The work is expected to bring the dam into safety compliance after the seepage issue was discovered during a 2009 inspection of the dam in the Greensprings area east of
"It's getting out ahead of some perceived seismic event," said
As part of the work,
That drop will not impact
The lake will have to recharge itself on its own next winter, Garnett said.
The drop in peak lake level, which still remains significantly higher than most years this decade, also will not alter the
"We're going to have better water conditions than during the drought, but we won't get a full reservoir at Hyatt," Van Dyke said.
ODFW plans to stock 10,200 legal-sized trout there this spring and 39,000 larger fingerlings in October, he said.
Bureau engineers are putting the finishing touches on the designs this month and plan to hire a contractor for the work, Garnett said.
The work is expected to begin in mid-May and run into mid-November, he said.
The design calls for creating a French drain-like system at the dam's base that will capture and filter seepage as it moves the water away.
The bureau four years ago considered other options, including putting filters in the dam so water would pass through without threatening its structural integrity.
That's how the bureau dealt with seepage problems in the 1960s and 1980s.
Another option that was earlier considered was dropping the reservoir's maximum elevation to a foot below the seepage point along the upper portion of the dam's southeast corner, according to the bureau.
That option would have reduce the lake's 16,200-acre-foot capacity by about 6,000 acre-feet, bureau statistics show.
At over 5,000 feet above sea level, Hyatt's ability to draw on high-elevation snow helps make it TID's ace in the hole during dry years. Also, because of limited canal size and other restrictions at
TID built the original
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