The construction of wetland systems reduced peak runoff by up to 25 percent.
CREP Sites in Dallas
Boone, and Emmet Counties, Iowa Department of Agriculture and Land Stewardship (IDALS)
Boone, Dallas, and Emmet County CREP sites needed nitrate and herbicide removal to reduce hypoxia in the Gulf of Mexico. Bolton & Menk designed wetlands to correct these problems. The 1,500-acre Boone site is on a tributary to Squaw Creek; the 2,500-acre Dallas site is on a tributary to Beaver Creek; and the 500-acre Emmet County site drains directly to the Des Moines River. In addition to water quality improvements, peak runoff from these systems was reduced by up to 25 percent with the construction of these wetland systems. The design consists of berm construction across the drainage basin valley with a permanent pool designed for a shallow wetland area with various structures to slow the release while conveying storm events in the basins.