The state Dept. of Water Resources reported that average precipitation for the northern Sierra region is 209 percent above average, making 2017 the wettest year on record. The snowfall coupled with the local rainfall captured in Del Valle Reservoir means Zone 7 will deliver all the requested water both this year and next year even if the drought returns in 2018. The forecast also says that the agency expects to meet demand through 2021.
Notably, demand in 2016 from local residents and businesses was only 60 percent of what had been forecast. It will be interesting to see how that trend continues this year when there is abundant water available.
Of course, water rates may play into that as well. Water rates this year include a 57-cent per cubic foot surcharge to rebuild Zone 7’s financial reserves that were depleted during the drought. It is scheduled to end after this year.
There’s also the huge challenge of rebuilding the spillway at Lake Oroville, the major dam that serves Zone 7 and the 28 other water agencies that contract with the Dept. of Water Resources for water. The state agency has issued a $275 million contract to rebuild or otherwise repair the heavily damaged spillway.
The feds will pick up 20 percent of that bill and perhaps more depending on disaster relief funds. The tab for the rest will go to the agencies such as Zone 7, which uses about 2 percent of the water supplied from Lake Oroville. The big bills will go to the Metropolitan Water District in Southern California and the two large ag districts in the San Joaquin Valley.
What’s truly unfortunate is, in this record year, there’s limited capability of storing the water. Voters passed a huge water bond in 2014 that included money for reservoirs. Have you seen construction on the Sites reservoir, which would be an off-river facility such as San Luis Reservoir near Los Banos? Building Sites would be beneficial for both water supply and for fish.
Water stored there can be released into the Delta for summer and fall supplies, allowing cold water to be held back in Lake Shasta where salmon spawn. Salmon eggs die if water temperatures reach the high 50s, so releasing cold water from Lake Shasta is important to maintaining the natural runs. That’s why Sites is a win-win environmentally and for water supplies. And, it dams no river.
The abundant water supply also offers agencies the opportunity to refill ground water basins. Zone 7 has managed the valley’s ground water basin for decades and routinely replenishes the basin during summer and fall months. That’s why some arroyos, that otherwise would dry up, run year-round.