percent of historical base flow. The Sparta aquifer and its equivalents have been primary sources of high quality water for many industrial and municipal users throughout Arkansas, Louisiana, Mississippi, and Tennessee. Continued pumping from the Sparta aquifer since the 1920's has caused significant water -level declines in the region. Such declines have resulted in the aquifer being declared "critical" in Arkansas and nominated for "critical" status in Louisiana. Other areas in the region also are heavily dependent on ground water for public supply and industrial purposes. For example, Memphis, Tennessee and West Memphis, Arkansas is one of the largest metropolitan areas in the world that relies exclusively on ground water for municipal supply. This heavy reliance on ground water has resulted in interstate concerns over continued and increased pumpage in the Memphis area. 9 Souris- Red -Rainy Region - -The Souris- Red -Rainy Region is located along the northern boundary of the United States in Minnesota and North Dakota, and extends short distances into South Dakota and Montana. The region drains northward into the Hudson Bay of Canada. It consists of three basins: the Souris River on the west; Red River of the North in the center; and Rainy River on the east. Continental glaciers left a poorly drained landscape of broad, flat plains along the center of the region surrounded by gently rolling uplands, lakes, potholes, and wetlands. Many areas do not contribute to stream outflow, but comprise closed basins. Precipitation varies greatly across the region resulting in average annual runoff that ranges from 0.2 inches in the western part of the Souris to about 10 inches in the eastern part of the Rainy Basin. Ground water, derived primarily from disconnected sand and gravel aquifers throughout the region and from sedimentary rocks in the western part of the region, is sufficient to support rural water supply and some irrigation of crops. Surface and ground water are sufficient for public supply, light industrial uses and in the heavily forested Rainy Basin for recreational use. Population growth of the region is most significant along the Red River of the North, which is beginning to stress water availability from surface and ground waters. This stress is raising the level of debate about the transfer of water from the Missouri River and potential effects on downstream users regarding water quality and introduced biota. 10 Missouri River Region - -On the mainstem of the Missouri River, navigation interests compete with environmental interests on the timing and amounts of water in the lower river. In addition, recreational interests associated with large reservoirs in the upper basin States contend with navigation interests in the lower basin States for water during droughts. Recreational interests in the upper basin need stable water levels in reservoirs and navigation interests need to draw down reservoirs to provide enough flow for navigation downstream of Sioux City, IA. Several lawsuits are pending in the federal courts on these issues. Numerous other water availability issues exist within this large and diverse basin. The most visible ground -water issues are associated with the High Plains aquifer, which occurs throughout the southern part of the basin. Extensive 19