Study: Levees Meant For Flood Control Can Instead Increase Risk
MANTECA (CBS13) — UC Davis researchers say in some cases levees can do more harm than good when it comes to flooding.
Dale Kilburn appreciates dry ground. He lived through one of the worst floods in Central Valley history in 1997. But without flood insurance, he lost furniture in his and his mother's home.
"When I got done, I had to buy two refrigerators, two VCRs, two microwaves, two of everything," he said.
During that year, there were six levee breaks near Manteca on the San Joaquin River.
UC Davis researchers recently studied big levees on the Mississippi River and say some communities are better off without levees. They say the levees will redistribute water, leaving certain areas with higher water levels than normal. When those levees fail, the flooding is that much more catastrophic.
Manteca only manages one levee, while the rest are managed by a reclamation district.
"In my opinion, levees do not create more vulnerability. It's set up as a protection system," said city engineer Kevin Jorgensen.
UC Davis geologist Nick Pincher says cities should have levees only to protect existing infrastructure, but he says new construction developments should be carefully scrutinized before building a levee.
The study says homes have a greater flood risk with levees, but farmland benefits by keeping the land dry year round for crops, and also help recharge groundwater.
"They put so much rock in there, that place is never going to break again, but there's other weak spots," Kilburn said.
Maintaining the current levees is critical, and the study says we need to think harder before building more.