29-acre natural catchment area slated for residential development. The site’s topography is illustrated in Figure 1-1, and the planned development is shown in Figure 1-2. The layout preserves natural slopes, while residential lots slope at 2% for drainage. Stormwater will drain to a stream via a culvert under a southeast-side street.
The aim is to estimate post-development stormwater discharges at the catchment outlet, comparing them to pre-development conditions. Synthetic design storms with various return periods will be applied using the standard approach from stormwater drainage manuals.
Two models will be created: one reflecting the current state and another representing the fully developed condition. Initial discharge estimates will focus on overland flow without channelized flows. The subsequent example will introduce conveyance elements.