USHERS CREEK RESTORATION
Ushers Creek drains approximately 250 acres of upstream land through the Heritage Green neighborhood in Hiawatha, IA. The creek filled with sediment and debris over the years, causing periodic flooding in the neighborhood.
To remedy this, Hall & Hall Engineers (HHE) was hired to used topographic survey and historical aerial photos to restore 1,650 linear feet of the creek in its pre-development location. HHE also obtained permanent drainage easements from landowners for future City maintenance.
Located in a wetland, a wetland delineation was required and completed and a US Army Corps of Engineers permit was obtained. The Corps would not allow any fill, including riprap, to be placed within the project limits and therefore, in lieu of traditional hard-armored erosion control, the design took a “soft” approach by considering channel curvature, side slopes, width and turf reinforcing materials to reduce the risk of recurring erosion. The surface was restored with native seeding. Public coordination was ongoing throughout design and construction, including individual and group meetings, and incorporating public input into the project whenever possible.
SEMINOLE RIVER BANK ARMORING
CEDAR RAPIDS, IA
Hall & Hall Engineers (HHE) designed approximately 1600-LF of embankment repairs along the Cedar River stabilizing heavily eroded areas threatening the City of Cedar Rapids raw water supply.
Several areas along the Cedar River near Horizontal Collector Well #4 and Seminole Well #2 were eroding away and close to compromising the integrity of both city access road servicing those two wells and the raw water line connecting them to the City’s water supply system. HHE engineered erosion control measures reducing the risk of further erosion in those two areas. Permits, archeological surveys, and potential wetland mitigation measures required close communication with the Iowa Department of Natural Resources. Additional communication was required to coordinate access to the construction site through the Seminole Valley Park and Museum entrance road.