Using a Flow Dynamics 2D Model to Develop Street Flooding Solutions in a Highly Transited Urban Area

摘要

The City of Cambridge, MA has been experiencing recurrent street flooding in a highly populated and transited street intersection. One of the main reasons for the street flooding occurrence stems from inadequate stormwater collection system, specifically catch basins inlet capacity. Typically, inlet capacity studies are performed using spreadsheet calculation analyses in which stormwater inlet inflow and transfer to neighboring inlets rely on semi-empirical formulae based on terrain and inlet configuration. However, such methodology assumes instantaneous transfer of flow between inlets, neglecting the effects on inlet performance associated with topography-related flow momentum transfer, leading in many cases to unreliable results. Therefore, the City elected to use a two-dimensional hydraulic computational model to more accurately simulate the flow dynamics over the terrain surface in order to enhance results reliability in evaluating inlet capacity, and assist in devising street flooding mitigation solutions. This paper details the results from a catch basin inlet capacity analysis using a 2D hydraulic model, a series of proposed collection system improvements, the lessons learned, and main conclusions.