Water: Green Infrastructure
Why Green Infrastructure?
Green infrastructure is a cost-effective and resilient approach to our water infrastructure needs that provides many community benefits.
As of 2008, the total reported water infrastructure needs for the United States included $63.6 billion for combined sewer overflow control and $42.3 billion for stormwater management. Since only 22% of regulated MS4s are included in this estimate, the need for stormwater management is likely much greater. As communities develop and climate patterns shift, these needs can only be expected to grow. While single-purpose gray stormwater infrastructure is largely designed to move urban stormwater away from the built environment, green infrastructure reduces and treats stormwater at its source while delivering many other environmental, social, and economic benefits. These benefits not only promote urban livability, but also add to the bottom line.
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Flooding: Conventional stormwater infrastructure quickly drains stormwater to rivers and streams, increasing peak flows and flood risk. Green infrastructure can mitigate flood risk by slowing and reducing stormwater discharges.
Private and Public Cost Savings: When stormwater management systems are based on green infrastructure rather than gray infrastructure, developers often experience lower capital costs (PDF) (37 pp, 770K, About PDF). These savings derive from lower costs for site grading, paving, and landscaping, and smaller or eliminated piping and detention facilities. In cities with combined sewer systems, green infrastructure controls may cost less than conventional controls (PDF) (28 pp, 4.2MB, About PDF), and green-gray approaches can reduce public expenditures on stormwater infrastructure.
Particulate Pollution: Particulate matter refers to the tiny bits of dust, chemicals, and metals suspended in the air we breathe. Because particulate matter is so small, it can enter into the lungs and cause serious health effects. Trees, parks, and other green infrastructure features can reduce particulate pollution (PDF) (7 pp, 51K, About PDF) by absorbing and filtering particulate matter.
Health Effects: Breathing ground level ozone and particulate pollution can cause respiratory ailments including chest pain, coughing, aggravation of asthma, and even premature death. In their triple bottom line study (PDF) (160 pp, 2.5MB, About PDF) on the benefits of green infrastructure, the City of Philadelphia found that increased tree canopy would reduce ozone and particulate pollution levels enough to significantly reduce mortality, hospital admissions, and work loss days.
Energy Use: By reducing local temperatures (PDF) (9 pp, 225K, About PDF) and shading building surfaces, green infrastructure lessens the cooling and heating demand for buildings, reducing energy needs and decreasing emissions from power plants.
Climate Change: As different parts of the country become drier, wetter, or hotter, green infrastructure can help communities improve resiliency (PDF) (2 pp, 1MB, About PDF) and adapt to climate change (PDF) (52 pp, 2.3MB, About PDF) by increasing the capacity of drainage systems to handle large storms, increasing the resilience of water supply systems in times of drought, and mitigating the urban heat island effect. Urban vegetation can also mitigate climate change by reducing the levels of greenhouse gases in the atmosphere.
Water/Energy Nexus: Treating and moving drinking water and wastewater takes a lot of energy (PDF) (4 pp, 763K, About PDF). By reducing stormwater inflow into sewer systems, recharging aquifers, and conserving water, green infrastructure can significantly reduce energy use.
Habitat Connectivity: Large scale green infrastructure, such as parks and urban forests, also help to facilitate wildlife movement and connect wildlife populations between habitats. Learn how Loxahatchee, Florida is protecting the local watershed and conserving native ecosystems through the Loxahatchee Regional Greenways System.
Health Benefits: More green space and parks encourages outdoor physical activity, reducing obesity and preventing associated chronic diseases such as heart disease, high blood pressure, stroke, Type II diabetes, arthritis, and certain kinds of cancer.
Recreation space: Green infrastructure’s vegetation and trees can increase publicly available recreation areas, allowing urban communities to enjoy greenery without leaving the city. Additionally, green infrastructure’s vegetation and permeable pavements can reduce noise pollution (PDF) (80 pp, 16.3MB, About PDF) by damping traffic, train, or plane noise.
Property values: By utilizing green infrastructure in construction and increasing vegetation and tree cover, green infrastructure can increase property values (PDF) (40 pp, 429K, About PDF), benefiting both developers and homeowners.