US Army Corps of Engineers
Rock Island District

District Projects

Upper Mississippi River System Hydraulic Model Update

Published Oct. 28, 2019
Upper Mississippi River Hydraulic Model Graphic

Upper Mississippi River Hydraulic Model Graphic

Contact
Project Management Branch
(309) 794-5208

Location
Upper Mississippi River System, including Illinois Waterway

Description
Developing a standardized and seamless flood risk management hydraulic model for the Upper Mississippi River (UMR) is an essential part of understanding the risks that currently exist to the river communities and is a critical first step for the development of systemic flood risk management strategy. An hydraulic model is a tool that can be used to more accurately evaluate and communicate impacts of floodplain modifications that have already occurred or may be proposed for the future. It can also help provide better predictability and more consistent flood risk management.

Having an hydraulic model for the Upper Mississippi River System has strongly been supported by the five UMR states, federal agencies, local communities and non-governmental organizations. The model could serve as an important catalyst to development of a more collaborative and holistic flood risk management strategy for the region.

The updated Hydrologic Engineering Center River Analysis System (HEC-RAS) hydraulic model incorporates software improvements, navigation dams and the availability of period-of-record inflow data files for various model users. It would replace multiple older models used by state, county and the local community officials and could enhanced flood risk information to assist with community communication and decision making processes regarding land-use and future development in high risk flood areas. The model could also support 408 Levee Modification studies.

Status
Development of the UMR Hydraulic Model Phase I was completed in January 2018 and was a collaborative effort by federal and state agencies, facilitated by USACE Rock Island and St. Louis Districts. It covered 320 river miles from Mississippi River Lock and Dam 19 at Keokuk, Iowa, (River Mile 364) to Thebes, Illinois, (River Mile 44) and used the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) software. The UMR Hydraulic Model Phase I included detailed features, cross sections, and represents the entire floodplain from bluff to bluff.  

For fiscal year 2020, funding in the amount of $575,000 has been approved for Floodplain Management Services (FPMS) for the development of the remainder of the hydraulic models for the Upper Mississippi River. This includes UMR Hydraulic Model Phases II and IV which cover a total of 500 river miles. Phase II stretches from Lock and Dam 10 at Guttenberg, Iowa, (River Mile 615) to Lock and Dam 19 at Keokuk, Iowa, (River Mile 364) and Phase IV would cover the area from Anoka, Minnesota, (River Mile 860) to Lock and Dam 10 at Guttenberg, Iowa, (River Mile 615).

Funding for Phase III of the project, which includes 290 miles of the Illinois Waterway, is anticipated in future budget cycles.

Authority
SI - Special Interest

Summarized Project Costs

Estimated Federal Cost $1,690,000
Estimated Non-federal Cost $0
Estimated Total Project Cost $1,690,000
Allocations Prior to FY 2020 $500,000
FY 2020 Allocation $0
FY 2020 Total Capacity $575,000

 

Major Work Item Current Year
FY 2020:
Expand model development to incorporate Phase II (219 river miles) ($350,000), extending upstream from Lock and Dam 19 at Keokuk, Iowa, to Lock and Dam 11 in Dubuque, Iowa. Phase IV from Dubuque, Iowa, to Minneapolis, Minnesota ($225,000), could also be accelerated with full funding.