Flooding is an ever-increasing challenge for communities around the world, and effectively managing wastewater is a critical part of the solution. As extreme weather events become more frequent due to climate change, traditional “gray” infrastructure like sewers and treatment plants are struggling to keep up. Innovative ”green” stormwater management approaches, however, are proving to be more resilient and cost-effective alternatives.
Now, this might seem counterintuitive…
Reimagining Urban Water Infrastructure
Across the globe, cities are grappling with the impacts of aging, overwhelmed wastewater systems. Combined sewer overflows (CSOs) – where stormwater and sewage flow through the same pipes – are a major culprit, causing billions of gallons of untreated waste to pollute waterways every year. In New York City alone, over 27 billion gallons of raw sewage and runoff are discharged annually from 460 CSO outfalls.
Upgrading these antiquated systems is a daunting challenge, with the U.S. EPA estimating $150 billion in needed investments over the next two decades. Many municipalities simply cannot afford the astronomical costs of expanding traditional “gray” infrastructure like deep underground storage tunnels.
Fortunately, green infrastructure offers a more sustainable and affordable solution. By harnessing natural processes to capture, filter, and reuse stormwater, these nature-based systems not only reduce flood risks but also provide a host of co-benefits for local communities.
Embracing Natural Solutions
Green infrastructure encompasses a variety of landscape-based practices, from permeable pavements and rain gardens to constructed wetlands and green roofs. These features work by mimicking the natural water cycle, allowing rainfall to soak into the ground, evaporate back into the atmosphere, or be stored for later use.
In contrast to the “gray” pipes and concrete of traditional stormwater management, green infrastructure promotes water retention and water quality improvements. When rainfall hits impervious surfaces like roads and rooftops, it picks up pollutants like oil, heavy metals, and bacteria before rushing into nearby waterways. Green infrastructure intercepts this runoff, allowing it to be filtered through soil and plant life.
This approach not only reduces the volume of stormwater entering sewer systems, but also improves the quality of the water that does. Studies have shown green infrastructure can remove up to 90% of sediment, 80% of trace metals, and 65% of phosphorus from runoff.
Cost-Effective Flood Mitigation
Beyond water management benefits, green infrastructure often proves to be a more economical option compared to traditional “gray” approaches. Philadelphia, for example, found that its green infrastructure plan would cost $2.4 billion over 25 years – less than a quarter of the $9.6 billion bill for expanding its sewer system.
Green infrastructure can also provide significant long-term savings. Permeable pavement, for instance, may have higher initial installation costs, but its lifespan can be twice that of conventional asphalt, with much lower maintenance requirements. The Iowa town of West Union calculated it could save $2.5 million over the lifetime of a single parking lot by using permeable pavement instead of traditional paving.
These cost advantages are especially important for cash-strapped municipalities facing the dual challenge of aging infrastructure and increasingly severe weather events. By reducing the burden on existing sewer systems, green infrastructure can help avoid the astronomical price tag of expanding or replacing them.
Multifunctional Community Assets
While the stormwater management capabilities of green infrastructure are crucial, these nature-based systems offer a wide range of additional benefits for local communities. By incorporating elements like parks, urban forests, and constructed wetlands, green infrastructure can enhance urban livability, improve public health, and boost local economies.
Vegetated features like green roofs and rain gardens, for example, can lower urban air temperatures, improve air quality, and sequester carbon – all of which are valuable in the face of climate change. Bioswales and permeable pavements also help recharge groundwater supplies, supplementing or even reducing the need for potable water withdrawals.
Green infrastructure can also boost property values, stimulate economic activity, and create local jobs. A meta-analysis found that proximity to green spaces can increase residential property values by up to 20%. And by reducing flooding and improving environmental quality, these nature-based systems can safeguard important community assets like homes, businesses, and recreational areas.
Perhaps most importantly, green infrastructure can help address long-standing inequities in urban development. By incorporating parks, gardens, and other green amenities into traditionally underserved neighborhoods, these projects can provide much-needed access to natural spaces and their associated health and quality-of-life benefits.
Overcoming Barriers to Implementation
Despite the clear advantages of green infrastructure, widespread adoption faces several key challenges. Outdated regulations, siloed government agencies, and limited funding sources can all hinder progress. Securing long-term maintenance and monitoring is another common obstacle, as these nature-based systems require ongoing care to function effectively.
Innovative financing mechanisms, like public-private partnerships and green infrastructure banks, can help overcome these hurdles. Philadelphia’s Green City, Clean Waters program, for example, utilizes competitive grants to incentivize private property owners to install green stormwater features. And in Oakland, California, the city partnered with a local nonprofit to establish a “Green Stormwater Infrastructure Fund” that provides grants and technical assistance to community-led projects.
Strengthening regulations and building political will are also critical. Municipalities can update zoning codes, stormwater permits, and construction standards to prioritize green infrastructure, while state and federal policies can provide funding, technical guidance, and other support. The U.S. Environmental Protection Agency, for instance, has developed a suite of tools and resources to help local governments plan, implement, and maintain green stormwater systems.
Embracing the Future of Water Management
As climate change continues to intensify the frequency and severity of extreme weather events, traditional “gray” infrastructure is proving increasingly inadequate. Innovative green stormwater management approaches, however, offer a more resilient, cost-effective, and community-centric solution.
By harnessing the power of nature, green infrastructure can reduce flood risks, improve water quality, and provide a wide range of co-benefits for local communities. From permeable pavements and rain gardens to constructed wetlands and green roofs, these nature-based systems are transforming the way we think about urban water management.
Of course, realizing the full potential of green infrastructure will require overcoming various institutional and financial barriers. But by working collaboratively across sectors and levels of government, communities can develop integrated, equitable, and sustainable approaches to water resources that safeguard our cities, our environment, and our shared future.
To learn more about innovative flood control and water management strategies, be sure to visit the Flood Control 2015 website. There you’ll find a wealth of resources, case studies, and expert insights to help your community build resilience in the face of a changing climate.
Tip: Implement real-time monitoring to swiftly respond to flood risks
