by Matt Weiser for Water Deeply
California Department of Water Resources manually opens 25 gates at the Sacramento Weir, which directs water from the Sacramento River through the Sacramento Bypass Wildlife Area and into the Yolo Bypass, on February 9, 2017. Experts say more floodplains like the Yolo Bypass are needed to help California weather extremes of drought and floods.Florence Low / California Department of Water Resources
IN JUST A few short weeks, Californians have been reminded that drought has an evil twin: flooding.
Droughts in the Golden State often end with floods, as seems to be happening this winter. But the state’s political and economic fortunes always seem to swing between the two, leaving precious little opportunity to explore the terrain where they intersect.
One place that happens is on floodplains. When rivers swell, floodplains absorb the excess flow, protecting cities built along rivers, recharging groundwater and providing vital aquatic habitat – all at the same time. When drought swings back, we can pump out the groundwater to serve farms and neighborhoods.
There are precious few floodplains left in California. Development long ago eliminated all but about 5 percent of the state’s original floodplain wetlands, aided by levee building that forced rivers into narrow channels between fragile levees.
Now a new effort is building to reunite rivers with their floodplains, a movement that could take the sting out of both drought and flooding.
“We’re kind of reimagining the management of groundwater and surface water,” said Graham Fogg, a professor of hydrogeology at University of California, Davis. “The more we look at it, the more optimistic we are that there are ways to do this differently and better.”
A major step in the transition is anticipated later this year, when state officials are expected to approve a new Central Valley Flood Protection Plan. The plan is expected to include a new “conservation strategy” intended to encourage flood safety agencies to incorporate habitat and water supply components in their levee projects.
What this means, in practice, is floodplain restoration. One way of doing that is to expand narrow river channels by moving levees farther apart. These so-called “setback levees” increase holding capacity for floodwaters between levees, and they also create new riparian habitat.
Continue to read in full HERE.
Droughts in the Golden State often end with floods, as seems to be happening this winter. But the state’s political and economic fortunes always seem to swing between the two, leaving precious little opportunity to explore the terrain where they intersect.
One place that happens is on floodplains. When rivers swell, floodplains absorb the excess flow, protecting cities built along rivers, recharging groundwater and providing vital aquatic habitat – all at the same time. When drought swings back, we can pump out the groundwater to serve farms and neighborhoods.
There are precious few floodplains left in California. Development long ago eliminated all but about 5 percent of the state’s original floodplain wetlands, aided by levee building that forced rivers into narrow channels between fragile levees.
Now a new effort is building to reunite rivers with their floodplains, a movement that could take the sting out of both drought and flooding.
“We’re kind of reimagining the management of groundwater and surface water,” said Graham Fogg, a professor of hydrogeology at University of California, Davis. “The more we look at it, the more optimistic we are that there are ways to do this differently and better.”
A major step in the transition is anticipated later this year, when state officials are expected to approve a new Central Valley Flood Protection Plan. The plan is expected to include a new “conservation strategy” intended to encourage flood safety agencies to incorporate habitat and water supply components in their levee projects.
What this means, in practice, is floodplain restoration. One way of doing that is to expand narrow river channels by moving levees farther apart. These so-called “setback levees” increase holding capacity for floodwaters between levees, and they also create new riparian habitat.
Continue to read in full HERE.
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