Using Dynamic Stormwater Modeling as a Public Involvement Tool
For more information, contact Kelly Dillard.
Obtaining public input and buy-in is often a critical component of stormwater management design projects, and effectively demonstrating the need for and potential effects of a proposed project is crucial to successfully communicating with the general public and keeping a project on track. Visual illustrations often prove to be the most valuable and efficient means of demonstrating a project’s effects to the public, and the introduction of dynamic stormwater modeling software presents a new tool to provide improved information graphics for public involvement use.
What Is Dynamic Modeling?
Dynamic modeling, sometimes referred to as unsteady modeling, considers the behavior of drainage systems over time by solving the hydraulic equations at each time step during a storm’s duration, rather than just peak flow conditions. Dynamic modeling can automatically handle split flows, overflows and backflows while reporting flow, depth and volume over time. The combination of these features results in an accurate depiction of the drainage conditions, especially in complex flooding situations. In addition to the superior technical results, many dynamic modeling software packages have the ability to display results in an effective manner to both technical and non-technical audiences. One of their most valuable features is their capability to produce graphics and animations to dynamically illustrate stormwater flow through storm drain systems, open channels and overland flow paths. Storm sewer system hydraulic grade line profiles and ground surface flood inundation maps can be created to illustrate flooding effects versus time for various intensity storms. These flood inundation maps and other graphics can be particularly useful for demonstrating the need for a project as well as illustrating multiple potential solutions for flooding issues.
Success in the City of Arlington
FNI recently successfully used dynamic modeling to evaluate existing conditions and proposed drainage improvement alternatives for alleviating the repetitive flooding of approximately 30 homes in the Green Meadows subdivision in Arlington, Texas. Drainage improvement alternatives previously developed by the City were not well received by the residents, due to proposed tree removal and undesirable design features. As such, FNI recognized this project would be under significant public scrutiny and elected to use InfoWorks SD dynamic modeling to better demonstrate existing conditions and proposed design alternatives to residents in the project area.
FNI and City staff held three public meetings with residents to keep them involved in the decision making process. Through the use of dynamic modeling, FNI presented animations of the flooding occurring in the neighborhood, and the residents were able to better visualize the area’s existing conditions as well as the results of potential design alternatives. This helped build the residents’ trust and confidence in FNI’s engineering expertise, which in turn allowed them to establish trust and confidence in the proposed drainage improvement alternatives and enabled consensus building to take place. The selected alternative is currently under design.