In this story from today’s Bee (Arden Carmichael Community News) we see the collateral damage from flooding that a major new dam in the American River Watershed would stop, and the possible buy-out cost the County is considering, of condos that flood the most often, are cost savings that need to be factored in, along with water meters, when considering how much the new dam would cost.
Woodlake, a lovely apartment and condominium complex just north of Fair Oaks Blvd between Howe and Fulton, floods all the time (1986, 1997, and this year) because the American River is too full from mandated Folsom Dam releases to absorb the run-off from the sloughs that normally drain it.
Here is an excerpt.
"Supervisor Susan Peters toured her district, which includes Arden Arcade, Carmichael and Foothill Farms, with county water officials. The Woodside condominium complex near Howe Avenue and Sierra Boulevard was one of the worst-hit areas.
"Water flooded 62 condominiums, the third time since 1986 that the complex has been soaked by an overflowing, channeled tributary.
"Strong Ranch Slough normally drains into a pond near Cal Expo, then into the American River. However, when water runs high, the slough can overflow its banks into the Woodside complex.
"It's a very complex engineering problem, because Woodside is the lowest ground in that area," Peters said.
"In the case of the condominiums, parts of Woodside were built onto a low spot right beside what was once a creek and later became a concrete drainage ditch called Strong Ranch Slough.
"The slough collects runoff from thousands of acres, including a smaller channel cutting through Woodside itself.
"Before there were condos or even levees in the neighborhood, Strong Ranch meandered south and west, joining Chicken Ranch Slough near where both tumbled into the American River.
"River levees complicated that easy draining into the American. A detention pond was built beside the levees near Cal Expo, and pumps were added so water from the sloughs could be pumped over the levee into the American River.
"Today, when the river is low, temporary gates are removed, and the sloughs follow gravity into the river. When the American River gets so high it would flow out of the gate, into the basin and down toward the apartments and shopping centers lining Howe Avenue, the gate is closed, and the pumps go to work.
"The system fails when there's too much rain for the ditches to carry. It also fails if there's too much water for the pumps to move.
"In 1986, slough overflows swamped 180 Woodside condos, and residents were aided by boat, according to Bee accounts. In the smaller storm of 1997, the count fell to 84."
