What is the purpose of the step-backwater computer model?

The step-backwater computer model serves primarily to design floodway maps, which is crucial in floodplain management and regulation. This model simulates the flow of water through channels and floodplains, allowing planners and engineers to analyze how water levels change in response to various conditions, such as changes in riverbank topography or flood control structures. The outcome of this analysis helps determine areas that would be covered by floodwaters, thus informing the creation of floodway maps that delineate the boundaries within which development or construction is regulated to reduce flood risk.

By effectively providing data on water surface elevations and floodplain boundaries, the step-backwater model supports floodplain management efforts, ensuring that land-use decisions consider potential flooding impacts. This function is essential for compliance with National Flood Insurance Program (NFIP) requirements, which mandate that communities adopt and enforce floodplain management regulations based on accurate and reliable data regarding flood risks.