River Hydraulics Model Quantifies Flooding Impacts

$2.5 MILLION SAVINGS PER YEAR IN RIVER HYDRAULIC STUDIES

Engineers across the world now have more advanced and detailed hydraulic modeling tools to solve real-world problems. The Corps’ Hydrologic Engineering Center’s River Analysis System (HECRAS) visualization tools, such as RAS Mapper, help modelers better understand the hydraulic results and make it much easier to convey those modeling results to decision makers and the public. More than 95 percent of all Corps riverine hydraulic studies use HEC-RAS. More than 95 percent of all FEMA floodplain and floodway studies performed over the past 20 years were developed with HEC-RAS. Adopted by the National Weather Service, FEMA and the Department of Transportation for a variety of uses, HEC-RAS simplifies coordination between federal agencies during emergencies.

PROBLEM: High river levels from increased runoff from rain and snowmelt are a threat to both life and property. Tools are needed to assist local governments, resource managers and emergency management during these extreme events. The tools are required to estimate flood levels, provide information to guide reservoir operations, evaluate the potential for levee overtopping and breaching, produce flood inundation maps, and estimate consequences of levee and dam failure.

SOLUTION: Research has added many new features and tools to HEC-RAS to improve hydraulic modeling accuracy. Improved software workflow has reduced the time and cost to develop and calibrate a model. These improvements have also allowed for a much quicker response during flood emergencies. For example, an HEC-RAS model was rapidly created during a flood event for the Arkansas River. This model was used for forecasting, inundation mapping, and breach scenarios for the 2019 floods.

IMPACT: HEC-RAS has more than 100,000 users internationally from 200 countries. The software is applied to thousands of applications world-wide every year. Research investments in HEC-RAS have saved approximately 50 percent time on studies such as for the Arkansas River, where it also saved approximately $50 thousand per similar application. Assuming 50 of these type of studies per year are conducted Corps-wide, R&D improvements are resulting in $2.5 million in savings annually.