By Gary Lloyd
TRUSSVILLE — Construction at the Cahaba River enhancement project site in Trussville is “essentially finished,” a stream restoration project expert said last week.
Greg Jennings, a specialist in biological and agricultural engineering, said at a tour of the project’s progress last Tuesday that two-thirds of the construction was complete.
The project, which began Oct. 27, includes correcting and stabilizing erosion and sedimentation issues along a stretch of the Cahaba River from Cherokee Drive to the Civitan Bridge at Civitan Park. North Carolina-based North State Environmental was awarded the project by the city of Trussville with a low bid of $828,299.46 earlier this year.
About 30 people attended last week’s public tour of the project, which began near the Cherokee Drive bridge and ended at the Civitan Bridge. That’s about 3,200 feet of construction. Jennings and civil engineer LBYD’s Curtis Eatman talked about stream structures such as boulder vanes, erosion and sedimentation control practices, invasive plant management and native plant strategies. Jennings said revegetation on the banks of the river will begin in January.
Eve Brantley, of the Alabama Cooperative Extension System, said planting native trees and plants along the banks will lead to various leaves falling on the river and different insects making it home. She said this will create an “intricate and beautiful system.”
The purpose of the project is to improve water quality, habitat and stream stability of the Cahaba River, and provide a demonstration of urban natural channel design stream enhancement and stormwater management.
North State Environmental completed a similar project on Shades Creek for Samford University in 2010-2011.
The scope of work for the project includes:
• Clearing and grubbing of approximately 2.7 acres of vegetation
• Construction of a new channel section with low bank erosion potential by creating bankfull benches and laying back stream banks
• Installation of in-stream structures including boulder cross vanes, log j-hooks and boulder j-hooks. These will aid in bank protection by reducing velocities and scour potential along the banks while increasing velocities in the center of the channel to maintain and enhance sediment transport.
• Installation of biodegradable erosion control matting along the reconstructed banks and newly created benches
• Removal of non-native invasive plant species
Riparian buffer re-vegetation will consist of native species planted in zones moving from edge of water up to bankfull bench and out to the existing park floodplain.
Contact Gary Lloyd at news@trussvilletribune.com and follow him on Twitter @GaryALloyd.