High water doesn’t last long on the volatile Nacimiento River
News of reservoirs reaching capacity has been coming in from around Northern and Central California this week but, for the Salinas Valley, water remains a problem.
As of this morning, the San Antonio Reservoir holds a measly 18,875 acre feet of water. That’s just 6% of capacity and more than 4,000 acre feet less than what’s considered to be its “minimum pool.” Since the lake hit its all-time low of 10,254 acre feet at the beginning of the year, El Niño rains have added less than 9,000 acre feet to storage. And there isn’t a lot of rainy season left.
Lake Nacimiento, meanwhile, has risen over 24 feet since January, reaching its highest level since September 2013, yet the 123,060 acre feet now in storage amounts to only 33% of capacity.
This matters because these lakes need to release more than 1,000 acre feet per day in the summer and early fall in order to prevent groundwater pumping in the Salinas Valley from lowering the water table and accelerating seawater intrusion. That hasn’t happened since 2013 and, as a result, groundwater levels have fallen to record lows.
With no rain in the current forecast and the end of the rainy season in sight, it remains questionable whether enough water will be on hand to make the releases this year.
Past El Niños have sometimes resulted in substantial late-season rains. Maybe that will happen again?
Please see this previous post for a detailed explanation of how uncontrolled pumping and periodic droughts contribute to seawater intrusion in the Salinas Valley.
Xasáuan Today 
I’ve been watching those levels as well, and it doesn’t look good. My seasonal creeks – okay, not mine, but the ones that cross Plaskett that I watch – were flowing good last week, and expecting even better tomorrow, BUT they dry up and out quickly after the rains stop. Lake Shasta has done exceptionally well, but Lake San Antonio is dismal. Thanks, as always, for your informative report.
Good article XT but very bad news for the Salinas valley. Looks very probable that San Antonio will not get high enough to do any big releases at all; Nacimiento alone can not release enough water in the summer to keep up with the demand. If the flow can’t make it to the lagoon, only minimum releases from both reservoirs are allowed. Hope for a late shot but it looks unlikely at this point.
Ken Ekelund — “If the flow can’t make it to the lagoon, only minimum releases from both reservoirs are allowed.”
Just curious what the reason for this apparent rule is.
The Biolgical Opinion for the Salnas Valley Water Project (rubber dam in Marina) from NOAA NMFS controls how much water and when it is released. Unless there is enough water to send at least 2 cubic feet per second to the lagoon, the agency must stick with minimum releases for the fish.