The impact levees have on groundwater recharge

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Strange as it sounds, flood control can be part of the solution to managing California’s droughts. University of California scientists have shown that making more room for floodwaters can improve the state’s groundwater supplies and fisheries.

Removing some levees or rebuilding aging ones some distance away from riverbanks can appreciably replenish aquifers during wet years, providing some relief during droughts.

Strange as it sounds, flood control can be part of the solution to managing California’s droughts. University of California scientists have shown that making more room for floodwaters can improve the state’s groundwater supplies and fisheries.

Removing some levees or rebuilding aging ones some distance away from riverbanks can appreciably replenish aquifers during wet years, providing some relief during droughts.

Researchers at UC Merced and UC Davis found that setting back levees rimming the Cosumnes River south of Sacramento resupplied local groundwater storage even in this fourth year of severe drought.

Just a brief storm in early February added an estimated 100 to 300 acre-feet of water to underground stores, about three times more than the amount of recharge from irrigation.

“California’s ability to weather droughts depends on storing more water underground,” said UC Davis hydrology professor Graham Fogg. “Putting levees back away from rivers rather than just keeping aging ones intact will help replenish groundwater, benefiting communities and farmers.”

The researchers removed levees adjacent to the river that were in risk of being overtopped, but contained floodwaters across a 500-acre floodplain with levees set far back from the river.

Levee image via lis.usace.army.mil.

Read more at ENN Affiliate the ECOreport.