Location
Upper Mississippi River
Description
In recent years, the Upper Mississippi River watershed has experienced more frequent flooding with higher stages, particularly in the last ten years with major floods occurring in 2008, 2010, 2011, 2013, 2014, and 2019. In Quincy, Illinois, alone, four of the top five record crests happened in the last twenty years. In addition to the challenges of increased flooding, the Upper Mississippi River watershed also lacks a regional flood risk management strategy comparable to the Mississippi River and Tributaries project on the Lower Mississippi River. USACE St. Paul, Rock Island and St. Louis Districts, are working collaboratively with the states and local communities to develop a systemic and sustainable flood risk management strategy that would reduce the risks and consequences of flooding.
Background
The Upper Mississippi River watershed is defined as the drainage area above Cairo, Illinois, at the confluence of the Mississippi and Ohio rivers exclusive of the Missouri River Basin and encompasses approximately 185,000 square miles. It includes the states of Minnesota, Wisconsin, Iowa, Illinois, and Missouri and covers approximately 1,200 miles of navigable river on the Upper Mississippi and Illinois rivers. The UMR watershed and associated environments have a rich record of human history spanning more than 12,000 years and is one of the most archeologically and historically significant regions in the country. In modern times, the UMR has assumed a significant role in the development and prosperity of the Midwestern economy and way of life. The river is both a source of prosperity and challenges.
The waters of the UMR create a nationally significant ecosystem and a nationally significant transportation system but also bring flooding. When the levees and reservoirs of the UMR were built, by both federal and non-federal resources, they were not constructed in accordance with any overall systemic strategy or a consistent design basis. These facilities have a wide variety of structural integrity and provide varying levels of flood risk reduction for similar land uses. Most of the structures were federally constructed or improved, and they were planned, designed, and built incrementally rather than systemically, under various authorities resulting in differing levels of risk reduction. Additionally, in accordance with the project authorizations, these structures are operated and maintained by the local sponsor. The average age of the agriculture systems on the Upper Mississippi and Illinois rivers is 75 years old.
The risks remain high due to a lack of regional flood risk management strategy and the Flood of 1993 provided a vivid demonstration of the vulnerabilities from a lack of regional strategy. Forty-seven deaths were attributed to the Flood of 1993 as well as nearly $15 billion of damage. The social disruption was beyond measure, with more than 70,000 homes damaged or destroyed and approximately 74,000 people evacuated. The Corps is seeking to collaboratively work with other Federal agencies, state agencies, local communities, and stakeholders to develop a Regional Flood Risk Management (RFRM) strategy.
A collaborative, integrated, holistic and sustainable flood risk management strategy is needed to protect the public and reduce the flood damages to the Nation. A resilient Upper Mississippi River FRM system will protect lives and property, secure our Nation by reducing risk from disaster and reduce the potential of future Federal, State, and local expenditures.
The first step in developing a regional flood risk management strategy for the UMR was to develop a hydraulic model to understand and evaluate the impacts of levee and floodplain alterations. The hydraulic model is a key "tool" and is a shared model used by Federal and states agencies to replace multiple existing models currently used to manage the floodplains.
The first phase of hydraulic model development started in FY16 with a $500,000 reprogramming, which allowed the development of a hydraulic model for a 320-mile segment stretching from Keokuk, Iowa, (River Mile 364) to Thebes, Illinois, (River Mile 44). Phase one modeling work initiated in August 2016 was completed in January 2018. Phase two of modeling was funded for $575,000 in 2020 for a segment from Anoka, Minnesota, to Keokuk, Iowa. Phase two was initiated in October 2019 and completed in September 2020. The final phase of modeling, on the Illinois River portion, was funded for $485,000 in 2021. An additional $120,000 was received in 2022 and the hydraulic model and reporting was completed.
In addition to the hydraulic model, there is a need to incorporate the last 20+ years of flood data and the latest climate guidance to update flow frequencies on the Upper Mississippi River. This updated information will provide better information for managing flood reservoirs, identifying community flood risk in the UMR basin, and improving the MR&T operations.
RFRM is a joint effort of the Rock Island, St. Louis, and St. Paul Districts in collaboration with federal, state and local agencies and stakeholders. It works with available information and integrating with work by others and other programs to the extent possible.
Status
USACE is actively working with partners to address the flood risk management issues on the Upper Mississippi River to reduce the risks and consequences of flood related damages and to improve system resilience. The Upper Mississippi River hydraulic model is complete and is available for public use.
Through FY24, approximately $1,765,000 was provided to advance the flow frequency study. Approximately $2 million is needed to complete the effort.
Additional Information
Authority
SI - Special Interest
Summarized Project Costs
Estimated Federal Cost
|
N/A
|
Estimated Non-Federal Cost
|
N/A
|
Estimated Total Project Cost
|
N/A
|
Allocations Prior to FY 2024
|
$2,265,000
|
FY 2024 Allocation
|
$1,000,000
|
FY 2025 President’s Budget
|
$0
|
FY 2025 Total Capability
|
$1,000,000
|
Major Work Item Current Year
FY 2024: During FY 2024, the District worked solely on the UMR Flow Frequency Study portion of the overall Upper Mississippi River watershed regional flood risk management approach to addressing flood risk in the UMR. The study team will complete Phase I of the UMR Flow Frequency Study.
Major Work Item Next Fiscal Year
FY 2025: If funded, work will advancement of Phase II of the Upper Mississippi River flow frequency study. The Flow Frequency study is identified as a potential $1,000,000 earmark in the DRAFT FY25 Appropriations Bill.