The ditch that runs along King Avenue East in Billings and drops into the Yellowstone River at Washington Street drains a third of the city's storm water.
"When it rains, it's a lot of water," said city engineer Debi Meling.
So much water that these days the drainage never empties. Already this year, it's been full 289 days. Spring flooding after a winter of record snowfall and early rain prompted Meling's team to find a way to get more storm water to move through the drainage ditch faster.
They discovered two things. The river channel near the city's drain has moved significantly during the past 50 years, bringing water closer to the drain outlet. And they found that when the Yellowstone was in any kind of flood stage, the river water backed up into the drain and the storm water pouring out of the city simply stayed in the ditch.
"There's nowhere for the (storm) water to go when it hits a full river," Meling said. "It took us a long time to figure out the problem because there was water everywhere."
To solve the problem, the city has proposed laying new pipe and moving the drain a half mile downriver, where it will empty into the Yellowstone 10 feet lower than the current drain at Washington Street.
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That new 10-foot drop will help move water out of the drainage ditch quicker and keep water moving so that it no longer sits in the ditch for days or weeks at a time.
Along with the new pipe and drain, crews will install a flood control gate near the current drain at Washington Street to help stop back flows coming in from the river when it's in flood stage, and to better control the water that moves through the ditch.
The city council approved the project at their meeting Monday night.
Crews would work through the winter and the new drain and flood control gate would potentially be in place in time for spring flooding.
To manage the project, the engineering department is using a new method for selecting a contractor that forgoes the bidding process. A recent change in state law allows for government entities to use a qualifications-based selection process on certain projects.
Instead of going out to bids on a project and then taking the lowest bidder, the department instead works with a trusted contractor, both sides agreeing to costs based on market prices and then evaluating those costs at every step of the project.
The speed is what appeals to Meling. Going out to bid, waiting for the offers to come in and then selecting a contractor would have put the project completion date sometime in late July. Working with a contractor at the outset means the project can start as soon as it's approved by city council.