Here we go again. The California State Water Resources Control Board has come out with an updated proposal for unimpaired flows on the San Joaquin River and its tributaries.
Upon first glance, the most-recent rendition isn’t much changed since the board originally floated the proposal in November 2016.
At the heart is leaving an average of 40 percent of water in the river throughout the year for fishery uses in the Sacramento-San Joaquin Delta. That figure could vary between 30 and 50 percent.
You may wonder, “Why all the concern about the San Joaquin River when it’s more than 100 miles south of California’s main rice-growing region?” The water board has proposed similar unimpaired flows for the Sacramento River and its tributaries – it’s just that the process isn’t as far along. And the Sacramento River flows through the heart of the state’s rice region and is an irrigation source for many of those fields.
Friday, the board released what it called a framework for the Sacramento River, calling for an average of 55 percent. It could range between 45 and 65 percent. If the board follows a similar process, it will conduct public hearings to hear comments before releasing a final proposal for the Sacramento River.
With a 40 percent unimpaired flow requirement for the San Joaquin River and its tributaries, average annual February through June in-stream flows would increase by 288,000 acre-feet, according to state figures. Unimpaired flows simply mean water from precipitation or drainage that would flow downstream if there weren’t any dams or diversions.
The effects would be larger at 50 percent of unimpaired flow (485,000 acre-feet) and smaller at 30 percent of unimpaired flow (174,000 acre-feet).
An acre-foot, or about 326,000 gallons, meets the annual water needs of one to two families of four.
The board’s original proposal cited state studies that requiring 60 percent unimpaired flows in the San Joaquin River and 75 percent in the Sacramento River would preserve the natural system to which the fish had evolved.
Impacts on humans, ag
The proposal for the San Joaquin River would reduce water available for human use between 7 and 23 percent, with the lower figure for wet years and the larger figure for drought years, according to state figures.
The potential impacts on the agricultural economy increase as the unimpaired flow percentage increases.
A 40 percent of unimpaired flow requirement is projected to result in an average annual decrease in economic output of $69 million, according to state figures. This represents a 2.5 percent reduction from baseline annual average agricultural economic sector output of $2.6 billion. The impact would be lower at 30 percent ($35 million) and higher at 50 percent ($123 million).
These impacts do not consider the mitigation actions water users would likely use to reduce the economic effects, such as water-use efficiency, conservation, changes in crop type or groundwater recharge projects.
But the Stanislaus County Agriculture Commissioner’s Office estimates those figures are woefully low and instead pegs total losses at $5.6 billion across Stanislaus and Merced counties alone.
Agriculture would be the hardest hit, but industrial and municipal water users also would feel the pinch.
State water board analysis shows that when the new flow objective is implemented, groundwater substitution by local water users could prompt increased groundwater pumping. This comes at a time when water districts will likely have to reduce groundwater pumping to comply with the Sustainable Groundwater Management Act.
To bring its unimpaired proposal to fruition, the board would have to go to court and overturn centuries’ old water rights.
In its initial proposal for the San Joaquin River, the board provided three scenarios, but opted for the middle one. During a series of hearings held throughout the state in late 2016, some speakers representing the fishing industry said 30-50 percent flows were not enough and they favored higher flows of 70-plus percent.
Others, such as the Oakdale Irrigation District and South San Joaquin Irrigation District, countered and said there was no scientific proof that throwing more water after fish would result in improved numbers. Instead, they advocated for carefully timed pulse flows to help move salmon and spawning habitat restoration.
The two irrigation districts, which serve Stanislaus and San Joaquin counties, have already funded several million dollars’ worth of gravel bed restoration projects. Their figures show improved spawning rates.
Several speakers also questioned why the state does nothing to fight striped bass, a non-native species with a voracious appetite for young salmon and steelhead trout. Stripers were introduced into the Delta in the late 1800s for sport fishing.
Then there’s the lingering question of how leaving more water in the rivers will affect Gov. Jerry Brown’s $17 billion Twin Tunnels project. That plan, which he calls the California WaterFix, would involve two 40-foot, 35-mile-long tunnels that would divert water from the Sacramento River south of Sacramento, under the Delta and deposit it into a holding forebay near Tracy. The project is rated at 9,000 cubic feet per second with an average annual yield of 4.9 million acre-feet.
Some of the recent proposals have whittled the two tunnels down to one.
Whether one or two, the math just doesn’t add up. How can you require more water be left in the river and divert 2.4 million to 4.9 million acre-feet more each year? Wouldn’t that leave but a trickle?
Maybe that’s just the new math. One thing for sure – the water wars are just heating up.