The Browne Mountain Regional Stormwater Facility was a water quality retrofit project constructed in 2008. The facility is located in south Spokane, in the Glenrose Watershed, below Browne Mountain. The project was constructed on a decommissioned City of Spokane sewage lagoon site. The facility receives stormwater runoff from the Browne Mountain drainage sub-basin, which is a part of the Glenrose Watershed.
The site has always intercepted untreated stormwater and groundwater runoff that was routed around the sewage lagoon. The facility was an amendment to a small combination detention / treatment pond located with the Inverness/Glengrae residential subdivision. The stormwater system includes a sediment pond prior to a very large bio-infiltration pond. A meandering channel in the bottom of the infiltration pond reduces erosion and provides filtration of pollutants in lower flows. The facility receives stormwater runoff and groundwater that flow year round. There are two metered outflow structures; one between the sediment and infiltration pond, and one at the outlet to the Glenrose Channel, that can safely bypass the 2, 25, 50 and 100 year storms.
The sediment pond has turned into a lush and vibrant wetland habitat. The facility includes trees, bushes and drought tolerant grasses and native groundcover. The majority of the site takes on a different appearance with each season; mowed down once or twice a year in the larger open areas.