A new pair of plastic booms, each about 600 feet long, stands ready to catch Rim fire debris that rain might wash into Don Pedro Reservoir.
The storm that was due to arrive Tuesday night was not forecast to be a major one, but managers are not taking chances when it comes to dead trees and other floating hazards.
The booms were installed at two sites close to where the Tuolumne River enters Don Pedro, said Michelle Reimers, spokeswoman for the Turlock Irrigation District.
If needed, the booms can be pulled across the inlet and would trap debris with their 24-inch-deep screens, she said.
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“We know we’re going to get it,” Reimers said. “It’s just a matter of what rate.”
The booms were installed by the Don Pedro Recreation Agency, which manages boating and other visitor activities at the reservoir. An older boom will be kept on hand to keep debris out of the Moccasin Bay area if needed.
The TID and the Modesto Irrigation District also are monitoring the water quality in the wake of the fire, but they do not expect major problems from silt and other debris. The MID treats water for domestic use along with supplying farmers.
The National Weather Service predicted a 90 percent chance of rain Tuesday night and today in the Rim fire area, which spreads across 257,314 acres in the Stanislaus National Forest and Yosemite National Park. In Modesto, the chance of rain was predicted at 80 percent.
The stormy weather, which could continue into Thursday, would help make up for a slow start to the rainfall year that began July 1. The MID reported that Modesto had just 0.32 inches as of Tuesday afternoon, well short of the historical average by this date.
But the heart of the rainy season, December through March, lies ahead, and the city has a chance of reaching the average season total of 12.19 inches. The past two years have been less than average, after two years of substantial rain.
More important is the central Sierra Nevada snowpack, the main source for the MID, TID and numerous other water suppliers. Runoff projections are not available, but a third dry year could mean irrigation cutbacks ranging from mild to drastic around the San Joaquin Valley.
The Rim fire started Aug. 17 and burned over several weeks. Parts of the burned area have a moderate to severe risk of soil erosion during major storms, federal officials said.
A key concern is washouts on dirt roads in the national forest, which will be needed for salvage logging over the next two years and for replanting of many areas with tree seedlings.