May 17, 2010
The Swiney Branch stream channel near the Blue Springs Wastewater Treatment Plant had destabilized in a location that threatened underground utilities critical to wastewater treatment plant operation in late 2010. Long term channel incision had lowered the channel flow line elevation sufficiently that the adjacent stream banks became unstable. A partial stream bank collapse damaged a water line and threatened adjacent sewers and underground electric utilities used to operate the plant.
Terra Technologies performed a geotechnical analysis to determine the degree of future stream bank instability in conjunction with a geomorphic analysis of the channel. The findings were utilized to develop construction documents to address the challenges and prevent damage to existing infrastructure. A gabion wall system was utilized in locations where insufficient space existed to grade a stabile stream bank. Only gravity type walls were considered since overexcavation into the stream bank was not possible without damaging the underground utilities. Additionally, grade control structures were designed for retarding future channel incision. All areas of channel restoration included stabilizing native vegetation to provide additional slope stability and water quality benefits. The design was completed in December of 2010 with construction planned for the summer of 2011. |
