Water Resources. 1. Hydrologic Cycle and Water Reservoirs 2. Floods and Flood Control 3. Use of Water 4. Water Composition 5. Water Problems. Who Owns the water?. Surface Water Riparian Rights in the Eastern U.S. Prior Appropriation in the Western U.S. Ground Water
Locations in the basins of southern California, Nevada, Utah, Arizona, and New Mexico where substantial ground-water level declines have been measured. In some areas, water levels have recovered in response to reduction in pumping and increased recharge efforts (Leake and others, 2000).
This earth fissure formed on Rogers Lake at
Edwards Air Force Base, California, in January
1991, and forced the closure of one of the
space shuttle’s alternative runways. The fissure
has been attributed to land subsidence
related to ground-water pumping in the Antelope
Valley area (Galloway and others, 2003).
When fresh water is withdrawn at a faster rate than it can be replenished, a drawdown of the water table occurs with a a resulting decrease in the overall hydrostatic pressure. When this happens near an ocean coastal area, salt water from the ocean intrudes into the fresh water aquifer as shown in the diagram. The result is that fresh water supplies become contaminated with salt water as is happening to communities along the Atlantic and Gulf coasts.
Figure 10. Along parts of the Atlantic coast from Maine to Massachusetts, broad lowland areas were flooded by the sea during the close of the last period of glaciation, approximately 12,000 to 13,000 years ago. This flooding occurred in areas that were temporarily depressed below sea level by the immense weight of the glacial ice (Olcott, 1995). As the glaciers retreated and before the land surface rebounded above the present sea level, there was a period during which seawater submerged these lowland areas, and saltwater intruded the unconsolidated sediments and fractured bedrock that formed the inland seafloor. After the land surface rebounded and the ocean receded, freshwater replaced this saline ground water in most areas. However, in some regions of relatively slow ground-water circulation, the saltwater has been trapped in the sediments and bedrock for about 12,000 years (Tepper, 1980; Snow, 1990). Several wells in Maine that are distant from the coast have yielded water with high chloride concentrations that have been attributed to this trapped seawater.