The West Milton Stormwater Improvement project in New Columbia, Pennsylvania, is a showcase example of a stormwater management challenge solved in a community setting. Funded by the SEDA-COG (SEDA Council of Governments) and executed with MagnumStone retaining walls, this project not only rejuvenated an aging infrastructure but also fortified the community against future potential water-related hazards. The selection of MagnumStone, known for its robustness and environmental efficiency, underscores a commitment to sustainable and effective stormwater management solutions. This short case study delves into the project background, the challenges it aimed to address, the solutions implemented, and the outcomes.
This content is adapted from a more in-depth case study titled, MagnumStone’s Superior Stream Bank Protection.
Background
Nestled in Pennsylvania, New Columbia faced significant stormwater management challenges in 2011, attributed to an outdated and failing infrastructure. The community, surrounded by natural watercourses, needed a solution to protect homes, businesses, and utilities from the risks of flooding and erosion—a solution strong enough to handle unpredictable weather and support the natural environment.
Challenges and Objectives
The primary challenge was the rehabilitation of a stream running through the town, which at the time was beset by a mix of deteriorating walls that inadequately managed the challenges of flooding and erosion. These structures were not equipped to handle the complexities of stormwater management, posing a risk to the community during heavy rainfall and storm surges. The objectives were clear:
- Replace the failing infrastructure with a robust stormwater management system.
- Ensure the new system could effectively manage and convey stormwater, thereby reducing the risks of flooding and erosion.
- Implement a solution that was both environmentally sustainable and economically feasible.
Designing a Streambank Reinforcement Solution for Stormwater Management
Initiated in 2011, the implementation focused on replacing the old stream banks with innovative retaining walls constructed with large hollow core concrete blocks. The design included elaborate underground piping and a graded streambed lined with large stones to:
- Slow down water influx
- Prevent erosion
- Act as a natural filter for stormwater runoff.
Key to the project was the multifaceted functionality of the MagnumStone system, which offered flexibility in design and installation. The ELA Group, engineers of the retaining wall project, selected MagnumStone blocks, which were manufactured locally by York Building Products. ELA Group, already acquainted with MagnumStone’s wall systems from previous projects, opted for these wet-cast concrete blocks as the chosen streambank fortification solution.
Stormwater Channel Construction with MagumStone Retaining Wall Block
According to the project’s specific erosion control plan, engineers buried two layers of the system below the surface. They then packed the area with #57 stone, preparing it for quick water dispersal during floods. Reinforced with geogrid materials, these MagnumStone walls were designed to support the considerable weight and stress from nearby infrastructure.
For added protection and use of space, the project utilized dual-sided blocks at the water’s edge, creating a robust barrier. Fences were then installed atop the walls by anchoring them into MagnumStone’s concrete-filled cores, maximizing the utility of the land.
Community Safety and Stormwater Channels
To safeguard people, animals, and prevent debris accumulation, ELA Group implemented several safety features throughout the waterway. Barrier fencing was erected along extensive stretches of the stream banks to reduce the risk of accidents near the water.
Moreover, ladder rungs were strategically placed in deeper sections as a precaution against the possibility of someone, especially children, being trapped by rising waters. These thoughtful additions underscore ELA Group’s commitment to ensuring the stormwater management system not only manages water effectively but also prioritizes public safety in adverse weather conditions.
Results Achieved
The MagnumStone geogrid retaining wall solution was successfully installed, including segments in community neighborhoods. The stormwater conveyance channels proved their worth shortly after the project was completed when Tropical Storm Lee hit in the fall of 2011. This storm tested the new stormwater management system with over 15 inches of continuous rain, a situation that could have led to significant damage. The MagnumStone wall stormwater channel system held firm, effectively protecting the community from flooding. This storm event was the first to highlight the walls’ capability to handle extreme weather conditions, ensuring the safety and security of New Columbia’s residents.
Today
The West Milton Stormwater Improvement project stands as a beacon of successful stormwater management solution for water conveyance and stream bank fortification in a community setting. Built with MagnumStone retaining wall block, this project illustrates innovative engineering to safeguard communities against flooding from unpredictable storms by fortifying existing stormwater conveyance channels, such as streams, with concrete retaining walls.
For municipalities and communities facing similar stormwater management challenges, the success of the New Columbia project offers valuable insights. It underscores the importance of choosing stormwater solutions that are not only robust and effective in the short term but are structurally, resilient in the face of future challenges.
