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, guardrail, light poles, and part of the roadway with it. Montague combined the slope stabilization work with its project to reconstruct Dowling Street between Meade and Water Streets in the fall of 2017.
Prein&Newhof performed a geotechnical investigation that included soil borings, site investigations, and survey. Along with field testing and design, P&N helped with acquiring the necessary permits and funding for the water main construction, SESC, and floodplain fill.
P&N provided Montague with three options for stabilizing the side slope:
- Install soil pins, which decrease earth disruption but 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 ft. Restore the slope with deep-rooted native plantings.
- Montague chose the third option: reducing the slope to make it stable. They needed an MDEQ permit because the toe of the slope extended into Buttermilk Creek’s 100-year floodplain. To get this permit, and not increase flooding anywhere, they excavated a shallow depression from the floodplain. 7,900 cyds of fill was used to reconstruction the slope, reinforcing the hill without impacting the 100-year floodplain elevation.
Access to the construction site presented a challenge when dealing with equipment. Permission was granted to demolish an old vacant commercial building at the corner of the project to gain access.
Dowling Street Reconstruction
Along with Dowling Street’s reconstruction and hill slope stabilization, Montague upgraded its downtown with 900 ft. of water main improvements and new streetscapes, sidewalks, and stamped concrete crosswalks. Easements were needed to improve portions of the sidewalk, decorate street lighting was relocated, and trees along the curb line in the downtown business district were moved.
The project was completed on time even with multiple funding sources influencing scheduling. Montague saw remarkable changes in 2017 and is continuing to work on other improvements to its infrastructure. Those projects include updating its water system on several streets, repainting its water tower, installing a new well and well house and constructing another building at its public works facility.