A degraded and excessively incised storm water channel was redesigned using natural, native materials to raise the channel bed and improve the water quality flowing into a stormwater facility.
The channel, located in Baltimore County, serves as a water inflow channel for a stormwater facility at the bottom of the channel. Over time, the channel had become deeply incised and eroded which degraded the quality of the water flowing into the facility.
Working with the Baltimore County Department of Environmental Protection and Sustainability, Ecotone implemented an experimental low-impact approach to raise the channel bed and increase water quality. Log sills, which are logs stacked upon one another, were installed sequentially along the channel. The log sills reduce the speed or velocity of the water flow, allowing sediment to settle behind the structure. This increased aggradation raises the channel bed, reducing the channel incision and water velocity.
The design strategy of this project was low-tech process-based restoration (LTPBR). LTPBR restorations use hand-built structures to promote natural functions and processes, allowing stream systems to restore themselves over time. For this low-impact project, the materials were harvested on-site and placed manually without the use of any heavy equipment during the construction process.
The redesign of this channel has proven highly successful. Current conditions show the channel has risen over two feet, and the continuous addition of more logs will encourage even more aggradation in the future.
- Low-tech process-based restoration
- “Less is More” ecologically sustainable design
- Improved quality of stormwater
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