White River forces Sumner to brace for worst-case flooding scenario

With the White River in Sumner inching just below flood levels in mid-January, city officials took action to protect the banks of the river from flooding.

The city’s public works crew installed Hesco bastions — cages lined with cloth and filled with sand — along both banks of the White River south of Stewart Road. The crew began installation on Jan.13 and worked for three days.

The barriers are meant to prevent water from rising by blocking it from reaching the other side, but allowing it to drain downward. HESCO barriers are also used in military fortification and are considered more efficient than sandbags.

“That river is changing so much. We’re trying to be cautious — we don't want to cry wolf, but we want to be ready if something comes,” said Carmen Palmer, communications director for the city of Sumner.

The city determines whether flooding will occur in a river by measuring its rate of flow in cubic feet per second (CFS). When the White River reaches the 5500 CFS range on Auburn’s R Street gauge, the city anticipates flooding.

City officials constantly monitor the White River at R Street Auburn hydrograph, which measures changes in a river’s discharge, on the National Oceanic and Atmospheric Administration (NOAA)’s website. Sumner residents can watch along anytime.

“It’ll tell you what the river is doing at the moment and what (its) best guess is out into the future,” Palmer said. “It’s a really nice resource. That’s what we’re watching so when that gauge hits 5500 (CFS), we know it.”

The White River sees occasional flooding due to Mount Rainier snowmelt and area rainfall.

“It’s combination of all those things happening at once,” Palmer said. “We’re in danger well into the spring because of the snowmelt.”

The public works crew installed 478 feet of the barriers on the river’s left bank and 600 feet on the right bank for a total of 1078 linear feet.

U.S. Rep. Denny Heck, D-Olympia, helped get the ball rolling on the project, involving the Army Corps of Engineers, which own the HESCO barriers and gave technical advice to the crew on installation.

“When people’s homes, jobs, and ability to travel are threatened by flooding, we can avoid disaster by planning and investing in resources to prevent major loss,” Heck said. “That means bringing everyone to the table, including the city, the county and the U.S. Army Corps of Engineers. We will continue to work together to develop common-sense solutions that protect Sumner residents, property and infrastructure.”

The barriers will likely stay on the river for several years as the city works on a long-term solution to the flooding. As part of its budget, a $850,000 White River Restoration project will work in part toward addressing the issue of flooding.

“We always want to be ahead of (the river),” Palmer said. “We watch that gauge very carefully.”

This story was originally published February 1, 2017 at 10:27 AM with the headline "White River forces Sumner to brace for worst-case flooding scenario."