A contractor is hired to build a condominium on a parcel of land with an area of 4 hectares. In an effort to minimize runoff from the construction site, the contractor builds a sedimentation basin with a depth of 3 meters and an area of 400 m^2. At the same time a nearby town decides to build a sedimentation basin to intercept runoff from the town that is polluting a recreational lake. The town occupies an area of 250 hectares. About 50 percent of the town consists of impervious surfaces such as streets, parking lots, and roof tops. The town builds a sedimentation basin with a depth of 3 meters and an area of 4,000 m^2.