Background/Discussion
The area of East Manawa is very flat with open ditches. There are no storm sewers in this area and the streets are thin asphalt or seal-coated rock roads. During rainfall events, considerable surface ponding occurs due to the poor drainage.
Due to the narrow right-of-way and the high water table in the area, conventional storm sewer construction is not practical in many areas. The use of porous pavement in conjunction with a drainable granular base and shallow subdrain/conveyance system was determined to be the most cost effective means available to improve the area drainage. The rehab program has also included installation of new sanitary sewers utilizing a vacuum system.
Phases I thru XII are complete and included construction of the vacuum sewer pump station, Huron Circle, Aztec Street, Blackhawk Street, Osage Street, Victor Street, East Navajo Street, Pickard Lane, and vacuum sewer along Navajo Street from the pump station to Comanche Street. Phase XIII is currently under construction and includes Mohawk Street from Navajo Street to Comanche Street and Comanche Street from Navajo Street to Mohawk Street. Phase XIII will be complete in the fall of 2025.
The limits for Phase XIV will be determined during the scoping phase for the project.
This project was included in the FY26 CIP with a budget of $1,050,000 in Local Option Sales Tax funds and $450,000 in Sewer funds.
EGA will continue as the project engineer. They were previously selected from the pre-qualified list of engineers because of their successful project history and strong relationship with the Iowa DNR, and subsequently provided engineering services for the previous project phases.