Bank erosion along the Missouri River near Calumet Montana Refining has the potential to cause damage to the river, infrastructure and trail users.

In an effort to prevent that, several area agencies have banded together to apply for a pre-disaster mitigation grant from the Federal Emergency Management Agency.

The group is seeking about $453,000 to stabilize the west bank just upstream from the 9th Street bridge.

Initial design work identified three different but consecutive reaches of the river bank that need stabilization. The bank height varies from seven feet high on the upstream end to 20 feet on the lower end. Stabilization is required to protect public infrastructure in the area that includes a 30-inch diameter sewer main that serves Black Eagle and it’s 1,087 residents, according to the group’s letter of intent for the grant. Calumet also has infrastructure along the bank and the River’s Edge Trail runs along the edge.

If the bank were to erode further, it could cause a break in the sewer main, disrupting service in the area and sewage could spill into the Missouri River.

“if the sewer main sloughs and breaks, we have a real problem,” Tenlee Atchison said.

Atchison is the district administrator for the Cascade Conservation District and said the community learned of the FEMA grant last summer but wasn’t apply to apply due to the short timeline.

The group developing the plan includes the CCD, City of Great Falls, River’s Edge Trail Foundation, Calumet Montana Refining and Northwestern Energy.

The grant funds would allow the group to address the most critical area near the bridge and Atchison said they’d pursue other funding sources to complete the rest of the bank stabilization projects since they’re further from critical infrastructure.

Atchison said the grant could open for applications “any day now” and it’s typically mid- to late August.

As part of the federal grant, the grant applicants have to provide a 25 percent match and the local group is working on identifying the match funds in terms of dollars or in-kind matches, Atchinson said. That match is about $113,000.

Jim Rearden, city public works director, said the city is applying for grants to cover the match and it’s been proposed that any remaining match come from the city sewer fund, River’s Edge Trail Foundation and Calumet, Rearden said.

The state has to be the grant applicant and the city would be the subholder, Atchison said. The application window is short, so the local group has been working to have their application ready to go, she said.

Doug Wicks of the River’s Edge Trail first notified CCD of the failing bank in summer 2014. Since then, the group has been meeting to study the issue and find solutions to the problem. In 2015, CCD received a $75,000 planning grant from the Montana Department of Natural Resources and Conservation and hired WWC Engineering in Helena to provide a preliminary engineering report.

The area near the bridge and gabion baskets “seems to be sloughing pretty bad,” Atchison said.

Gabion baskets are wire cages filled with rocks, concrete or sand and soil for erosion and landscaping purposes. Riprap is often used, but when it comes to erosion control, Atchison said vegetation is more effective.

If the FEMA grant is approved, the bank will be reconstructed by stabilizing the toe of the bank, which is the area that goes into the water and the slope would come up higher at a gentler grade and plants like willows and grasses would be planted.

The trail would be reconstructed but remain along the same path since there’s nowhere to go on the bank.

Once the FEMA grant announcement is out, the group must quickly submit their application and Atchison said they’d be notified around Jan. 1 if they’ve received the grant.

Work could potentially begin next summer and the trail will be inaccessible in that area if it does, Atchison said.

 

 

“This is as long-term of a fix as you can probably get,” Atchison said. “Vegetation is really the best long term solution you can get.”