The main San Joaquin River channel is starting to show more sand than water these days.
Nowhere is that clearer than just around the bend from Vernalis.
It is where the Stanislaus River joins up with the San Joaquin River of which a 150-mile stretch from below Friant Dam to the confluence with the Merced River was brought back from the dead in 2016.
The view from the Airport Way bridge does not look promising for the threatened Chinook salmon whose future depends on migrating juvenile salmon seeking to travel from the Stanislaus River to the Pacific Ocean.
On Monday the United States Geological Survey monitor at Vernalis measured water flow at 927 cubic feet per second. That is the rough equivalent of 927 basketballs filed with water passing a point during as a second.
The median flow for April 6 based on 92 years of water records is 2,660 cfs or almost triple its current flow. It’s a far cry from 1961 when it was mere dribble of 176 cfs or 1958 when it was a rip-roaring 39,000 cfs. That was before New Melones Reservoir was completed in 1982 to replace the original Melones Dam built in 1926 by the South San Joaquin Irrigation District and Oakdale Irrigation District.
The flow at Vernalis needs to average 3,140 cfs between April 15 and May 15. In non-dry water years if releases are not already at that level, what is called a “spring pulse flow” will occur.
The ramped up releases help move the juvenile salmon down the river and into the Delta. It also helps keep water temperatures cooler. It also gives the threatened juvenile salmon better cover against non-native predators such as striped bass identified in Fishbio research as the main reason the survival rate for migrating juvenile salmon now lingers at around 7 percent as opposed to a pervious 40 to 60 percent range.
The optimum 3,140 cfs flow won’t happen for 30 days this year due to dry hydrology that changes the guidelines for water releases from New Melones.
At the same time Westside farmers will be getting between 5 and 10 percent of the water deliveries from the Bureau. The last time that happened, large swaths of farmland went follow and orchards were left to die off often with 15 to 25 years of fruit production left. While some farmers might be able to switch to wells, that would only exacerbate the growing groundwater crisis.
OID and SSJID — which have invested considerable money into improving salmon habitat on the Stanislaus River and as well as conservation measures aimed at reducing growers’ use of water — have proposed pushing the spring pulse flow from an anticipated 1,400 cfs at Vernalis to almost 3,000 cfs.
They would do so by using the 1988 agreement with the Bureau that recognizes the districts’ shared pre-1914 water rights that is equal to the first 600,000 acre feet of water to flow into New Melones. They are in a position to send as much as 100,000 acre feet of ware during the 30-day period to ramp up fish flows.
The SSJID and OID have also worked with the San Luis & Delta-Mendota Water Authority and State Water Contractors that may get only 5 percent of the water they need from the Bureau this year to purchase the eater by diverting it once it enters the Delta.
In order to do so, SSJID and OID need the blessing of the federal Interior and Commerce departments to make the release as well as allow the transfer to the water once it has helped step up the spring pulse flow.
It’s been 36 days since the request was made. And with nine days left until increased flows are needed to increase the survival changes of migrating juvenile salmon, the federal agencies have not responded to the formal request made by SSJID and OID.
The two districts would use the $250 per acre foot the Westside farmers will pay to further underwrite the cost of fish research and habitat restoration as well as conservation programs within their respective districts.
That is roughly a quarter of the cost that water is now fetching in the spot market in many parts of the San Joaquin Valley.
Making the lack of prompt reaction from the federal government perplexing is the amount of time, energy and money they invested working with environmentalists, the state, and irrigation districts in the San Joaquin Valley to review the 150-mile stretch of the San Joaquin River in an effort to aid fish.
The San Joaquin River Agreement ended 60 consecutive years of the river running dry effectively killing off fish.
Salmon — although not those genetically tied to the spring run — swam up the San Joaquin River past the confluences with the Stanislaus, Tuolumne, and Merced rivers in 2020 for the first time in more than six decades.
The full restoration of the 150-mile segment of the San Joaquin River is expected to cost $1.2 billion when it is completed.
To contact Dennis Wyatt, email dwyatt@mantecabulletin.com