Green infrastructure is an economical solution for separating polluted stormwater runoff from clean water, according to a new report released jointly by the American Society of Landscape Architects (ASLA), American Rivers, the Water Environment Federation (WEF), and ECONorthwest. The report, “Banking on Green: How Green Infrastructure Saves Municipalities Money and Provides Economic Benefits Community-wide,” finds that environmentally friendly buildings save taxpayers’ dollars, help prevent flooding, and improve water quality, among other benefits. This report was produced in an effort to quantify the economic profits of green infrastructure.

“For many decades, landscape architects have been helping communities large and small manage their stormwater with innovative green infrastructure solutions, such as green roofs, rain gardens, bioswales, and pervious pavements,” says ASLA executive vice president Nancy Somerville.

Key report findings include: 

  • In addition to costing less than traditional infrastructure practices, green-infrastructure practices can further reduce costs of treating large amounts of polluted runoff.

  • Green infrastructure can help municipalities reduce energy expenses.

  • Green infrastructure can reduce flooding and related flood damage.

  • Green infrastructure improves public health by reducing bacteria and pollution in rivers and streams, which prevents gastrointestinal illnesses in swimmers and boaters.

New York City and Baton Rouge, La., are examples of two cities using green infrastructure to save municipal funds, according to the report. New York’s plan to reduce combined-sewage overflows involves using green infrastructure in place of traditional, or “gray,” infrastructure. The plan is estimated to save the city $1.5 billion over 20 years. A high school in Baton Rouge saved nearly $400,000 by using bioswales and a rain garden to reduce flooding instead of re-piping the site.

A PDF of the full report can be downloaded from the ASLA.