There is not enough snowmelt and carryover storage to meet California’s water needs.
Unprecedented declines in inflow forecasts for Oroville and Folsom reservoirs are prompting state water officials to scramble to find ways to make existing water storage stretch for critical needs later in the year, including those for public health and safety, and the environment.
That includes Delta water quality concerns and fish flows for endangered salmon.
The Department of Water Resources and federal Bureau of Reclamation’s filing a temporary urgency change petition with the State Water Resources Control Board on Friday could have a ripple effect on South San Joaquin Irrigation District as well as the cities of Manteca, Lathrop, and Tracy.
That’s because the change petition impacts State Water Project and well as Central Valley Project reservoirs.
The 2.4-million-acre-foot capacity new Melones reservoir on the Stanislaus River is where 600,000-acre feet shared by SSJID and Oakdale Irrigation District is stored is a CVP reservoir.
And while SSJID and OID have pre-1914 legally adjudicated water rights for first 600,000 acre feet of water runoff annually from the Stanislaus River watershed, attempts have been made in previous years to undermine the district’s front-of-the-line status in a bid to meet fish flows and other environmental water needs.
SSJID General Manager Peter Reitkerk indicated the district has concerns and will closely monitor the situation.
At the same time SSJID is awaiting an updated inflow forecast for New Melones. Previous forecasts projected that there would be more than 600,000-acre feet of water runoff this year in the Stanislaus River watershed.
However, if the inflow projection from what has turned out to be an abnormally dry first half of March shows declines in inflow as they have for Oroville and Folsom it could create supply issues for the district.
Reitkerk cautioned everyone to use water wisely given the unfolding situation could have dire consequences as the water year wears one.
If the district needs to change its expectations of receiving 300,000-acre feet of water this year as their share of the OID-SSJID water rights, any cutbacks will be applied equally on a percentage basis between agricultural users and those in the cities of Manteca, Lathrop, and Tracy.
Inflow on Thursday at New Melones was 576 cubic feet per second compared with an outflow of 1,068 cfs. The cfs unit represents the equivalent water volume of one basketball passing a point in any given second. If this were as normal year and reservoirs held more water, the outflow with be exceeded by inflow.
Overall, New Melones is holding 952,614 acre feet or 40 percent of capacity. It is losing water at rate of 1,047 acre feet a day. As such is one of only three of the state’s largest reservoirs not increasing water storage currently. The others are Don Pedro on the Tuolumne River that is dropping 2,707-acre feet a day and Orville that is going down 272-acre feet a day.
The water year outlooked changed drastically a record dry January-February followed December that was a historic high for snowfall and rain. Records go back only to the 1850s.
The Department of Water Resources is also planning to refill the notch in the Emergency Drought Salinity Barrier in the Delta.
Work will begin on April 1 to fill in the notch, with completion by April 15. The barrier reduces the amount of saltwater intrusion into the Delta, allowing for reduced flows from upstream reservoirs to conserve water supply.
To contact Dennis Wyatt, email dwyatt@mantecabulletin.com
