5 Stormwater Management Solutions
The best way you can control your stormwater runoff is by implementing Best Management Practices (BMPs).
Whether you have them in place to meet permit requirements or for simply reducing the overall effects of stormwater runoff from your facility grounds, below you will find our five expert solutions to manage your stormwater runoff.
Dry detention basins, also known as dry ponds, are stormwater solutions designed to contain water for a short amount of time while releasing it away slowly. In addition, the basins help purify the water.
For example, during and immediately following storm events, the basin becomes filled with runoff water, and its short stay in the pond lets particles and pollutants settle to the bottom. Then, the outlet structure slowly releases the water into a sewer system when it reaches a certain level.
During significant storm events, emergency spillways carry the water away from the basin. However, it’s best practice to monitor this action due to the risk of erosion.
These basins are a great asset when managing stormwater, mainly due to their ability to be sustainable in any U.S. climate or region. However, one limitation you may notice is the amount of space needed to construct one.
If your facility space turns out to be too small, the outlet system can become faulty due to constant clogging during storm-related weather events.
The EPA [Environmental Protection Agency] recommends having a minimum of about 10 acres to construct one. Additionally, you shouldn’t install one alone in areas prone to highly contaminated runoff, otherwise known as “stormwater hot spots.”
Nevertheless, dry detention basins are among the best flood control systems for stormwater.
Artificial Lakes & Ponds
Retention basins are artificial lakes and ponds which treat stormwater runoff by mimicking natural watersheds. The excess water then undergoes a natural treatment process.
For example, sedimentation allows the removal of particles, organic matter, and metals, while biological elements—plants, algae, and bacteria—work to remove pollutants. They hold a constant water level, unlike dry ponds, and only release the water to receive more after a storm.
Although retention basins can be used in almost any application and easily retrofitted for existing detention basins, they require special care. They’re not suitable for every location, and you’ll probably have to pay a hefty upfront cost.
In addition, it’s not wise to build these basins in permeable soil since the water would pass through, decreasing the water level. Also, these basins require periodic inspection due to the surrounding vegetation and for routine maintenance.
Before even building the basin, you also have to consider the potential disturbance it may cause to surrounding wetland areas and how it may contaminate groundwater because any design flaw can decrease your water quality.
However, these artificial ponds function as another solution to manage your stormwater and add an aesthetic appeal to your properties. They’re also sustainable (on average more than 20 years) with proper maintenance.
Chamber Filtration System
Sand filters are not only effective stormwater management systems, but they can also effectively remove pollutants from stormwater runoff. They are typically two or three chamber systems.
The first chamber holds the sediment and helps reduce large and heavy residues that float in the water. Additionally, as the water filters through the sand bed in the second chamber, more pollutants are left behind.
The treated water then passes through the discharge chamber, releasing it into a storm drainage system or directly towards surface water.
You’ll see sand filters in developed urban settings that have water-resistant surfaces, like paved parking lots, garages, and driveways. These systems also act as an additional infiltration option in drier climate regions.
However, they do have less capability to remove nutrients and metal from runoff and typically handle only small areas. In addition, you need regular maintenance to prevent clogging, and you may have to replace the filter matter often.
Another drawback is that sand filters don’t protect against erosion. Still, sand filters do a great job reducing most runoff pollution and help protect groundwater quality. In addition, they take up far less space compared to artificial ponds and detention basins.
Vegetated or grassed swales are shallow, open channels specifically engineered to slow stormwater runoff while also removing pollutants. You can build swales in any area that supports dense vegetation, and they function exceptionally well in residential and industrial sites that maintain a small population with lower than average water flow.
Unfortunately, these swales are not as effective in flat or steep marked areas and cannot withstand high water flow. In addition, since there’s no barrier below the swale, pollutants have a greater potential to reach and contaminate groundwater.
However, these systems can be used alone or with other BMPs and encourage infiltration while reducing overall water flow.
Anything that is stored outside or exposed to rain and runoff should be covered if it has the potential to contaminate stormwater. Coverings can include anything temporary, like plastic, tarp, or something more permanent such as a roof or shed.
Coverings are very common since most facilities house either raw materials, byproducts, or other goods that could pollute stormwater runoff.
Some disadvantages include frequent inspections, and at times, they’re not as effective. However, coverings are extremely easy to apply in many situations and are a cost-effective solution.
These five general stormwater BMPs are only a few ways to keep your runoff under control. Though, we do note that every project and situation requires different methods.
If you have any questions regarding what stormwater BMPs may be best for your current project, connect with your stormwater management partner today.