By Kate Klimesh,
The project intended to reduce the risk of flooding in the Upper Iowa River Watershed, improve water quality and increase resilience of the watershed to major storm events through community collaboration with landowners.
The wrap-up meeting of the Upper Iowa River Watershed Management Project was held in the Winneshiek County Courthouse Annex Dec. 15, 2022. With little fanfare, the group discussed the 39 projects completed from 2017-22, with Matthew Frana as project director. The project intended to reduce the risk of flooding in the Upper Iowa River Watershed, improve water quality and increase resilience of the watershed to major storm events through community collaboration with landowners.
In 2016, the State of Iowa secured a $96.7 million Federal FEMA Disaster Resilience Grant issued through Housing and Urban Development (HUD) to address flooding issues throughout the state. The grant proposal “The Iowa Watershed Approach (IWA)” is a vision for Iowa’s future that voluntarily engages stakeholders throughout the watershed to achieve common goals, while moving toward a more resilient state.
The grant was divided among nine Watershed Management Authorities, with the UIRWMA receiving $5.7 million, with $4.2 million used for planning and construction efforts toward flood mitigation along the Upper Iowa River. This collaboration included members from Howard County, Allamakee County, Winneshiek County and their Soil and Water Districts and the City of Lime Springs.
UIRWMA worked closely with Upper Iowa
Efforts were focused within six Upper Iowa sub watersheds: Canoe Creek, North Canoe Creek, Ten-Mile Creek, Coon Creek, Community of Nordness and Trout Creek. These priority areas were determined following an assessment on the following qualities: high runoff and localized flooding following rainstorms;
property damage including washed out roadways; landowner willingness to participate. They were then confirmed by Iowa Flood Center modeling as successful candidates for rehabilitation.
Among the work done in the 39 projects, there were 15 grade stabilization structures or ponds constructed, six water and sediment control basins, seven county road projects, eight waterways, two wetlands and one terrace. Sixteen of the projects incorporated utilizing native prairie species into the flood mitigation efforts.
The Canoe Creek and North Canoe Creek sub-watersheds had sandstone bedrock concerns. Some areas featured severe fractures or sinkholes or limited suitable soil to work with, limiting the projects in this sub-watershed. Ten projects treating 1,264 acres were completed.
Also in the Canoe sub-watershed, the South Pine tributary contains the only know source of a strain of native Iowa Brook Trout in the state, which are now being used for breeding to stock other streams. The Webber and Baumler projects were constructed within the south pine sub-watershed and will help contribute to protecting water quality of this special stream.
The Trout Creek and Nordness sub-watersheds was the most suited for water detention projects. While there were still Karst concerns, they were minimal. This watershed saw five of the seven road projects completed. Many of the road projects removed big dips in roadways and ensured adequate water management with adjacent ponds, basins or culverts. Twelve projects treating 2,735 acres were completed.
Several other roads were identified, but those unfunded projects prohibited further work. This watershed empties just above Freeport, and efforts will hopefully prevent the damage done by the likes of the 2016 flood which brought eight inches of rain in less than 24 hours.
The Ten-Mile Creek Watershed provided ideal conditions for wetland-type projects and was the only site to use the sheet piling-style wetland format. Many wetlands were legally drained historically, and have a high potential for future projects. With only three projects in this sub-watershed, it still treated 1,058 acres for water retention and redistribution following heavy rains, curbing erosion and nutrient runoff.
Coon Creek sub-watershed had one project treating 129 acres. Due to the steep terrain, heavy use of flatland for crops and high occurrence of sinkholes, suitable projects were difficult to find.
Of the projects completed, approximately 5,200 acres were impacted by water detention structures. Stream flow reductions can vary per project, but on average the group estimated an 85 percent reduction in streamflow on structures designed to hold back up to a 10 year rain event (4.5 in/24hr) or 25 year rain event (5.6 in/24hr). Around 66 percent reduction in streamflow is expected on structures that hold back a 50 year rain event (6.5 in/24hrs).
Frana worked with several technical staff and engineers to design the unique projects, including the Natural Resource Conservation Service, Upper Iowa Watershed Project Technician, Shive-Hattery Engineering and WHKS Engineering.
Frana noted pros and cons working with both federal and private contractors. “Working with NCRS offered free design services, which were usually simpler and more practical, contractor-friendly designs. They also tend to stick to NCRS standards and specifications. Private engineers can get a high volume of projects designed in a shorter time, and I found they were usually more flexible in unique situations versus the NCRS standards. Many of the road projects didn’t really have the specs for that through NCRS, so it was good to have the private engineers to assist with those.”
The project spent a total of $3,371,521 on the projects, $999,562 on engineering and technician costs to design the projects, $226,226 on road easements and $355,654 on the project coordinator over the life of the multi-year project. With other expenses, the total spent on the project was $4,855, 266.
The Winneshiek County Supervisors budgeted $300,000 toward the project, of which approximately $55,000 was utilized. The remainder of the funds will be returned to the general budget.
At the project wrap-up meeting, Northeast Iowa Resource Conservation and Development representative Ross Evelsizer noted that many of the Watershed Management Authorities would be losing their directors as a central point of contact and encouraged counties to consider continuing the position to maintain a central point of contact for project maintenance and future opportunities. They also outlined a potential job description for an UIRWMA coordinator. Frana will continue as Project Coordinator for the Turkey River Watershed.
Find the full report on the Watershed Project on the Driftless Journal website or visit www.upperiowariver.org for more information.