- 48-Inch Raw Water Transmission Main
Lake Havasu City is developing a new water supply and treatment system. The Raw Water Transmission Main project provides for the conveyance of raw water from the new horizontal collector well and pump station to the biological removal treatment plant. The 48-inch diameter raw water line is concrete reinforced pipe. The nominal capacity of the line is 26 million gallons per day (MGD) and provides for transport of raw water from two additional wells in the system. The pipeline is 16,000 feet in length and includes 1,680 feet of 48-inch directional drilled steel pipe under the Bridgewater Channel, which is a man-made earthen channel just off the main body of Lake Havasu. This project includes two additional pipelines constructed by directional drilling: an 8-inch HDPE spare line adjacent to the 48-inch steel pipe and an 18-inch HDPE reuse line to transport treated effluent to the mainland for a reuse program.
This project involved numerous contacts with agencies for permit approval, including the U.S. Army Corps of Engineers, Arizona State Parks Department and Arizona Department of Transportation. Coordination with utilities was necessitated by the number of services provided along the pipeline corridor. An existing wastewater pump station and force main are adjacent to the 48-inch steel pipe, and Arizona regulations required that the 48-inch steel pipe be installed with maximum separation from these facilities. Since the pipeline is located in park property and adjoins residential areas, noise abatement, dust control, traffic control plans and working hours were all issues critical to the design of the system. Routing of the line through Windsor Beach State Park required construction to be conducted in a 30-foot right-of-way, which is minimal for the size of line being constructed.
The length and capacity of the pipeline required hydraulic surge analysis of the pipeline. Pressure relief valves at the pump station are required for system surge conditions that can be encountered during the operation of the system. Geotechnical conditions of the soils result in the need for restrained joints in place of thrust blocks at major restraint locations.
- Hydraulic analysis
- Construction administration