In this article from today’s Modesto Bee, we see another option, rather than dams, for protecting from flooding; moving people from the floodplain and allowing the rivers to flood as they normally do every once in awhile.
This is the Free the Rivers Movement's approach and is the kind of an idea that works well in un-populated areas, but applied in metro areas including locally, would move a whole lot of folks from their neighborhoods, including yours truly.
Nice thought, (freedom always is) bad idea.
Here is an excerpt.
Set aside land along rivers to prevent flood disasters
By PATRICK KOEPELE
About once or twice every decade, California receives abundant rain and snow, which then runs off the Sierra into Central Valley rivers and streams, where high flows threaten lives and property.
This spring exemplifies this type of wet year. Snowpack is about 180 percent of average in the Sierra, the reservoirs are brimming and the rivers are flowing deep and fast. All of this has raised serious concerns about the stability of our state's levees.
Much has been said in Sacramento about a disaster in the making in the Sacramento-San Joaquin Delta. But the flood risk is found along all of the state's rivers, wherever people have decided to build on flood plains.
One solution proposed by flood managers to avert a disaster is to build new levees and strengthen existing ones. While levees certainly can and do protect lives and property, they do not represent a silver bullet. As observed over the years by the state's flood-plain experts, there are two kinds of levees: those that have failed and those that will. When they do fail, the flooding is even more devastating.
A case in point: In June 2004, a levee on the Jones Tract near Stockton broke, flooding more than 12,000 acres of farmland. Another similar disaster in the delta could interrupt the state's water supply system for months, causing a major disruption to the state's economy of New Orleans proportions or larger.
In the Sacramento area, explosive development in the Natomas Basin, a low flood plain, will place more than 20,000 homes at risk of being flooded. Flood experts had estimated that levees would protect against a "100-year" flood, but the protection afforded by those levees was downgraded after an updated analysis found several areas where the levees have been eroded to a critical point.
