Stormwater Management – What it Is, How it Works, and Why it’s Important
What is stormwater?
Stormwater is water from rain, melted snow and melted ice. It often absorbs into the soil, evaporates into the atmosphere, travels across impervious surfaces into the city’s network of stormwater collection systems (inlets and pipes), or it may run off into a nearby body of water like a lake, stream, or the ocean.
What is Stormwater Management?
Stormwater management refers to the process of helping to control, collect, guide, and use stormwater runoff and to improve water quality. Stormwater management involves several different components of the process, from planning to maintenance, execution and regulation.
Why is Stormwater Management Important?
In undeveloped areas, nature takes its course and stormwater evaporates, sinks into the ground, or finds its way to bodies of water, but in urban and developed areas where the natural landscape has been disrupted by construction, buildings create a significant amount of runoff without the ability for it to find a safe place to go. When we develop land, we disrupt the natural landscape and this can cause unwanted consequences with water quality and safety. Stormwater runoff can draw pollution or contaminants into human water supplies, and stormwater issues like flooding can be catastrophic to homes and businesses. Being able to manage both contamination and water flow is essential to safety for humans and our surrounding environment.
What are the Goals of Stormwater Management?
Effective stormwater management accomplishes several goals, including the following as outlined by the University of Nebraska-Lincoln Extension Institute of Agriculture and Natural Resources:
- Protecting the environment
- Protecting people and property by reducing flooding
- Reducing the demand on public stormwater drainage systems
- Supporting healthy streams and rivers
- And creating healthier, more sustainable communities
What are some Stormwater Management examples?
Stormwater management is evolving from more conventional stormwater management methods (also known as gray infrastructure) like gutters, storm drains, and pipes, to more sustainable practices. Here are just a few examples of stormwater management components:
- Vegetated swales – These drainage paths transport water and help to slow runoff while filtering pollutants.
- Green roofing – Green roofs provide an aesthetically pleasing and eco-friendly way to collect and make use of rainwater, mitigate atmospheric pollution and help reduce energy costs.
- Permeable paving – Unlike impermeable paving materials like asphalt, permeable paving solutions allow for water to trickle through a porous surface into the soil and groundwater. Permeable paving materials include pervious concrete, porous asphalt, and grid pavers.
- Sand and organic filters – These filters can help to remove pollutants from groundwater on its journey to groundwater for reuse.
- Riparian buffers – These are boundaries along shorelines, wetlands or streams where development is either prohibited or restricted, helping to protect the natural aquatic environment from human impact.
- Bioretention areas – known as rain gardens on a smaller scale, bioretention areas help guide runoff to a pond in a designated area and filter through soil and vegetation.
- Stormwater storage – water may be collected and stored using stormwater management components like retention ponds and other rainwater harvesting systems.
- Constructed wetlands – these man-made environments are created to mimic natural habitats and help to slow stormwater runoff, and filter and absorb stormwater.
- Water quality monitoring systems – water quality is a major component of stormwater management. Monitoring systems measure things like pH, conductivity, and temperature, among others.
What are the Benefits of Stormwater Management?
Effective and sustainable stormwater management planning offers a number of benefits:
Improved water quality
Proper filtration and stormwater management practices help to ensure that debris, chemicals, and other pollution or contaminants are kept out of the water supply.
Flood prevention and reduction
By controlling both the flow and the volume of runoff, stormwater management systems can help reduce the risk of flooding in rural and urban areas.
Erosion prevention
Erosion is another issue that improperly managed stormwater can cause, leading to unsafe conditions as well as destruction (or even collapse) of property. Erosion can also cause sediment buildup in the water which can cause obstructions and negatively impact both water quality and local habitats. Proper stormwater management can help prevent these issues.
Avoiding sewage overflow
Heavy precipitation can lead to sewer system overflow, creating a risk to public health and the environment. By controlling the water volume, stormwater management systems can help prevent this from happening.
Preventing damage to property and infrastructure
Improperly managed stormwater can cause devastating damage to roads, commercial buildings, bridges, homes, and other manmade structures.
Groundwater recharge
Stormwater management systems help allow water to seep back into the ground instead of sitting on the surface and turning into a flood or evaporating and being unusable. For urban areas that can face water supply shortages, this is especially important as groundwater recharge can help sustain a safe water supply.
Biodiversity protection and preservation
Human development can be disruptive to natural aquatic habitats. Proper stormwater management can help protect and support local bodies of water and wetlands by preventing pollution and other disruptions from reaching these habitats.
Enhanced community wellbeing
When stormwater is managed properly, the whole community benefits. This can look like more usable green space for recreation, improved aesthetics through appealing sustainable stormwater management practices like green roofing, an increase in sustainability-focused construction and design jobs, and increased property values.
How does Stormwater Management Work?
Stormwater management strategies vary based on the natural landscape and the needs of each unique project, but here are some more standard steps for best stormwater management practices:
1. Assessment
To determine the proper stormwater management protocols for the project, a site analysis is conducted to look at things like topography, existing infrastructure, drainage patterns, soil composition, and other components that impact the volume and flow of stormwater runoff.
2. Planning
In this phase, project managers establish stormwater best management practices (BMPs) including structural (physical components of stormwater management systems) and non-structural (land use planning, pollution prevention programs, etc.) and create a plan.
There are two major types of stormwater management plans – a Stormwater Pollution Prevention Plan (SWPPP) and a Stormwater Management Plan (SMP). A Stormwater Pollution Prevention Plan is a shorter-term solution that addresses management and mitigation of pollution in stormwater runoff during the construction phase of a project. A Stormwater Management Plan is a longer-term solution that details how stormwater runoff will be managed over time after a project is completed. This explores considerations like flood risk, water quality, erosion control, and emergency protocols.
3. Execution
During this phase of stormwater management, the plans are put into practice and physical structures and non-structural components are implemented.
4. Maintenance
Continued periodic maintenance is crucial for implemented stormwater management systems to remain effective. From clearing built-up debris in drainage systems to trimming overgrowth in rain gardens and constructed wetlands, stormwater management systems require monitoring and upkeep in order to continue to prevent flooding, pollution, and erosion.
Regulations and compliance
There are rules and regulations that stormwater management plans need to follow in order to be able to move forward. Once implemented, inspections will occur to ensure proper maintenance and compliance.
Are there any Drawbacks to Stormwater Management?
As with any construction project, there is a risk of certain issues with stormwater management, but these are largely due to improper maintenance, incorrect planning, or not adhering to regulation and compliance guidelines. If a stormwater management system experiences an obstruction or other failure, for example, this can lead to unwanted flooding, erosion, or water being moved where it shouldn’t. If rules and regulations aren’t followed around things like fencing or other structural requirements, it can leave organizations vulnerable to litigation if someone gets hurt.
Overall, with proper planning and regular maintenance, stormwater management are invaluable assets to individual properties and their larger communities, helping to keep people safe while helping the environment in the process.
Making Your Stormwater Management Project a Success
When it comes to planning a stormwater management project, there are a lot of moving parts that need to be navigated in order to ensure the project will be successful and will be allowed to move forward from a regulatory standpoint. This requires excellent communication, and securing a team of professionals that have experience navigating complex permitting, planning, environmental and finance concerns.
At Eberly & Associates, our team of professional civil engineers, land planners, and landscape architects are used to even the most complex development projects and have been helping our clients build and execute effective stormwater management plans in Atlanta and beyond for over 40 years. Our cross-functional team will work with you to help create sustainable solutions that keep communities and properties safe.
Contact us today to learn more about our team and how we may be able to help with your next stormwater management project!
Featured Stormwater Management Projects in Atlanta & Beyond
The Brunswick
The Brunswick is a live/work community located adjacent to Lillian Webb Park. Our team designed a system that also managed the stormwater for the adjacent City/County Library in Norcross, GA. Learn more about this stormwater management project for The Brunswick.
The Georgia Institute of Technology Campus Center
Eberly & Associates is providing Civil Engineering services for the Campus Center Renovation and Expansion at Georgia Institute of Technology. The project involves sustainability initiatives like rainwater harvesting and expanded site utilization for student interface for the new Campus Center. Learn more about this stormwater management project for the Georgia Institute of Technology.