Software Wins Innovation Award for Predictive Flooding Capabilities Following Fires

The Institute for Water Resources’ (IWR) Hydrologic Engineering Center (HEC), located in Davis, California, took home the U.S. Army Corps of Engineers (USACE) Innovation of the Year Award for adding Post-Wildfire Modeling capabilities to its software. These software capabilities provide prediction tools that engineers can use to anticipate a unique type of flooding that can follow a combination of fire and floods.

The software development was led by a USACE project delivery team with collaboration between HEC, the Engineer Research and Development Center’s (ERDC) Coastal and Hydraulics Laboratory, and USACE district engineers, who incorporated the post-wildfire modeling capabilities into HEC’s hydrology and hydraulic software.  What resulted was award-winning predictive capabilities that advances the nation’s fight against floods, and especially post-wildfire flooding.

Hydrologic Engineering Center Director Chris Dunn highlighted the significance of the achievement. “The team’s efforts culminated in truly groundbreaking capabilities, which are of great value to the nation and to the engineers who use the tools. The engineers analyze watersheds where wildfires have occurred, and they attempt to predict what could happen in watersheds where wildfires may occur in the future. The incorporation of these capabilities into Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) and Hydrologic Engineering Center-River Analysis System (HEC-RAS) will better help engineers, emergency planners, and the public understand their risks and appropriately prepare. A big part of our jobs is to understand and help others understand their risks. These capabilities have helped us to do so in a big way.”


According to Stanford Gibson, HEC’s sediment transport specialist, the modeling tool is increasingly relevant due to an uptick in wildfires in the western United States and the destructive or deadly nature of wildfires, and the potential for mud and debris flows to follow. “Wildfires are kind of a big deal these days. But after the wildfire, the danger isn’t over. The fire changes the landscape, so subsequent rain can cause sudden mud and debris flows. We added analysis tools to our software – which is already industry standard for flood risk – to forecast the impact of these events and plan emergency management actions,” Gibson said.

Specifically, the models are now superpowered by a library of new equations to handle the unique physics of these events, which improves the agency’s ability to more anticipate the likelihood and magnitude of a post-fire event, where it will flow, and how deep the flooding will be. “This is crucial for emergency assessments and mitigation measures,” said Jay Pak, Ph.D., HEC hydraulic engineer, “as it allows USACE to more accurately predict post-fire flood risk and respond accordingly. Additionally, the establishment of a long-term modeling framework enables USACE to continuously simulate post-fire flooding, debris flow risk, and ecology recovery in downstream ecosystems and communities over a 10-year period.”

Students at the inaugural U.S. Army Corps of Engineers (USACE) post-wildfire modeling class mixing miniature debris flows to explore the effect of model parameters on laboratory-scale mudflows. The Institute for Water Resources’(IWR) Hydrologic Engineering Center (HEC), located in Davis, California, won the USACE Innovation of the Year Award for adding post-wildfire modeling capabilities to its software. USACE PHOTO

These capabilities are critical for USACE, as the agency has a role in responding to post-wildfire hazards. “As the nation’s premier flood risk agency, our partners turn to us when they face any kind of flood risk, whether the water is blue [traditional flood water] or brown [mud and debris-filled flood waters]. They expect us to have the capabilities to forecast their flood risk and evaluate mitigation alternatives, no matter the scenario, which requires increased analysis since the physics of mud and debris flows is more complicated than water. This effort got the tools our Corps districts need into their hands to meet these expectations for post-wildfire hazards,” Gibson said.

In addition to increasing predictive capabilities and response efforts, the software also increases opportunities for collaboration among key partners, thanks in part to the research and development touchpoints occurring between state, local, and federal agencies utilizing the software. Pak emphasized that such cross-agency collaboration can lead to more effective and efficient emergency response and risk mitigation measures, such as was recognized in the innovation award. “The team behind this innovation can be proud of the fact that we developed new capabilities in the HEC-Hydrologic Modeling System [HEC-HMS] and the HEC-River Analysis System [HEC-RAS] from scratch through research, software development, technical transfer, and applications. This is a significant achievement that required a lot of hard work, collaboration, and expertise from multiple organizations and individuals. The fact that we were able to develop these capabilities from scratch demonstrates our innovation, creativity, and dedication to improving emergency assessments and mitigation measures for post-fire hydrological phenomenon. This award is a recognition of our hard work and a testament to the impact that our innovation can have on protecting communities and infrastructure from the effects of post-fire flooding,” said Pak. He also added, “Personally, this was a dream come true for me, as it provided a once-in-a-lifetime opportunity to utilize my previous Ph.D. research in developing new capabilities for post-wildfire hydrology and debris flow.”

Research Hydraulic engineer for the U.S. Army Corps of Engineers (USACE), Institute for Water Resources Jay Pak, Ph.D., (pictured), teaches the first USACE workshop on post-wildfire modeling with these tools at the Desert Research Institute in Nevada. Also instructing, (not pictured) was IWR – Hydrologic Engineering Center, sediment transport specialist Stanford Gibson. The Institute for Water Resources’(IWR) Hydrologic Engineering Center (HEC), located in Davis, California, was named USACE Innovation of the Year Award for adding post-wildfire modeling capabilities to its software. USACE PHOTO

Gibson also reflected upon the team’s achievement, acknowledging the truly innovative approach required. “The hydraulics include some pretty ‘crunchy’ math. Mud and debris flows aren’t water, and require new physics and theory. It delves into the world of rheology [which partly studies the flow of complex liquids] and non-Newtonian physics [which studies fluids that depart from Newton’s viscosity assumptions], both of which are fun for someone like me,” said Gibson. “But by getting it into HEC-RAS, the flood risk model that our agency (and approximately 100,000 people around the world) already use, we got these capabilities into the field, and they were used in planning and emergency management studies in four different USACE districts within a year of release. We trained more than 40 people on these tools at the first class in late April, which means that within a couple years of their release they are just part of the Corp’s wildfire response,” Gibson added.

Gibson also addressed key players in the achievement, saying, “We collaborated with USACE Engineer Research and Development Center [ERDC] to develop the algorithms and library … particularly Dr. Ian Floyd, ERDC research physical scientist, and Dr. Alex Sánchez, senior hydraulic engineer at HEC, did a lot of the HEC-RAS development.”


The PDT is also releasing web videos on the theory and practice behind these new methods. The post-wildfire team has developed seven videos on these topics that have been viewed more than 7,500 times since their release. The team has embedded these videos directly into the online user help features, making them directly accessible from the software.

Visit to learn more about this innovative capability or to access a training material link, which is a portal to the HMS capabilities and videos.

About HEC:

The primary goal of the Hydrologic Engineering Center (CEIWR-HEC) is to support the nation in its water resources management responsibilities by increasing the U.S. Army Corps of Engineers (USACE) technical capability in hydrologic engineering and water resources planning and management. One way CEIWR-HEC accomplishes this goal is by bringing state-of-the-art research and development into state-of-the-practice, which advances hydrologic engineering and water resources planning.

This article is featured in the 2023-2024 edition of America’s Engineers: The People, Programs, and Projects of the U.S. Army Corps of Engineers


Subscribe to the America's Engineers newsletter and never miss out on any of the recent stories about the incredible people, programs, and projects of the U.S. Army Corps of Engineers.

You have successfully subscribed to the newsletter

There was an error while trying to send your request. Please try again.

America's Engineers will use the information you provide on this form to be in touch with you and to provide updates and marketing.