Rainfall, snowmelt, and torrential weather all lead to an abundance of water. In natural areas, this water would be absorbed into the ground and gradually dispersed over foliage, but in communities where roadways, sidewalks, homes, and other structures exist, this water has to go somewhere else. Here's how civil engineers, planners, and project managers are re-thinking stormwater management to reduce costs and improve outcomes.
The Best Stormwater Management Practices
Traditionally, stormwater is directed to a drainage system under roadways, but these systems are far from flawless. It just takes one clogged drain for roads to begin flooding, causing hazardous driving conditions and potentially millions of dollars in property damage. Even without a clogged drain, it's possible for systems to become overwhelmed and backed up when the rate of runoff exceeds the system's capacity.
Instead of building bigger drainage systems, communities are shifting away from impervious areas that contribute to stormwater management complications and instead are adopting low-impact designs that enable stormwater to almost manage itself. As the EPA explains, low-impact development (LID) is a concept that combines systems and techniques designed to mimic natural water filtration and evaporation. LID helps protect the quality of water sources and local aquatic habitats.
The movement towards low-impact design won't only help prevent flooding and related issues, but it can also keep waterways cleaner and cut maintenance costs. Here's a closer look at all the advantages LID offers.
Reducing Impervious Areas in Design Reduces Stormwater
One of the biggest contributors to community flooding is impervious surfaces, which include roads, buildings, developments, and parking lots. These surfaces cannot absorb water like the natural landscape that they replaced, meaning standing water becomes the norm in rainy conditions.
To manage that standing water, civil engineers install drainage systems to carry water off of impervious surfaces and into designated areas like rivers, ponds, and lakes. The issue is that, with so much water being re-directed into drainage systems in times of heavy rainfall, they often reach capacity and flood. Along the way, the drainage system itself can become blocked or clogged, leading to flooding in the exact areas the system was trying to keep dry, like neighborhood streets.
Through the decades, explosive growth — especially in urban areas like Atlanta and Los Angeles — has demonstrated how the replacement of natural landscape with impervious areas leads to more flooding events. However, it's becoming clear that the answer is not a more robust drainage system, like the L.A. "river," but rather a shift in engineering and design methodology that helps maintain landscapes that drain naturally.
The equation is simple: By reducing the impervious areas in a community, and thereby maintaining more landscape that can drain itself, communities will have less stormwater to manage overall. Beyond simplicity, this results in reduced costs, less flooding, and even cleaner waterways. After all, when the landscape is able to absorb rainfall at the source, rather than directing it through drains where water becomes polluted with debris, community water remains cleaner.
Disconnected Impervious Areas Reduce Management Costs
In today's world, it's hard to imagine a community with no impervious areas. After all, the mere presence of buildings leads to the creation of impervious areas, and safe roadways take priority over reducing stormwater. Still, it is possible to reduce management costs by not only trying to reduce impervious surface area overall but by being mindful of their placement through distributed infrastructure.
For example, rather than a sprawling cityscape of uninterrupted parking lots, the combination of distributed infrastructure and low-impact design encourages disconnected impervious areas that maintain the landscape in between to enable some natural drainage. The implementation of planned landscaping, especially in and around housing developments, can serve a similar purpose.
Once city leaders, managers, and planners connect, civil engineers can get them thinking about how the preservation of natural landscape can support drainage systems (and vice versa), and low-impact design becomes much more achievable.
Low-Impact Design Improves Ecosystems
Low-impact design has benefits that go far beyond stormwater management. The preservation of green space provides air purification, species habitat, and gathering places for citizens. LID also creates a cycle of savings, freeing up more capital to be invested in other areas of the city.
With simpler drainage systems and fewer adverse events (i.e., floods), the money a town saves in maintenance can be re-directed to meaningful projects like parks and recreation improvements, outreach programs, and new infrastructure for schools and businesses.
Achieving Low-Impact Design in Communities
With all the benefits of low-impact design in mind, it's clear that this is the direction the EPA and other agencies are encouraging developers and civil engineers to take. However, that doesn't mean change will come easily.
In reality, implementing low-impact design practices is easiest in new developments and, while this can begin at the neighborhood scale, the small towns across the United States that are experiencing explosive growth are the most likely to implement them. For these communities, proactively leveraging low-impact design as their towns grow into suburbs and cities is the smartest path forward.
For existing urban areas, change will be harder. Retrofitting neighborhoods to incorporate low-impact design isn't easy, but it is possible. As communities continue to grow and develop, low-impact design principles are expected to make their way into standard practices, but it's going to take a collaboration of civil engineers, planners, and local directors for to achieve the most effective results.
As the EPA suggests, now is the time for stormwater agencies to get in touch with their local parks agencies and work together to find a way forward in implementing low-impact design, especially in areas where so much development is set to take place. With best practices laid out, low-impact design has the potential to build better, safer, and cleaner communities.
Engineering Surveys & Services has helped countless communities on their quest to implement low-impact design throughout emerging developments, old neighborhoods, and bustling business districts. If you would like more information on implementing low-impact design, we can help. Reach out to us today and take the first step toward being a LID community!
Short Title: Reducing Stormwater Management Costs
Teaser: Learn how low-impact design can reduce stormwater management costs.
Summary: Rainfall, snowmelt, and torrential weather all lead to an abundance of water. In natural areas, this water would be absorbed into the ground and gradually dispersed over foliage, but in communities where roadways, sidewalks, homes, and other structures persist, this water has to go somewhere else. As a result, developers are re-thinking stormwater management to reduce costs and improve outcomes.
Image Credits: Unsplash @ Creative Commons