Leaking Willard Bay dam fixed to prevent flooding

WILLARD, Box Elder County — Fast work continuing late into a rainy, cold, windy night prevented what an official calls "significant" flooding, after the Arthur V. Watkins Dam began to leak Monday.

The 40-year-old dam creates Willard Bay between the Great Salt Lake and I-80. About 30 feet to 35 feet high, it is built of rock and earth fill. It stretches for 14.5 miles, surrounding the fresh-water reservoir.

About 2 p.m. Monday, a farmer noticed water between the western section of the dam and a large local cattle feedlot. From 100 gallons to 150 gallons a minute were percolating under the dam's base. It had begun to bore a "pipe" through the structure, with fill material flowing out.

The feedlot and possibly a home could have been in harm's way. Experts doubt the water would have flowed onto the freeway.

The farmer notified the Weber Basin Water Conservancy District, which manages the dam, and the district told the U.S. Bureau of Reclamation. Emergency repairs soon began, following a plan drawn up earlier.

By 4 p.m., dump trucks filled with sand were trundling along the dam. The sand formed a filter, preventing further erosion of the dam's interior. These were followed by loads of gravel from a gravel pit about eight miles away. This packed down the sand, holding it in place.

Tuesday afternoon, a grader plowed slowly along the top of the dam, pushing aside mud and helping to pack down the route.

At the leakage site, a wide slope of sand and gravel stretched from the top of the dam toward the feedlot, where hundreds of cattle ignored the activity. A small flow of clear water trickled from the bottom of the slope, showing it was not carrying material from the dam's interior.

Tage Flint, the conservancy district manager, said that while the district operates the Weber Basin Project, "the title's still held by the Bureau of Reclamation."

Bruce Barrett, manager of the bureau's Provo operations, and Flint were attending a water conference in Provo when word came. They immediately left the meeting and drove to Willard Bay, where they stayed to help with the work.

"We finished at 10:30 last night," said Barrett.

Altogether, 30 dump-truck loads of sand and 40 of gravel were pushed into place. Up to 700 cubic yards of fill were used with between 600 cubic yards and 650 cubic yards in place.