Abstract

Hydrologic Analysis of Existing Terrain and Proposed Stormwater Source Controls
Track: Water Resources
Authors: Erik Strandhagen

Integral Consulting Inc. performed hydrologic drainage analysis and designed composite surface terrain to model stormwater source control measures at a former industrial site in Portland, Oregon. The hydrologic drainage analysis of the existing (preconstruction) and post-construction site non-dendritic terrain DEMs utilized ArcGIS ssoftware and the ArcHydro extension. Engineer-designed stormwater remedy elements, including basins, channels, berms, and fill areas, were incorporated with existing terrain using Autodesk Autocad Civil 3D software. Drainage analysis of the post-construction DEM delineated site drainage, the longest flow paths, and catchment areas. Integral produced a high-resolution land cover layer of the site to characterize the channel and catchment land cover types. Volumetric flood inundation modeling of the post-construction DEM surface indicates the stormwater source controls are capable of supporting a 100-year flood event. The resulting hydrologic geospatial analysis illustrates that the proposed stormwater conveyance system will capture the majority of stormwater runoff from the site.