Drainage systems manage excess water to protect infrastructure and the environment. Outdated commercial drainage systems may have improper grading and inadequate maintenance, which can lead to clogs or flooding. Sustainable, efficient drainage systems can offer environmental, economic and social benefits.
What Makes a Drainage System Sustainable?
Water traditionally moves through a direct network of pipes and sewers, but sustainable drainage systems are designed to mimic natural drainage processes. They move water locally — often filtering it into the soil — and consist of a combination of natural and man-made features. This helps combat common drainage problems, like erosion and path flooding.
In the U.S. (like various countries in the world), many parts are experiencing an increase in hourly rainfall due to climate change. Sustainable drainage systems are more adaptable to the effects of climate change, such as disrupted ecosystems. Here are common types of systems to consider for drainage projects:
- Basins: These store stormwater runoff and gradually drain it back into the ground. Detention basins completely drain after a storm, and retention basins maintain a permanent pool of water.
- Green roofs: As an alternative to shingles, soil and vegetation grow on these roofs, providing insulation and collecting rainwater.
- Permeable pavement: Water can pass through this porous pavement to prevent water pooling.
- Ponds: Natural and man-made ponds store water and create an ecosystem enjoyed by humans, animals and plants.
- Rain gardens: These shallow depressions collect and filter runoff water, and they can be aesthetically pleasing.
- Soakaways: Using specialized crates, these large holes in the ground collect and drain water.
- Swales: These sunken channels contain vegetation and filter pollutants from water as it goes into the soil.
- Wetlands: Wetland areas — like marshes and bogs — act like natural sponges to control flooding and store carbon.
Advantages of Sustainable Drainage Systems
Sustainable drainage systems meet the triple bottom line (TBL), which benefits people, the planet and the economy. This framework challenges industries and companies to have broader positive impacts rather than solely focusing on profits. Below is a breakdown of how sustainable drainage systems achieve the TBL standard:
Social Benefits
Drainage systems provide health, safety and community value. Adding greenery-filled spaces to urban areas and recreational spaces can reduce urban heat and foster well-being. The National Parks and Recreation Association suggests that nature is essential for human development, finding that people living in areas with few green spaces have a 44% increase in anxiety disorders and 33% increase in physician-diagnosed depression.
Environmental Benefits
A sustainable drainage system has many environmental advantages. It can protect structures and the soil by mitigating water pooling after heavy rain. Some regions even require commercial properties to use appropriate drainage systems by law.
These systems also improve water quality for humans and animals because pollutants — like sediment and oils — are filtered out before water reaches a larger body of water. Filtering water into the soil also replenishes groundwater resources. In addition, ponds and other natural spaces can benefit biodiversity by serving as habitats for wildlife.
Economic Benefits
Sustainable drainage systems prove cost savings and long-term value. The initial cost depends on the scale of a given project. For instance, adding a rain garden to a residential property is typically less expensive than paving an urban sidewalk with permeable concrete.
Natural drainage projects promote long-term value. Significantly reducing the risk of flooding can protect infrastructure, leading to reduced repairs from water damage and lower insurance premiums. This can increase property value.
Integrating Smart Technologies in Sustainable Drainage
Implementing smart technologies can further improve the drainage system. These technologies can collect and analyze data to optimize performance and predict maintenance timelines. They offer a dynamic response to changing weather and climate conditions.
Here are several applications of smart technologies for these projects:
- Live monitoring and data collection: Internet of Things sensors can examine water quality and flow to detect blockages, overflows and pollution.
- Adaptive management: Automated controls can use weather forecasts and other data to open or close drainage gates.
- Predictive analytics: AI can examine current and historical data to identify potential risks and improve maintenance timelines.
- Integration with building management systems: Combine smart technologies with other systems to create a holistic water management plan.
Philadelphia’s Green City Waters plan, Singapore’s Smart Drainage program and other similar initiatives use AI-driven technology to support sustainable drainage systems. As technology continues to develop, it could benefit communities and the planet even more.
Best Practices for Triple Bottom Line Drainage Design
Drainage systems should be designed with the TBL and opportunities for cross-departmental collaboration in mind. When multiple parties work together, they can optimize sustainable drainage’s ability to manage water quantity and quality, promote social equity, and boost long-term savings.
Sustainable certification programs offer frameworks and resources for creating environmentally friendly properties. The Leadership in Energy and Environmental Design (LEED) and SITES certifications can be used independently or in tandem.
LEED-certified buildings have a reduced environmental impact, taking carbon footprint and energy usage into account. This globally recognized certification can lower utility bills by 25% and has been implemented by 100,000 projects. SITES measures the performance of everything on a site, with a focus on mitigating climate change and enhancing biodiversity.
Drainage systems should be continuously monitored and adapted over time to keep them in optimal condition.
Going Forward With Sustainable Drainage
When projects are designed with the people and planet in mind and not just profit, they can positively impact the environment and communities. Engineers, designers and stakeholders should look for opportunities to implement sustainable design into drainage systems and other projects.
