The Town of Brownsburg, IN needed to perform improvements to the heavily traveled Tilden Road. This included widening the pavement, installing sidewalks, and improving the existing storm sewer system.
The surrounding area is fully developed, and the project was directly upstream of a steeply-banked stream. Because of this, water quality and erosion control measures needed to be permanent, attractive, and in as small a footprint as possible. Additionally, the engineer was faced with a deep existing storm sewer invert, with depth from top of casting to invert at approximately 15 feet.
Contech was able to offer a set of solutions to the variety of needs on the project. A Vortechs 7000 was utilized upstream of the 48” storm sewer outlet to provide the necessary water quality treatment. Vortechs is a hydrodynamic separator that traps and retains trash, debris, sediment, and hydrocarbons from stormwater runoff.
Vortechs was chosen because of its shallow depth from invert to structure base - providing cost effectiveness over deeper alternatives - due to the system already being 15’ below grade. It took only a day to set the unit. The ease of installation of the packaged Vortechs treatment unit, coupled with a reduced excavation requirement compared to other alternatives, proved to be an attractive option for Tilden Road.
Engineers at GRW opted to also use Contech hard armor erosion control systems in the downstream outlet – 2,367 SF of Class 40 Armorflex was used to protect the steep embankment, and a stilling basin utilizing A-Jacks was installed to decrease flow velocity in order to prevent erosion of the slope and the receiving stream. Both were chosen because of their permanence compared to traditional erosion control measures, as well as their ability to become vegetated, providing the desired visual and ecological characteristics for this residential community.
“Contech was very attentive and responsive to GRW during the design process," said Dan Cutshaw, Engineer at GWR. "I highly recommend using Contech in these types of applications”
The Armorflex and A-Jacks were installed in about a week, providing time savings and reducing total project cost.