This week our crews started installation of two drainage pipes which are 100 feet long and 18 inches in diameter. Why are these important?
A major component of earthen fill dams is to control water seepage. Seepage occurs with the continuous movement of water around and through the dam. Earthen fill dams are designed with filter drain materials. The new Calaveras Dam will have filter drains composed of sands and gravel materials, which are being imported to the project site. The filter drains collect the seepage. The water goes into the drainage pipes shown below and flows to a weir building, where it is measured continuously to ensure water is passing safely. Eventually the water will flow downstream to the nearby creeks. The completion of the Calaveras Dam is critical to restore the Calaveras Reservoir to its historic storage capacity of 31 billion gallons of water storage for the Hetch Hetchy Regional Water System.
Perforated Pipes being installed adjacent to the inspection well for the new Calaveras Dam
Installation of drainage pipes below the new spillway for the Calaveras Dam Replacement Project