PALMDALE — The wet winter may have been a good thing for water supplies, but the rain did create some expensive problems for the Palmdale Water District.
Last fall, the District began construction on a project to remove sediment from the Littlerock Dam reservoir to increase its storage capacity, but the winter rain flooded the construction site and halted work for more than six months.
On Monday, the District’s Board of Directors unanimously approved a nearly $1.12 million addition to the contract with ASI Construction to cover the additional costs of securing the site and removing equipment during the shutdown and the delay.
“That was quite a stretch where the contractor was being billed and paying for things that he was not getting reimbursed from us,” Project Manager Peter Thompson said.
The contractor returned to the site in late July and is now working to bring it to the point it was at when work shut down. That process is expected to be completed in about three weeks.
The costs related to that process will be another change order to the contract, Thompson said.
It is believed that at least a portion of the recovery costs will be covered by the contractor’s insurance.
“We don’t know yet what it’s going to be,” Thompson said. “They are confident that the insurance will pay the maximum for that part of it.”
The additional money required for the construction project is available from the bond issue used to pay for it, although it may mean that other potential projects listed under that bond issue will be postponed, General Manager Dennis LaMoreaux said.
The addition approved Monday, brings the project cost back up to the original contract price, before reductions were made to bring it more in line with the original estimate of the project cost, he said.
The contract period will also be extended by 234 days to account for the lost time.
The recreation area at the dam remains closed to the public by the U.S. Forest Service until February 2020, in order to allow the construction work and initial removal to take place.
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 the construction of a subterranean grade control structure, which began in October.
It 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.