Overview

HEC-FIA (Flood Impact Analysis) is a tool used to help identify the consequences from a single flood event. HEC-FIA computes can include economic losses (losses to structures and their contents), agricultural losses, and expected life loss from these hydraulic events. A dollar value of the benefit to the nation from USACE dam and levee projects is calculated every year and published in the Annual Flood Damages Report (AFDR) to Congress. CWMS plays a vital role in the reporting of AFDR through the use of HEC-FIA to calculate the flood damages reduced for each Corps project. Developments to HEC-FIA are currently focused on improving the process, functionality, and reporting options of flood damages reduced simulations in CWMS. 

Accomplishments

HEC-FIA 3.3 was released in the first quarter of FY23. A new inundation configuration (Holdout – RAS HDF) allows for more flexibility in flood damages reduced computations. Instead of accepting only two hydraulic inputs (regulated and unregulated), this configuration accepts two additional hydraulic inputs: the regulated without-levee and the unregulated without-levee conditions. This added functionality allows districts to develop a without-levee inundation simulation in HEC-RAS, instead of relying HEC-FIA to estimate the without-levee scenarios. This new inundation configuration uses native HEC-RAS HDF output, no longer relying on large .tif files that take additional time to generate in HEC-RAS Mapper. The new version also allows users to launch HEC-RAS Mapper from within HEC-FIA, giving users easier quality control of HEC-FIA results by comparing the results against HEC-RAS inundations.

Two beta versions of HEC-FIA 3.4 were also released to the field, which included the initial addition of the ability to calculate agriculture flood damages reduced. This includes calculating both the agricultural damages reduced and the acreage flooded reduced by the presence of dams and levees. Bug fixes, minor features, and speed enhancements were also included in the beta releases.

Field Support and Technology Transfer

Throughout the year, the HEC-FIA and Flood Damages Reduced team held individual working sessions with district Water Management offices to help support their use of CWMS and HEC-FIA to calculate AFDR for their projects. These working sessions covered advice on modeling approach, workflow suggestions, and technical assistance. The team also provided help to individuals through the HEC-FIA Discourse page, Microsoft Teams CWMS FIA channel, and via email. In FY23, the Flood Damages Reduced team also organized and began preparing material to host a Flood Damages Reduced workshop in the first quarter of FY24.