New Melones Dam, shown during better hydrologic times, impounds New Melones Lake on the Stanislaus River. Photo by the U.S. Bureau of Reclamation.
State officials will allow water quality in the Stanislaus River to deteriorate in order to hold back more water for later in upstream New Melones Reservoir.
The decision this week by the executive officer of the State Water Resources Control Board comes despite an earlier warning from environmentalists that lower levels of dissolved oxygen “will be devastating to many species of fish that encounter such conditions” and “could cause a near or total failure of adult fall run salmon migration on the Stanislaus River and other tributaries of the San Joaquin.”
The decision on dissolved oxygen (“DO” for short) is just the latest in a series of similar relaxations of water quality standards across the Central Valley as officials chose between bad and worse actions during this fourth year of drought.
Officials have also temporarily weakened rules about how much water should be allowed to flow through the fragile Delta. And they are allowing warmer temperatures on the upper Sacramento River, which may jeopardize endangered winter-run Chinook salmon. This has all been done under emergency authority from Gov. Jerry Brown, bypassing the normal process required for such changes.
But back to the matter at hand: The Stanislaus River.
Just like humans, fish need oxygen to breathe. Theirs is dissolved in the water. Low DO, therefore, can be bad for fish.
Normally the U.S. Bureau of Reclamation, which operates New Melones as part of the Central Valley Project, must release enough water to achieve DO levels of at least 7.0 milligrams per liter on the Stanislaus River at Ripon. The new change will allow that number to fall to 5.0 mg/L through the end of November, a less ambitious target that allows the feds to release less water.
Tom Howard, executive officer of the water board, laid out New Melones’ sad condition in a document approving the plan. The reservoir is about 15 percent of capacity and 24 percent of normal, he wrote; things haven’t been this bad since the drought of the early 1990s.
Only about 300,000 acre-feet of water drained into the reservoir this year, the worst since New Melones was constructed in the 70s. And later this year the reservoir level may drop below the level required to run water through the power generators.
Farmers in the area are already receiving the lowest deliveries allowed under their contracts, and other more junior users — including the Stockton East Water District — didn’t get any New Melones water this year. In short, the feds say there is no way to meet DO requirements now and save water in the reservoir to help fish later this fall.
Howard agreed, finding there was an “urgent need” to weaken the standard, to “reserve critical water supplies that will be needed to provide minimal protection to the Stanislaus River fishery later in the year and for water supply purposes for various uses going into next year.” He acknowledged there will be impacts to fish, but said those impacts are “not unreasonable.” Some fish have likely already left the river; others will still be able to find suitable habitat farther upstream from Ripon, closer to New Melones, where DO levels will presumably be higher.
Howard did require Reclamation to write an operations plan for New Melones for next year, in an effort to get ahead of the game should the drought persist.
In an earlier letter, however, environmental groups The Bay Institute, the Natural Resources Defense Council and the Pacific Coast Federation of Fishermen’s Associations warned that lowering the DO standard — combined with the weakening of other standards earlier this year — could have a “catastrophic effect.”
Reducing flows on the Stanislaus won’t just lower DO, they wrote. It will also warm river temperatures and reduce the quantity and quality of habitat for spawning.
And the impact could be felt downstream of the Stanislaus, on the San Joaquin River and in the south Delta. The San Joaquin already struggles with low DO levels in the Stockton Deep Water Channel; less freshwater contribution from the Stanislaus won’t help, the groups warned. And fish will be particularly vulnerable to any changes in DO, since the San Joaquin is already unusually warm and polluted this drought year.
Lowering DO levels below 7.0 could make fish less capable swimmers, the groups said. Dropping below 6.0 could interrupt their migrations altogether.
Ultimately, delivering even the minimum contractual amounts of water to Stanislaus River farmers was enough to deplete cold water stored behind the dam at New Melones, the environmentalists said.
“Neither Reclamation’s water rights nor the water rights held by other water users on the Stanislaus River entitle those users to further devastate native fish and other public trust resources at teh expense of all current and future Californians,” the groups concluded.
For its part, Stockton East supported the change, arguing in a July 13 letter that the 7.0 standard at Ripon is “contrary to the best available science” since cold-water fish are many miles upstream during the summer. Stockton East didn’t get any of its contracted water from New Melones this year, but every drop held back behind the dam this year is a drop that Stockton East might be able to get next year if the drought eases.
“This change will allow Reclamation maximum flexibility in the use of the very limited water supply,” wrote Stockton East attorney Karna Harrigfeld.
As for all of the other weakened standards, some environmental groups filed an appeal earlier this week while others — including Stockton-based California Sportfishing Protection Alliance — filed a lawsuit. In the latter case, filed at Alameda County Superior Court, CSPA argues that reservoirs for several years have been drawn down more than they’ve been replenished.
In this way, CSPA alleges, the operators of state and federal reservoirs “have refused to provide a margin of safety… to meet the state’s Mediterranean climate and over-subscribed water delivery system.”
Instead, water regulators “bail them out” by relaxing standards, the lawsuit says, while fish species, “hanging on the lip of extinction, pay the price.”