A Bit More Detail

Assorted Personal Notations, Essays, and Other Jottings

[LINK] “California Floods Its Fields to Keep Its Cities From Flooding”

Wired‘s Nick Stockton reports from Claifornia in the time of flooding, looking at how its water management authorities are preventing the state capital from getting overwhelmed by water so soon after the devastation of drought.

To see how close California is to being drowned by its recent winter storms, just look to the small crowd of spectators and TV newscasters gathered yesterday on the northwest side of the state capital hoping to watch state water managers open the gates of the Sacramento Weir. The weir, something between a dam and a levee, lets dangerously high water spill over its top into a long, narrow, floodplain filled with rice paddies, grain fields, and other row crops.

Californians pay attention to the weir for three reasons. One: People here are obsessed with water. Two: The thing hasn’t been opened in a decade. Three: Opening the 100-year old piece of infrastructure is a spectacle, requiring a person wielding a long, hooked pole to manually unlatch each of its 48 wooden floodgates. The crowd slept through that spectacle; state workers opened the weir in the dark, early this morning. They can still catch the sight of water thundering over the weir and into the Yolo Bypass, flooding the plain to protect the city of Sacramento.

From 1850 on, Sacramento has flooded numerous times. This was why, in 1916, the city built the Sacramento Weir to protect itself. In the following decades, the state added five more upstream weirs, and several additional spillways. Besides the Sacramento Weir, all of these are automatic failsafes: If the river reaches a certain height, it spills over a weir into the adjoining bypass.

But because the Sacramento Weir’s gates must be manually opened, they must be manually closed, too. And that cannot be done until the water recedes below the weir gate levels. “Once you open them, you’re making a decision that you’re going to stick with,” says Michael Anderson, state climatologist for the California Department of Water Resources. And when that decision happens, Yolo Bypass becomes an inland sea. Birds flock in, and fish swim below.

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Written by Randy McDonald

January 11, 2017 at 5:30 pm

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