Creeks, culverts, cars, bikes and barrels

Orange and white traffic barrels on Valley View Road near the regional bike trail bridge that were installed in February should be gone in October.

They were there in April and remain on guard in September. The barrels keep east-bound drivers from using Valley View’s right lane from Edenvale Boulevard to about 30 yards beyond the bridge. The sidewalk is also closed.

The grassy and bushy area between the sidewalk and Purgatory Creek has been colonized by backhoes, compressors and work crews. They’ve scraped and moved a lot of soil on both sides of what has been named the Minnesota River Bluffs Regional LRT Trail. The hard hats are repairing an aging culvert for the creek and building a new one next to it.

The trail is managed by the Three Rivers Park District but its 11-mile corridor is owned by the Hennepin County Regional Railroad Authority (HCRRA).

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The county agency purchased the land in the early 1990s for public transit use. Future bike riders and joggers may be sharing the corridor with light rail trains in the future. That’s why “LRT” is part of the trail’s brand.

Beginning in the 1870s, the trail alignment carried freight and passenger trains operated by the Minneapolis & St. Louis and then the Chicago & NorthWestern railroads. The C&NW tracks and ties were removed in the early 1990s.

This April, swaths of scraped-earth on the trail’s 39-foot high embankment were covered with erosion control tarps. From the trail’s crushed-limestone surface, one could look eastward down to Purgatory Creek. It gushed under a golf cart path through twin culverts before zig-zagging through aptly named Bent Creek Golf Course.

In mid-August while snapping photos of the construction site from the trail, the bike-riding reporter was asked by a dog walker what was so interesting.

I enthusiastically shared what I knew about the need for good culverts on Purgatory: that without them, heavy rains could cause the creek to flood and back-up; that the south quarter of the golf course could again flood into a lake, turning elevated tees and greens into islets.

I also talked about the connection between this place and rock legend Prince. A crumbling, graffiti-washed railroad bridge had spanned this once narrow, rural road.

That day, summer buckthorn and foliage and erosion control fences obscured views of the creek from the trail. Only machines could be seen at the bottom of an embankment that had been enlarged with rough clumps of earth scooped up from the base near the creek.

“The railroads built the roadbed a hundred years ago,” explained HCRRA project engineer Kristine Stehly during a virtual interview in late July.

The agency partners with Three Rivers Park District and the City of Minneapolis which operates the former railroad routes for recreational uses. With six trail corridors, the HCRRA has plenty of culverts to maintain. Its ongoing culvert repair program keeps the creeks flowing. This year, Purgatory is its biggest project with a projected cost of $615,000.

Why the high cost?

Restoring a creek culvert that drills through an embankment with a variety of soils, rock and sand is not a simple operation. There are challenges that Stelhy explained using Purgatory as an example.

For starters, a second culvert needed to be built before the original culvert was given a makeover. During this phase, the project had to close the trail a couple of times. It then had to comply with Department of Natural Resources orders. “We had to break off construction this spring,” says Stehly, “because of fish spawning season.”

A temporary dam was constructed a bit upstream to divert the creek through the new culvert so that repair work could proceed inside the old culvert. That culvert will have a stronger but smaller interior but with its new and larger partner, Stehly says, creek flows will return to normal.

The Purgatory project is slated for completion in October 2021 after soil de-compaction and restoration, grass and plant seeding and removal of that long line of traffic control barrels.

Note: The Hennepin County Regional Railroad Authority owns six abandoned railroad corridors that cradle The Minnesota River Bluffs LRT Regional Trail, the Lake Minnetonka LRT Regional Trail and the Midtown Greenway in Minneapolis. For more information click here.