Groundwater Development Project - Predesign Study
To bring an alternative backup water supply to the Las Vegas Valley from eastern Nevada, the Southern Nevada Water Authority has initiated the crucial, high-profile Groundwater Development Project. Currently, the Valley receives almost all of its water from Lake Mead, which impounds Colorado River water. This source can no longer be relied upon to provide all the water needed by the fast-growing southern Nevada area, particularly under projected long-term drought conditions. This new groundwater source will be a sustainable alternative to Lake Mead, and will help secure southern Nevada's future water supply. The GWDP's initial concept included more than 200 miles of large-diameter main pipeline, up to 150 miles of collector pipelines, dozens of groundwater wells, five pumping stations, six regulating tanks, four hydroturbine stations to reduce head and generate electrical power, a terminal reservoir located in the Las Vegas valley, and a water treatment plant. The project's ultimate design flow ranges from 14 to 191 mgd.
In Phase 1, HDR's preliminary engineering design and hydraulic and surge analysis better defined the entire 200-mile main pipeline and further refined the alignment and appurtenant facilities for the southern 75 miles, including developing alignment alternatives to reduce overall environmental impacts and to lower construction costs. HDR also defined the system hydraulics in enough detail to establish the pipe wall thicknesses for the entire 200 mile length of the main pipeline. For this phase, HDR prepared a Hydraulic Analysis Report and a Draft Preliminary Design Report, which contains 28 technical memoranda to document the evaluations and decision process. Each technical memorandum addressed a specific technical issue, such as various pipeline realignments (including tunneling in certain locations); specific design criteria (such as pipeline material, coatings, linings, and corrosion control); and suggested alternative locations for certain pipeline facilities.