Progress Ridge, a 110-acre mixed-use development, is designed around a reclaimed rock quarry on the border between the cities of Beaverton and Tigard, Ore. The quarry is now an 11-acre lake surrounded by 746 high-density residential units, a commercial town center and 43 acres of parkland.
Beaverton requires on-site detention of stormwater runoff to control the volume of runoff sent to downstream channels. This protects channels from scouring and reduces potential flooding. Under EPA permit regulations, a specific level of water quality is required before discharging runoff into downstream waterways.