As Dowling Street leaves downtown Montague, it climbs a steep hill. The hill’s foundation is mostly sand, and an old retaining wall and vegetation rooted on its side slope kept it from sliding away. Over the last several years, the hill’s side slope eroded and slumped, threatening to take the sidewalk and part of the roadway with it.
Prein&Newhof performed a geotechnical investigation and provided three options for stabilizing the side slope:
- Install soil pins, which decrease earth disruption, this approach is expensive and doesn’t guarantee longevity.
- Build a steel sheet pile wall at the top of the bank to stabilize the road and sidewalk, but it would not save the side slope.
- Rebuild the hill by adding fill to create a more gradual slope, extending the slope’s toe by about 60 feet. Restore the slope with native seed selected specifically for their deep root structures.
Montague chose the third option: reducing the slope of the hill to make it more stable. The City needed an MDEQ permit because the toe of the slope extended into Buttermilk Creek’s floodplain. To get this permit, and not increase flooding anywhere, the City excavated a shallow depression from the floodplain.
Montague combined the slope stabilization work with its project to reconstruct Dowling Street between Meade and Water Streets in the fall of 2017. Along with Dowling Street’s reconstruction and hill slope stabilization, Montague upgraded its downtown with water main improvements and new streetscapes, sidewalks, and crosswalks. The City saw remarkable changes in 2017 and is continuing to work on other improvements to its infrastructure, including: updating its water system on several streets, repainting its water tower, installing a new well and well house, and constructing an additional building at its public works facility.