Shoring up the levee system along the Green River with 3,500-4,000 pound bags of sand called supersacks, rock-filled cages called HESCO barriers and other flood-control measures is an enormous undertaking.

But as Auburn Public Works Director Dennis Dowdy told the Planning and Community Development Committee on Monday, contractors have finished most of the flood-control work between the Eighth Street bridge and the Reddington levee east of the River Mobile Estates.

This weekend, volunteers with sandbags will complete what remains of this section, from the bridge to a point on the Lone’s Addition levee east of 12th Street Northeast. When the volunteers are done, they will have created a flood wall that matches the elevation of the barrier system all the way up to the Reddington levee.

The City is working against the clock to protect life and property against potential flooding, owing to the compromised holding capacity of the Howard Hanson Dam. The work on the levees will bolster them to withstand a 13,900-cubic feet-of-water-per-second event. Coupled with the completion last week of an interim fix to the dam’s right abutment, the U.S. Army Corps of Engineers last Thursday lowered the odds of flooding from 1-in-3 to 1-in-32.

“Our odds are improving. but it still doesn’t feel good, knowing there’s a 1-in-32 possibility,” Dowdy said. After this weekend, Auburn’s focus will shift to flood-prone areas north of the River Mobile Estates, including the southeast corner of a future subdivision called the Auburn 40, owned by Tacoma-based Tucci and Sons.

The City has agreed to extend its flood wall around the edge of the subdivision while the developer will build the east and north sides of the wall. Tucci and Sons signed the contract with the City on Monday.

Dowdy said that the City will ensure that Tucci meets the same rigorous standards it holds its own contractors to. He said the Corps and King County will inspect the barriers.

“We don’t want this to be a wasted effort, we want it to be successful if we get high waters,” Dowdy said.

Dowdy said the work should be done before Thanksgiving.

From the Auburn 40, a setback levee will extend west across open fields to I Street Northeast, where it will tie into a variety of flood control measures the City will set up north to 272nd Street, including supersacks, sandbags, double-stacked HESCO barriers, berms and Jersey barriers.

Jersey barriers will be placed for rapid deployment along South 277th Street to where the road ties in with Auburn Way North.

“The only material that hasn’t been ordered is for a particular community … just south of Auburn Golf Course, east of Isaac Evans Park… It’s a low-lying community as well. We still have to order materials once the county completes its survey and tells us what they need,” Dowdy said.

Dowdy estimates the work will cost $1.5 million, not including pumps. This estimate does not take into account the costs of ongoing maintenance and repairs. Residents should expect the barrier walls to be up least three to five years or until the Corps of Engineers gives the City the all-clear sign that the dam has been fixed and can function at full capacity.

To volunteer for this weekend’s sandbagging project, call 253-876-1925.