What is sad about this work being planned in the Parkway—which will result in serious damage—is that it will only improve Sacramento’s flood protection to the 200 year flood level, below that of New Orleans prior to Katrina, so not really so good; whereas building the Auburn Dam would protect Sacramento at the 400 year level and probably not even require the work in the Parkway.
An excerpt from the Sacramento Bee article about this.
March 26–Years of rumbling dump trucks and backhoes placing 2.75 million tons of rock “armor” along nearly a dozen miles of riverbank is an unpleasant thought for many who bike, jog, fish, bird-watch, golf, boat and swim along the lower American River Parkway.
But to demonstrate why officials currently are planning for some version of that scenario, Rick Johnson, the executive director of the Sacramento Area Flood Control Agency, points to a striking aerial photo taken after one of the worst deluges ever recorded in this region.
The photo was snapped in February 1986 after an extraordinary Pineapple Express storm filled reservoirs and rivers and pushed Sacramento’s flood infrastructure to its limits. The image shows an area near where the Capital City Freeway crosses the American River; it looks as if several giant bites had been taken out of the massive levee there.
Just on the other side of the levee sits the River Park neighborhood. If the rushing river — which at one point was surging with more than a million gallons per second — had eaten away just a few more feet of the barrier, Sacramento would have been awash in floodwater that would have rivaled what swamped New Orleans during Hurricane Katrina. Tens of thousands of homes could have been flooded.
But it wasn’t until the American River receded that anyone knew how close the city had come to disaster.
“The scary part is you couldn’t see (the damage to the levee). It was all underwater,” Johnson said. “We didn’t even know that was happening until after the water came down. They should have evacuated, quite frankly.”
Prompted by recent changes in state and federal flood control policy — largely in reaction to Katrina — local officials and the U.S. Army Corps of Engineers are in the initial phases of planning a $375 million project that would add a layer of rocky erosion protection along up to 11 miles of the lower American River.
The levees under consideration stretch along segments of the American River, starting where it meets the Sacramento River near downtown and ending upstream near the Butterfield neighborhood, which is about 4 miles east of the Watt Avenue bridge.
The project has presented flood control officials with a major challenge: How do they balance the need to armor the levees against erosion while at the same time protecting — or restoring after construction — the stream-side riparian habitat, as well as the trails and river access that make the lower American River Parkway a local treasure?
Such discussions are underway, and flood control officials encourage those interested in the future of the parkway to attend regular riverbank-protection meetings hosted by the flood control agency.
Crews won’t break ground on the project, which still requires both congressional and local funding, for at least three years. Sacramento voters soon will be asked to approve a ballot measure to help fund the work along with several other local flood control upgrades.
Johnson said everyone involved in the planning — from engineers to local environmentalists — would like to avoid miles of rock stacked along the sides of the American River, similar to what’s been done to areas bordering the Sacramento River. Not only is the armor unsightly, it makes the banks of the river inaccessible.
“That’s what we do not ever want to see again,” Johnson said. “This is an opportunity to avoid that.”
Engineers have improved methods for placing and concealing protective rocks. Even so, some park users and neighbors are worried. While few deny that some level of erosion-control armoring is necessary, some are alarmed that the initial plans outlined in environmental-reviews and planning documents portend years of disruption to park users — and potentially substantial environmental harms….
Discussions about the future of the lower American River Parkway comes at a critical time for erosion-control funding.
In the coming weeks, local flood officials plan to send out ballots that ask Sacramento property owners to pay for the costs of not just the American River work, but also several other flood-control upgrades across the region. The flood control agency must comply with Proposition 218, a state law governing special-purpose taxes. This requires landowners to vote in an election by mail.
Additional seepage-control work is planned for levees along the Sacramento River from downtown south to Freeport, and in North Sacramento, along several miles of Arcade Creek and the Natomas East Main Drainage Canal. Some of the levees also need to be raised to contain deeper floodwater. The plan includes doubling the size of the Sacramento Weir, located along the Sacramento River near the Interstate 80 overpass, to divert more floodwater into the Yolo Bypass.
Flood control officials also will perform similar erosion protection along up to 10 miles of levees lining the Sacramento River. Most of that work will be south of the Pioneer Memorial Bridge on Highway 50.
In total, those projects will cost about $1.5 billion. When completed, they will satisfy a 2007 state law that requires all urban areas to achieve 200-year flood protection by 2025.