Project Description:

General Mills Plant in Cedar Rapids, Iowa

Hall & Hall Engineers, Inc. partnered with Septagon Construction Company and General Mills to provide civil engineering design services for the new 9.1 acre warehouse facility. Their existing 79 acre parcel is located in SW Cedar Rapids, Iowa. Site design included roadways, semi-staging parking, docking and loading facilities, with storm water management being the major design component. With an extensive system of product conveyance amongst warehousing and distribution, an in-depth circulation analysis was required to ensure facility programs functioned as intended with considerations for future expansion possibilities.


Based over site boundary constraints, the warehouse was sited on an existing tributary drainage-way conveying approximately 525 acres of runoff through the site to Prairie Creek. Storm water management included a detention/retention basin with approximately 2.2 acre surface area. Storm water is released from the basin through two, 4’ x 10’ side by side concrete box culverts, which convey storm water under a portion of the building. Overflow is conveyed through an opening provided in the building approximately 40 feet wide by 5 feet high. The channel relocation and modification required securing a Joint Permit application from the Iowa Department of Natural Resources and the Army Corps of Engineers