Lewis & Clark County Flood Mitigation Master Plan is getting updated

Posted at 11:09 AM, Feb 12, 2022
and last updated 2022-02-12 13:09:07-05

HELENA — Lewis and Clark County is updating its flood mitigation master plan. The effort comes after better modeling of flood impacts showed the need for improved infrastructure for flood mitigation.

“If you’ve ever been through a flood you know that it is gut-wrenching. It is time and treasure from everyone involved. It's a community effort, huge impact on people. We’re trying to reduce that,” says Dan Karlin, County Engineer with Public Works Administration.

After creating a range of flood-mitigating alternatives, Lewis and Clark County asked for public comment from those in the Flood Mitigation Rural Improvement District (RID). These alternatives would better funnel water flow from Tenmile Creek and Silver Creek in the event of a flood.

Newer models showed the more realistic impacts of flooding in the area. As a result, those in charge decided to reevaluate and change the mitigation plan. Since the original mitigation master plan of 2013, computer programming capacity has gotten even better and the engineers behind this program are able to more accurately understand and model what might happen in the event of a flood. They used this information to formulate better plans for infrastructure to flow water into lowlands and away from damaging homes and property.

“That’s a lesson we learned from the Trap Club process. As I mentioned, the original project, once we modeled it, we realized would have been inadequate and quite honestly would have been throwing money away. By having that model, we're confident that when if we get a 25-year flood, that area is gonna be well protected," explained Karlin. "Whereas prior to modeling that, with that powerful software, we would not have known. We would have been hopeful. But at the same time, after modeling it, we know we would have been grossly undersized on everything we put in, so it was very helpful.”

But there’s still work to do. Engineers have narrowed down the alternatives for the next projects. Those ideas will then be presented to FEMA for funding. Karlin says the best choice will reveal itself as the options get narrowed down through planning.

Karlin added that he was very thankful for the community’s input on the mitigation master plan.