Littlerock Dam project gets back on track after weather setbacks
PALMDALE — The initial phase of a project to increase the storage capacity of the reservoir behind the Littlerock Dam has recovered from weather-related delays and is making good progress, Palmdale Water District Board of Directors learned Monday.
“They made a lot of progress in December,”
Engineering/Grant Manager Scott Rogers said.
Last fall, the District began construction on the project to remove sediment from the Littlerock Dam reservoir to increase its storage capacity, but the winter rains flooded the construction site and halted work for more than six months.
The contractor, ASI Construction, was able to return to the site in late
July and resume work, once they had brought it back to the point it was at when the work shut down. The process took nearly two months before construction work resumed in September.
Additional delays were encountered this fall when red flag warnings signalling high fire danger prevented construction work
from proceeding.
The grade control structure is at the finished height now, Rogers said.
However, a plug in the water line used to bypass the construction site failed over the weekend of Dec. 7, flooding the site. This will require about a week or two to dry out before construction may continue, he said.
Rogers said he expects the remaining items to be finished early next year, weather permitting.
The Littlerock Reservoir Sediment Removal Project has been in the works for some 25 years. The project calls for removing more than 1.16 million cubic yards of sediment that has built up behind the dam since 1992, reducing the water storage capacity by 500 acre-feet, according to District officials.
An acre-foot is 325,851 gallons, or approximately the amount of water a typical Antelope Valley household used in one year, before the most recent drought reduced usage.
The first phase is construction of a subterranean grade control structure, which began in October 2018.
The grade control structure is required before sediment removal may begin, in order to shore up the ground to prevent erosion once sediment is taken out of the stream.
The structure is a staircase dam that will be underground, under the water level of the reservoir. It will be built at a place called Rocky Point, where the stream that feeds the reservoir, Littlerock Creek, meets the high water mark, about one mile upstream from the dam.