A problematic road shoulder area in the suburban village of North Barrington, Ill., was in need of repair. Excessive sheet flow runoff down a narrow, hilly section of roadway created concerns about sediment washout into a nearby restored watershed creek. In addition, due to the village’s narrow rights-of-way and lack of shoulders in some areas, road edges were becoming rutted and costing the village money to repeatedly maintain.
The permeable Geopave system was installed to direct storm water into an appropriate bioswale and create a stable driving shoulder to support vehicle loads even during rain events. The paving units were placed along the road edge and filled with a roadbase gravel. The cross-section was thickened to 8 in. deep to allow water flow through the Geopave and stone layer into a larger rock base, then out to a swale.
“The goal was to direct sheet flow off the sloped roadway through the Geopave and stone and into the base layer, where it [would be] captured and then run into a natural filter strip before reaching the creek,” said Nancy Schumm of Schumm Consulting LLC, project consultant for the village. “This mitigated the problem of water flow washing sediment across the roadway, through a neighbor’s driveway or directly into a stream, carrying nonpoint source pollution with it.”
“The system was a good solution for the city because the paver units are designed with a molded-in mesh bottom that keeps infill in place and allows good drainage. The units were cut and staggered to fit around the 20-ft radius curve along the roadway,” said Dan Salsinger, sales representative for Ero-Tex of Elmhurst, Ill., the material supplier that provided onsite support to the road district workers during the installation.