Saturday, March 19, 2011

Sacramento’s Flood Prevention Strategy

Writing as someone who lives in the flood zone, I hope the efforts of those who manage Sacramento’s flood protection tools are successful through this very wet period, as reported in today’s Sacramento Bee; but the over-all strategy has been flawed for some time, as the Sacramento solution has long been raising Shasta and building the Auburn Dam, as we have posted on before.

An excerpt from the Bee article.

“The relentless wet weather has pushed flood concerns to their highest level yet in Northern California this winter, with two dozen major river segments now at "monitor" stage.

“The city of Sacramento early Friday closed a floodgate on Del Paso Boulevard to keep the rising American River from flooding the road. It was the first time any city floodgates have been closed since the wet winter of 2006.

“Spokeswoman Linda Tucker said the city did not expect to close more floodgates, which are designed to keep the American River from backing up into the city when it swells. The gates close gaps in levees that are normally open to traffic.

“The river also flooded Discovery Park and portions of the American River Parkway bike path.

“Increased water releases from a number of area reservoirs also pushed up the Sacramento River. It spilled into the Yolo Bypass and is expected to continue doing so well into next week. Portions of county Road 22 were closed for flooding.

“The Sacramento River also began to flood the backyards of riverfront homes on Garden Highway in Sacramento's Natomas region. Some of those homes, which are built on the water side of the levee, have ground-level structures that flooded.

"There are dozens and dozens of houses that have their garages flooded right now," said Doug Cummings, a Garden Highway resident. "I would say most people are being flooded by about 1-foot depth of water."

“Flood-control officials say they do not expect serious problems with continued rainfall this weekend. But they are keeping a close eye on the weather because most area reservoirs are full after a wet winter, and the ground is deeply saturated.

“Shasta and Oroville reservoirs on Friday boosted their water releases to 35,000 cubic feet per second – the highest levels so far this winter.

“The Feather and Yuba rivers are both projected to reach monitor stage this weekend.

“The Sacramento River will be at monitor stage at a number of locations, and is expected to exceed flood stage slightly at Tehama Bridge near Red Bluff – a low-lying area without levees that is often the first to flood.

“In Sacramento, the Sacramento River at I Street Bridge is projected to reach monitor stage about 2 p.m. Sunday – the highest water at that location since 2006.

“The river also is projected to reach monitor stage at Rio Vista on Sunday. With high winds also expected, this raises concern about erosion danger to levees in the Sacramento-San Joaquin Delta.

"The weekend looks pretty wet, and the reservoirs are basically all flirting with encroachment into their flood-control space," said Jon Ericson, chief of the hydrology branch at the California Department of Water Resources. "Everyone's very concerned about inflows and maintaining that flood-control space."

“Flooding on local and urban streams is a bigger concern over the weekend.”