Infiltration Facilities
Infiltration Basin
Infiltration basins are shallow depressed areas designed to hold water volume and constructed over permeable soils that allow percolation into the ground.
Subsurface Infiltration Gallery
A subsurface infiltration gallery is made up of underground vaults or pipes that store and infiltrate stormwater.
Drywell
A drywell is a bored, drilled, or driven shaft or hole where the depth is greater than its width. Drywells are designed to intercept and store runoff while infiltrating into the ground.
Permeable Surface/Pavement
Permeable surfaces/pavements are porous urban surfaces with an underlying gravel reservoir to store runoff before it infiltrates into the subsoil.
Bioretention Basin/Swale
A bioretention basin/swale is a vegetated shallow depression that is designed to receive, retain, and infiltrate/treat stormwater runoff from downspouts, piped inlets, or sheet flow from adjoining paved areas.
Treatment BMPs
Pretreatment BMPs
Pretreatment BMPs are often proposed to remove contaminants, including heavy metals, sediments, trash, and hydrocarbons, before stormwater is infiltrated. Pretreatment BMPs are easier to maintain and will help extend the life expectancy of the downstream infiltration facility.
Tree Box Filters
Tree box filters are concrete containers with vegetation and filter media. Runoff typically enters the tree box through a curb cut opening or pipe. Tree box filters pretreat flows by capturing, immobilizing, and decomposing pollutants and nutrients, which are incorporated into the vegetation system.
Vegetated Swales
A vegetated swale is an engineered, shallow, landscaped depression with compost-amended soils and native vegetation. They are designed to capture urban runoff, temporarily store, settle, and filter out pollutants and sediment from lawns, rooftops, roads, parking lots, driveways, and sidewalks. Vegetated swales are very similar to bioretention basins/swales.
Sewer Diversions
Sewer diversions are used to convey runoff to the sanitary sewer for ultimate treatment (and sometimes use as recycled water). Sewer diversions generally include a diversion, pump, storage system, and sewer connection.
Finding the Right Solution
The Master Plan will help the City identify and create projects that make meaningful impacts on the community. The right combination of these tested and effective systems will improve water quality and retention within the City. Water is a valuable resource and it should be handled responsibly. By planning out how to best capture and clean the water, the City also reduces flooding and pollution of our environment. A well-organized Stormwater Master Plan improves the world where we live, work, and play.