Commentary: Lessons of 1986 floods continue to reverberate
By Dave Kranz
Strong storms that hit California in February 1986 made front-page news, and their impacts continue to affect how Californians think about the state’s water system.
"North state wringing out after record rains," read the top headline in Ag Alert® 30 years ago this week. As farmers, ranchers and residents from communities hit by the storms of 1986 observe the anniversary of the downpour, it's an opportunity to reflect on the forces California water planners must deal with, and the ongoing need to add flexibility to the state's water system.
In early 1986, California was coming off of two previous dry years. By late January, Ag Alert could report that storms had "eased concerns that 1986 would be the third below-normal water supply year."
And during one week in mid-February, the outlook turned from concerns about lingering drought to concerns about the impact of storms that flooded more than 300,000 acres of California farmland.
In our issue of Feb. 24, 1986, Ag Alert reported that the six-day storm siege that "rampaged through Northern California" had left homeowners and farmers with hundreds of millions of dollars in damage and tons of debris to clear.
"Within eight days, the storm reversed the state's water outlook for 1986, from a water-short drought year to a crisis of too much water for the dam and river system to handle," the front-page story reported.
Flooding was particularly damaging in the Sacramento and Napa valleys, but farming regions in many parts of California reported impacts, with losses to tree, vegetable, berry and field crops.
Despite the damage caused in 1986, the strong storms showed the importance of upstream reservoirs such as Shasta, Oroville and Folsom, which act as a first line of defense against flooding in the Central Valley.
In 1986, the population of California stood at about 27 million. Now, we're at more than 38 million and, as our state has grown and it has struggled through four years of drought, we're hearing echoes of 1986 as Californians discuss how to handle storm flows in an El Niño winter.
Water districts have criticized operators of the federal Central Valley Project for releasing water from still-depleted reservoirs in order to make room for potential flood flows. For example, despite the dry spell that hit Northern California in the first two weeks of February, operators of Folsom Lake on the American River increased releases from the lake, the Sacramento Bee reported, "even as the reservoir sat 40 percent empty." According to the Bee, Folsom Lake "spilled enough water to supply the Sacramento region for weeks."
Sacramento-area water districts called for a rethinking of the lake's operating manual, which requires the levels in Folsom to be drawn down when they reach a certain point in mid-February. That manual was revised after the floods of 1986—but hasn't been changed since.
Water users, seeing a lost opportunity to retain more water generated by early-season storms, say those manuals need to be re-examined, because they fail to take advantage of modern forecasting capabilities.
Another aspect of water system operation can become lost in such discussion: the fact that having more places to store water during storm surges would allow operators more flexibility in protecting low-lying areas from floods and in capturing more flows for use during inevitable dry times. Years such as the ones we've just experienced show the continued need for additional water storage. By approving the Proposition 1 water bond in 2014, California voters showed their eagerness to invest in water supply facilities that add flexibility to the water system.
A key change since the floods of 1986 occurred six years later, when Congress passed the Central Valley Project Improvement Act, which combined with the federal Endangered Species Act to change the way CVP reservoirs operate. As reservoir managers have placed more emphasis on benefiting protected fish, additional demands have been placed on the system, further highlighting the need to capture surplus water flows when they're available.
Californians are also paying more attention to groundwater recharge, for example by channeling water onto farmland in pilot projects aimed at replenishing underground aquifers. Drawing water off rivers and streams in times of high flows can benefit both flood control and water supply. Farm Bureau and other organizations are looking for any impediments to such beneficial reoperation of the system, to make sure such impediments are removed, so we can add enhanced groundwater recharge as we add new surface storage.
Looking back at those six stormy days in 1986, and at the 30 years that have followed, shows us the need to heed the lessons Californians should have learned: California precipitation can be extremely variable, and our water system must have the flexibility to move from drought to flood and back again. We must take advantage of improved forecasting and other advancements in technology to operate our system as nimbly as possible—and we must add to our water storage capabilities to help us weather both drought and flood.
(Dave Kranz is manager of the California Farm Bureau Federation Communications/News Division and editor of Ag Alert. He may be contacted at firstname.lastname@example.org.)
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