TOWN OF HARTFORD, VT. WORKING
TO RECOVER WITH THE ENVIRONMENT
The Town of Hartford, VT. is winding down the rebuilding of the infrastructure damages sustained from Tropical Storm Irene. One of the damages caused by Irene was to the Quechee Force Main River crossing in the Ottauquechee River. This is the main sewer line within and under the river bed running to the treatment plant from the Village of Quechee. This project took place directly across from the intersection of Quechee Main Street and Old Quechee Road. The project was funded by the National Resources Conservation Services (NRCS) through the direction of the State Conservationist Engineer Rob Allen P.E. This repair was necessary to keep the winter ice and spring flooding debris that moves down river each year from breaking off the outfall pipe coming from the Quechee wastewater treatment plant or the two force main sewer lines going to the wastewater treatment plant. This structure incurred heavy erosion damages around the concrete barrier containing the three pipes, exposing and undermining the infrastructure that supports this critical system. Tropical Storm Irene caused the Ottauquechee River to rise to a 130 year flood level causing a great deal of damage to the Town’s infrastructure (Quechee Covered Bridge, roads in the area, etc.). High water flows moved rocks the size of small cars, changing the river flow to the center of the river rather than evenly across the entire river. This changed the flow by narrowing the channel of the river at this point causing it to flow very fast only in the center of the river. This center cutting caused erosion around the end of the Town’s force main infrastructure and also causing fast rapids making it harder for aquatic life in the river to navigate upstream.
The repairs to the Force Main needed to be done within the waterway in an environmentally correct manner so as to not affect the aquatic life within the river. This meant that the Town of Hartford would first need an engineered design that would withstand the flow of the river without changing the river and harming the environment. The Town contracted DeWolfe Engineering Consultants Inc. to design a sound, safe and environmentally correct project. The Town was required to obtain a permit from the State of Vermont Water Shed Management Division, Rivers Program. Department of Environmental Conservation, River Management Engineer Todd Menees, P.E., P.H. was consulted and he helped engineer all work to be done within the river.
The engineering had to address the issues of repairing an existing concrete structure without contaminating any river water and without restricting the flow of the natural river while repairing the eroded structure. This was not an easy task and would need the expertise of a team of individuals that would guide this project with many environment concerns in mind.
After this repair project was completed, the river needed to go back as close as possible to the original flow pattern, all while addressing the up-stream movements of fish species within the Ottauquechee River.
Stream enhancement work is considered the last line of defense to protect aquatic habitats. Managing erosion makes sense as a part of any project design so that the use intrusive methods to restore habitat will not be necessary. If the erosion is not repaired properly it will allow soil to be washed into the stream, covering and destroying spawning areas for fish. If the river bed is not replaced with the habitat of the aquatic life in mind it will not flow properly and will not create the necessary pools. Sedimentation will then build up in them making these pools too shallow for the fish species of the river. Placing rocks as “Groynes” in an upward crescent shapein the main flow area of the repair area will create a mixing and churning of the river flow helping to oxygenate the water, clearing the pools of sediment. Deep pools are created by the placement of the “Groynes” rocks enhancing the environment for the fish. As the Town, its team partners and the contractor complete this project, we tried to not disturb the aquatic life of the Ottauquechee River
During this project the Town Department Public Works and the contractor, Nott’s Excavating Inc. received help and guidance to protect against any potential environmental impact of this project. By exact placement of gravel wears and these rock Groynes, we were able to restore and replace in-stream channels creating the effective roughness for a safe and healthy fisheries habitat. We would like to thank Nott’s Excavating Inc. supervisor, Reggie Robinson, for the safe, clean and conscientious work during this difficult project. We also thank NRCS, State Conservationist Engineer Rob Allen, P.E., Vermont River Management Engineer Todd Menees, P.E., P.H., Vermont Fisheries Biologist Rich Kirn, Richard DeWolfe, P.E. DeWolfe Engineering Associates Inc., and Trout Unlimited Marty Banak, for their extremely helpful guidance through this repair project and for their care of the environment.
John Knott Jr. CEM.
Hartford, VT. DPW Disaster Repair Project Manager