Floods are Illinois’ most common natural disaster, accounting for well over 90% of declared disasters. Flooding in certain areas is predictable; however, too many Illinois citizens experience personal and economic losses due to flooding of their homes and businesses.
ISWS’ Coordinated Hazard Assessment and Mapping Program (CHAMP) evaluates local flood hazards, identifies high-risk areas, and collaborates with community partners to inform, educate, and empower them to take action to prevent losses from natural hazards.
Flood Hazard Studies
CHAMP conducts hydrologic and hydraulic studies that comply with state and federal standards to revise county Flood Insurance Rate Maps, also known as FIRMs. This work is conducted for the Federal Emergency Management Agency and under contract with communities or other agencies. Staff provide the most up-to-date flood hazard data and facilitate communication with engineers, community officials, and the public.
The team also maintains an online map of publicly funded flood study sites. Engineers can use this resource to identify ongoing work.
Map Revision
Flood hazards are not static, and updates to flood maps may be necessary when changes impact the hydrologic or hydraulic features of a river or stream. Engineers and hydrologists on the CHAMP team provide consistent and efficient analyses and mapping services to community officials and stakeholders.
CHAMP reviews applications for Letters of Map Revision (LOMR) and Conditional Letters of Map Revision (CLOMR) to modify FIRMs as part of FEMA’s LOMR Delegation Program. FIRMs require ongoing reassessments due to changes in land use, climate, and available data.
CHAMP has produced updated digital FIRMs that illustrate flood-prone areas in nearly all Illinois counties. These maps illustrate the areas — almost 12% of the state — facing a 1% probability of flooding yearly.
CHAMP collaborates with the Illinois Department of Natural Resources Office of Water Resources and FEMA to identify Illinois communities that could benefit from updated engineering analyses and mapping services.
Community Engagement
CHAMP provides communities with high-quality flood maps, information, and tools for assessing flood risk and planning through outreach for FEMA’s Risk MAP Program. The program’s goal is to reduce flood damage.
CHAMP executes FEMA’s plan, which calls for ongoing engagement with state and local officials, as well as watershed stakeholders, through a series of meetings as part of the program. The process begins with discovery at the watershed level. Data is compiled, and then a discovery meeting is held to discuss flood issues and technical data needs with officials in communities that are wholly or partially located within the watershed. Local floodplain managers, community engineers, planners, developers, watershed groups, and other stakeholders participate in meetings, providing additional information and discussing flood issues, technical data needs, and the status of mitigation planning in the watershed. Watershed reports, maps, and data are available online.
Research Areas
CHAMP researchers apply the tools and knowledge they glean from conducting flood studies and collaborating with communities to identify research needs. Projects include trends in peak flows, the effects of urbanization, stormwater management, mitigation, climate change impacts, and detailed hydrologic and hydraulic modeling.
Digital Products
Detailed hydraulic studies can lead to a variety of impactful digital mapping products.
Using high-resolution digital terrain models, digital depth grid data can be generated to illustrate the depth of flooding for various frequency events (e.g., 10, 4, 2, 1, and 0.2% frequency), the frequency of flooding at a specific location in the floodplain, and the probability of inundation over 30 years. When combined with stream gage data and National Weather Service forecasts, the inundation areas for a specific flood stage can be mapped.
This data is shared with project stakeholders to make emergency management decisions. The Changes Since Last FIRM database is another tool available to monitor changes in FIRM data and updated study information.