Urban tree canopy and other vegetation (also called Green Stormwater Infrastructure (or GSI)) mitigates stormwater run-off by intercepting precipitation which can be absorbed by the vegetation and infiltrated into the soil.  This results in reduced run-off during heavy rain events which in-turn reduces the cost of traditional stormwater infrastructure (gray infrastructure) and reduces water pollution into our rivers and streams.  

Treasure Valley's tree canopy mitigates 125 million gallons of stormwater annually, saving $1.1 million in infrastructure costs.  Through future strategic tree planting (showcased below), we can further improve stormwater benefits throughout our region.  

Learn more about local GSI planning efforts.

Local Green Stormwater Infrastructure (GSI) Resources created by our partners:

• Ada County Highway District (ACHD) GSI fact sheets:
  • Bio-swales
  • Bioretention Areas
  • Permeable Pavers
  • Tree Systems
• Fairview Avenue Green Street Conceptual Design (ACHD, EPA, Tetra Tech - July 2015)
• GSI Economics in the Boise Urban Area (Idaho Rivers United - December 2015)
• Boise Subwatershed Plan -- Americana and Main Street (ACHD, Ecosystem Sciences - June 2016)