Drone captures extent of flooding in the Yolo Bypass and Fremont weirs
The Sacramento River, by far the state’s most important waterway, has been running high, fast and dirty in recent days.
Upstream reservoirs on the Sacramento and its two major tributaries, the American and Feather rivers, have been increasing releases to make room for water from melting snow later in the spring.
California’s drought may not be officially over, but what’s been happening during the winter, thanks to the El Niño ocean phenomena, is a far cry from years of severe water shortages that Californians have been enduring.
Some authorities have criticized state water managers for continuing mandatory cutbacks in water use while reservoirs are releasing so much to run to the ocean. The more important issue, however, is that the heavy flows on the Sacramento and other rivers graphically demonstrate how negligent the state has been – for decades – by not building more storage.
The Sacramento River’s recent heavy flows, if captured by additional reservoir space or other storage, would be an invaluable hedge against the possibility, even probability, that we will see more droughts.
Late last week, the river was running at 80,000 cubic feet a second past Sacramento. Each cubic foot contains 7.5 gallons of water, so every second, 600,000 gallons of water were rushing by. That’s nearly 2 acre-feet, which is how large amounts of water are measured – an acre-foot being 1 acre filled to a depth of 1 foot.
Lake Shasta, at the headwaters of the Sacramento, can hold 4.6 million acre-feet when full, while Lake Oroville, on the Feather, is rated at 3.5 million acre-feet, and Folsom Lake, on the American, can contain nearly 1 million acre-feet.
To illustrate the volumes involved, at 80,000 cubic feet a second, the Sacramento’s flow last week could fill a Folsom-sized reservoir in about six days, or a Shasta-sized reservoir in a month.
More pertinently, it could fill Sites, an off-stream reservoir long proposed for the west side of the upper Sacramento Valley, in about 10 days.
We are fortunate that so much of this year’s precipitation fell in the form of snow, because the snowpack is, in effect, a natural reservoir that releases water slowly. But if global warming is as real as Gov. Jerry Brown and others contend it is, future precipitation from an El Niño would be more likely rain, rather than snow, and we could see both severe flooding and severe water shortages if we are not prepared to capture it as it falls.
We badly need more storage capacity, whether it’s in the form of reservoirs or in the form of large sinking basins in which excess flows could percolate into underground aquifers to be tapped later via wells when needed.
The recently approved state water bond issue contains $2.7 billion for storage, but “stakeholders” have been wrangling over what kind of storage, if any, it should be.
The form of the storage is much less important than its capacity. California had a very severe drought during Brown’s first governorship in the 1970s and that should have been the wake-up call. We now have had another. It’s time to quit talking about it and do something about it.