The City and County of Denver is making green infrastructure a fundamental part of the city’s long-term stormwater management strategy by looking at ways to incorporate large-scale green infrastructure with small or site-scale green infrastructure. On a large scale, green infrastructure refers to a network of parks, open spaces, drainageways, and floodplains which help mitigate the impacts caused by impervious (hard) surfaces. Site-scale green infrastructure refers to smaller, engineered, structural practices which mimic larger natural systems and use vegetation, soils, and roots to slow and filter stormwater runoff.
Site-scale green infrastructure best management practices (BMPs) are the focus of Denver’s new Ultra-Urban Green Infrastructure Guidelines. Detailed fact sheets for streetside stormwater planters, bumpout stormwater planters, green gutters, green alleys, and tree pit/ tree trenches are included within the Guidelines. Each practice within the Ultra-Urban Green Infrastructure Guidelines has been chosen for its suitability in Denver’s dense, urban environment and in particular for use in the right-of-way and on private redevelopment and infill sites.
Benefits of green infrastructure, regardless of scale, include improved water quality but also include better air quality, reduced flooding risks, urban heat island effect mitigation, reduced energy demands, climate change resiliency, and enhanced community livability.
Example of a stormwater tree trench on Denver city street