Upper Mississippi River System Hydraulic Model Update

Location

Upper Mississippi River System, including Illinois Waterway

Description

The development of a standardized and seamless flood risk management hydraulic model for the Upper Mississippi River (UMR) is an essential tool to understanding the risks that currently exist to the river communities and is a critical first step for the development of systemic flood risk management (FRM) strategy. The model is a tool to more accurately evaluate and communicate impacts of floodplain modifications that have occurred or may be proposed in the future. This new model will lead to better predictability and more consistent flood risk management. The hydraulic model has been strongly supported by the five states, federal agencies, local communities and non-governmental organizations. In fact, this is one tool a largely divided stakeholder group has collectively agreed upon in more than a decade and could serve as an important catalyst to development of a more collaborative and holistic FRM strategy for the region. A Hydrologic Engineering Center River Analysis System (HEC-RAS) hydraulic model has been completed. This model incorporated software improvements, navigation dams and the availability of period-of-record inflow data files. The updated UMR Hydraulic HEC-RAS model allows for wider use for floodplain management on the UMR system in support of flood risk management and 408 Levee Modification studies. The HEC-RAS model can run unsteady flow hydrographs and provide a base condition to efficiently evaluate proposed changes to the system and subsequent transference of risk. It replaces multiple models currently in use, leading to better and more consistent flood risk management. State, county, and the local community officials now have access to enhanced flood risk information to assist with community communication and decision-making processes regarding land-use and future development in high-risk flood areas. Flood planning tools are critical to proactively reduce hazard risks and invest in hazard response and recovery capacity. The community-based flood planning would mitigate risk to health, safety and property posed by floods in order to protect life, property, the economy and lower the demand for emergency response activities.

Status

Approximately $500,000 of FY16 funding was reprogramed to collaboratively develop, test and review this new hydraulic model for Reach 1 (320 river miles) from Lock and Dam 19 at Keokuk, Iowa (River Mile 364), to Thebes, Illinois (River Mile 44). This increment of the model was completed and widely released for partner and stakeholder use in January 2018.

$575,000 of FY19 funding was reprioritized and received to expand the model development to incorporate priority Reach 2 (219 river miles) ($350,000), extending upstream from Lock and Dam 19 at Keokuk, Iowa (River Mile 364), to Lock and Dam 11 at Dubuque, Iowa (River Mile 583), and Reach 4 Dubuque, Iowa, to Minneapolis, Minnesota ($225,000). Reaches 2 and 4 were completed in September of 2020 and was widely released for partners and stakeholders in October of 2020.

$485,000 out of an estimated $615,000 was provided in FY21 to start the final phase or Reach III of the model. This reach of the model incorporates the Illinois Waterway, 291 River Miles from Grafton, Illinois (River Mile 000) to Lockport, Illinois (River Mile 291). An additional $120K was provided in FY22 and Phase III of the model was complete. The entire UMR hydraulic model is now complete and is available for public use.

Additional Information

Congressional Districts

All within the Rock Island District

Authority

SI - Special Interest

Summarized Project Costs

Major Work Item Current Year

FY 2024:  This project was completed in FY22.  No further effort is required.

Major Work Item Next Fiscal Year

FY 2025:  No further effort is required.  Project is complete.