The Scott Avenue construction project involves modifications to the existing dam underneath the Scott Avenue bridge, construction of in-river recreational features and improvements for fish habitat, improvements along the south bank to allow access to the river, and rough grading of the south bank to prepare for a future uplands project that will construct walls, trails, and other outdoor amenities. Watch a live feed of the site here.
In 2019, the project was awarded a $25 million BUILD grant from the U.S. Department of Transportation. As the project is federally funded, the project was required to meet the documentation and notification requirements of the National Environmental Policy Act (NEPA). The project was classified as a Countersigned Categorical Exclusion. Because this stage of the project development happened during the beginning of the Covid-19 pandemic, public comment was officially obtained during the NEPA process through the use of an on-line meeting site. The site was live from May 4, 2020 through June 3, 2020. The availability of the site was published in the Des Moines Register and emailed out to local governments and other public groups who may have interest in the project. In addition to the public website, public meetings were held during the original project feasibility study prior to 2020 and there were public presentations to numerous City Boards and Commissions including the Parks and Recreation Board, Planning and Zoning Commission, Zoning Board of Adjustment (including an additional neighborhood meeting that was necessary for this process) Urban Design and Review Board, Access Advisory Board, Des Moines City Council, and the Des Moines Area Metropolitan Planning Organization. The project received permits from the U.S. Army Corps of Engineers, Iowa Department of Natural Resources, and City of Des Moines prior to construction. The Individual permit through the Corps of Engineers also had a 30-day public comment period.
Design and permitting for the project happened throughout 2020 and 2021. The project was initially bid in December 2021 and March 2022, but due to inflated construction prices the bids could not be awarded. The project was repackaged and in November 2022 the Scott Avenue project was awarded to a joint venture of United Contractors, Inc. of Johnston, Iowa and Reilly Construction of Ossian, Iowa. The total contract cost is nearly $41 million. The contracting authority for the project is the Des Moines Area Metropolitan Planning Organization. Construction of the project is being overseen by Polk County Public Works through an agreement with the MPO. Construction of the project will not be complete until 2026.
Construction of the project began in February 2023. To begin, it was necessary to remove 2.8 acres of trees along the south bank of the Des Moines River. The tree removal was necessary to be able to grade the banks to provide access to the river along the entire project length and meet the requirements of the City’s floodplain development ordinance. No trees were removed that were not necessary to accommodate the project. There were no eagles nests within the trees that were cleared for the project. The trees were required to be removed by March 31st to avoid impacts to threatened and endangered species. Nearly 15 acres of wooded area will remain between E. 1st Street and SE 6th Street.
The Iowa DNR has approved the contractor’s dewatering and emergency action plans to allow work in the river. River levels have been very high the last two weeks. They have now peaked and are projected to come down slowly through the end of the month. The contractor has been working on removing debris on the south bank and will continue grading the south bank at the east end of the project downstream of the recreational drops. Some of the first cofferdams they build in the river will be for this work. The City’s Phase C Levee contractor continues work on the north bank. They are currently stripping topsoil in preparation for importing the clay embankment material.
The contractor continues to haul rock and boulders to the stockpile site and has now submitted a draft dewatering plan today. Additionally, they have removed the railroad bridge abutment on the south bank of the river and has equipment in place to begin grading the bank. The City of Des Moines’ Phase C Levee contractor continues work on the north bank of the river. They are working to replace rip rap along the north bank, installing a seepage relief trench on the land side of the levee, and are starting to import fill for the levee raise.
The contractor has now hauled 10,000 tons of rip rap and over 1,200 tons of boulders to the stockpile site. River levels continue to decrease. The City’s Phase C levee contractor is working on abandoning an existing gatewell and installing a seepage relief trench between SE 6th Street and Scott Avenue on the north side of the levee. ICON’s contractor is working with its engineer on its dewatering and temporary shoring plan. These plans are necessary to meet with the DNR and obtain the necessary permits for their temporary cofferdams and causeways within the river. Once these are submitted and approved, the contractor plans to begin the dam modifications.
Mulch piles were removed from the site last week. The City of Des Moines’ Phase C levee contractor has also completed its tree clearing and has left the site. The river levels have dropped approximately 7’ since the peak on March 1 and are approximately 6’ above the low levels when the project began. The contractor has been hauling Class E Rip Rap to the stockpile site located on the City’s property east of the Harriet Street site. The contractor has hauled nearly 1,500 tons of Class E rip rap to the site. Nearly 20,000 tons is needed for the project. This week the contractor started hauling boulders to the stockpile site. The boulders are coming from Redwood Falls, Minnesota. The contractor plans to haul approximately 90 tons per day. Approximately 7,000 tons are needed for the project. The contractor is working to set up the field offices on a vacant lot at 417 Scott Avenue just north of the project.
Tree clearing is now complete and the contractor is working on clearing the site. The City of Des Moines’ Phase C levee contractor is also clearing trees along the Carl Voss Trail on the south side of the river. That contractor currently has the trail closed for removals. Once the City’s levee contractor is done with clearing, the trail will be reopened. The intent is for the trail on the south side to remain open until the City needs to close it again to construct the levee on the south side of the river. The contractor plans to begin removing the south abutment of the old railroad bridge that used to cross the river. Then they will build a small causeway to get into the river to remove three pier footings from the old bridge. The design team has reviewed the rock suppliers the contractor has proposed for the project. The contractor is completing testing on the sources to verify compliance with the specifications. Once approved, the contractor will begin hauling rock to a nearby staging area.
Construction for the first of ICON’s downtown sites is set to begin this spring, requiring tree felling in a three-acre area along the south bank of the Des Moines River. The historic dam beneath the Scott Avenue bridge is being mostly unchanged by the project with only minor modifications to make it safer, allow paddling access, and improve the fish passage. The overall project is expected to take 3 years and be completed in 2025. Approximately 150 trees will be impacted by the project; however, these will be mitigated according to city ordinance. A combination of tree planting and contributions to the City of Des Moines’ Tree Mitigation Fund will be used to offset the loss of trees at the Scott Avenue site. ICON’s construction has been planned using the highest levels of conservation standards including scheduling fells in a way that avoids potentially impacting the habitats of threatened bat species; ensuring that no bald eagle nests are disturbed and consulting the U.S. Fish and Wildlife Service for methodology and approach; designing new features in partnership with the DNR to ensure for optimal fish passageways and habitats.
Fall 2023: Harriett Street Site Letting
Spring 2024: Scott Avenue Site North Half In-River Work Complete
Fall 2024: Scott Avenue Site Uplands Letting
Summer 2025: Scott Avenue Site In-River Work Complete
Fall 2025: Harriet Street Site Complete
Summer 2026: Scott Avenue Site Uplands Complete
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