Tuesday, March 4, 2014

storm waters captured but dams not near full

Stormwater behind Morris Dam: 7:15 a.m. March 4 2014

By Guy McCarthy

Update 4:23 p.m. Whatever volume estimates the Department of Public Works comes up with for storm water capture since the recent rains, the levels behind Morris Dam and San Gabriel Dam today look the same or lower than Feb. 11 and Feb. 18, when Los Angeles Times photographer Don Bartletti visited.

Click here to view and see if you can spot a difference. What do you think?

Posted 1:48 p.m. Low clouds loomed over Glendora and Azusa early Tuesday, but the rising sun broke through fog further up in the mountains, glinting off stormwater captured behind dams on the San Gabriel River.

Some locations in the San Gabriel Mountains received more than 10 inches of rain during the recent storms, according to the National Weather Service. But the reservoirs above Azusa were not nearly full.

Instruments at Morris Dam north of Azusa on the San Gabriel River, measured 5.19 inches between Wednesday evening and early Monday, and further up the drainage San Gabriel Dam got 8.50 inches, according to a precipitation summary published at 5 a.m. March 3.

Further east in the San Bernardino Mountains, 11.11 inches of rain fell on Yucaipa Ridge from Thursday to Sunday, according to the Weather Service.

Whether the recent rains had significant impact on the current drought is open to speculation and debate. Regardless of the drought, something is better than nothing.

"Before these recent rains all the county's reservoirs were at minimum pool," Kerjon Lee of the L. A. County Department of Public Works said Tuesday in a phone interview. "That means in the cases of Morris and the others there was just enough water to protect  the valves for controlled release of water."

Stormwater behind Morris Dam looked a steely gray-green in the morning sun. Further up canyon behind San Gabriel Dam mud, debris and sediment were evident in the brown mix.

Behind San Gabriel Dam: 8:40 a.m. March 4 2014

Erosion and accelerated sedimentation are a concern for the Department of Public Works, which has been responsible for the Morris and San Gabriel dams and reservoirs since 1995. They were both built in the 1930s for dual purposes: flood control and water conservation.

The Morris Fire in August 2009 scorched watersheds that drained into portions of both reservoirs, but the Colby Fire burn above Glendora and Azusa does not appear to impact either reservoir.

Other dams, including Devil's Gate, Pacoima and Tujunga, still require cleaning out from the massive September 2009 Station Fire, Lee said Tuesday.

On Ridge View Drive in Azusa: 9:15 a.m. March 4 2014

Out on the mountain front in Azusa, residents, volunteers and others were at work removing mud from a yard behind a home on Ridge View Drive, near the west edge of the 1,950-acre Colby burn.

K-rail and sandbags remained in place on many residential streets in Glendora, where utility crews and other workers continued storm cleanup.

Photos by Guy McCarthy


No comments: