A07_-_IMCOM_OPORD_17-036_(HWAD-Cat_Creek).pdf

extends along the upstream toe. 3 inch porous concrete tile drains at 3 foot centers are located 3 feel downstream from the upstream face. These drains extend the entire height of the d�tm and will intercept seepage through the dam. A9 inch copper water stop located 12 inches from the surf ace extends vertically along the entire upstream and downstream face al each vertical monolith joint.

Outlet \Vorks- The outlet works is located in the center of the dam and consists of 9 valves on the upstream face which are controlled from the top of the dam and 5 valves in control houses on the downstream face. Of the 9 valves, five 6 inch valves are located on the 6 inch outlet pipe and four 12 inch valves are located on the 12 inch outlet pipe. The 2 valves for the 6 inch pipe am.I the 2 valves for the 12 inch pipe are located in the small control house on the downstream face. In addition to the 6 inch pipe and the I 2 inch pipe, there is a 36 inch outlet pipe. The valve for the 36 inch pipe is located in the large control house on the downstream face. The order in which these valves were installed is as follows:

1932 The dam was completed and the 2 valves for the 6 inch pipe and the 2 valves for the I� inch pipe were installed. Both pipes were capped at the bottom of the upstream face

1933 Five 6 inch valves, a 6 inch pipe and protective screen were added to the upst.ream face.

The 6 inch pipe was connecled to the existing 6 inch pipe through the dam.

1942 Three IO inch valves. one 12 inch valve and a IO inch pipe were added to the upstream face and connected Lo the existing 12 inch pipe through the dam. The 12 pipe and valve were surrounded by a protective screen.

1955 The three 10 inch valves, and the one 12 inch valve were replaced with new 12 inch valves. The IO inch pipe was replaced with a 12 inch pipe.

1958 A 36 inch pipe and valve were installed through the dam. Sediment deposited during a cloudburst was subsequently sluiced through this valve. Presently water is released through the 12 inch pipe and conveyed to Black Beauty reservoir 2 miles downstream for treatment.

Spillwav The overflow section of lhe dam is depressed 18 inches below the top of dam and has a length of 50 feet. The spillway capacity is 255 cubic feet-per-second (cfs).

Size Classification - The dam has a strnctural height of 97feet and a capacity of 155 acrefeet. The size classification is large.

Ownership - U.S. Army. The dam was built by the U.S. Navy, Bureau of Yards and Docks on U.S. Navy property. At that time it was - a Naval Ammunition Depot. but subsequently the property was transferred to the U.S. Army in Oct 77 and it became an Army Ammunition Depot.

Purpose - The project provides a portion of the potable water -;upply for Hawthorne Army Ammunition Depot.