A traditional method of stormwater management involves diverting water as quickly as possible away from where it falls. In Las Vegas, where it rains only occasionally but heavily, the huge volumes of fast-moving water can be dangerous and destructive.
BTL’s interest and involvement in the stormwater industry has been well established over the years, so we were excited to attend Storm-Con 2014 in Charleston, SC, earlier this summer. Storm-Con brought together stormwater managers, engineers and designers from communities of every size and stage, as well as companies like BTL that provide services and solutions for stormwater management. BTL’s liners & geotextile fabrications play an important role in the function of a well-designed system, and with increasing urbanization and concerns regarding the protection of natural resources, many city, state and federal agencies have projects in progress. BTL attends conferences like Storm-Con in a continuing effort to share our expertise with engineers, designers and procurement professionals in these communities.
What is stormwater?
When it rains, some water is absorbed naturally through surfaces such as grass or other vegetated areas with soil, sand or gravel that will allow the passage of water. These are called pervious surfaces. In developed and urban areas, water often falls on impervious surfaces such as rooftops, sidewalks and streets, and travels over other impervious surfaces as it seeks an absorption point. This water that cannot be naturally absorbed where it falls is called stormwater.
In this stormwater retention system lined by BTL, captured stormwater will go through an oil/water separator. Processed water will then be used as grey water for household and irrigation use.
Why has stormwater management become such a big issue recently?
Stormwater has become an issue in those places in which exposed earth, grass and trees has been replaced with pavement or other impervious cover. The loss of natural areas leads to large volumes of runoff that flow into the nearest storm drains and local waterways. As the water flows across streets, rooftops and even lawns in residential areas, stormwater picks up sediment, oils, chemicals and excess fertilizer. If that water is routed directly to natural waterways without being treated, it can contaminate the ecosystem and damage the quality of local drinking water. Naturally, the more impervious surfaces there are in a city, the more stormwater enters the system. Above all, a city’s infrastructure must be able to manage that volume of stormwater, or the city faces even more immediate problems like dangerous street and basement flooding or even sewer backups.
What is traditional stormwater management?
Traditional management practices usually focus on either diverting stormwater as quickly as possible through underground pipes or culverts directly into a natural body of water, or collecting and retaining it in underground cisterns or large basins. These retention points are watertight systems that reduce the velocity of the stormwater and allow sediment and trash to settle out before it is eventually discharged into the environment or transported through the sewers to a water treatment plant. BTL provides the watertight liners that ensure no water escapes as it travels through the system.
What is “green” stormwater management?
Green stormwater management emphasizes the use of permeable pavements and rain gardens to absorb rainwater in place whenever possible, before it has picked up contaminants. Green infrastructures usually include detention systems, which actively slow down the water and guide it along a specific path, and different types of natural filtration such as gravel, sediment basins and artificial wetlands. These design elements mimic a natural watershed and cleanse the water of contaminants. In these systems, impermeable BTL and RPE liners prevent the escape of water into the environment before it has completed its filtration cycle.
Rain gardens are placed to gather rainwater falling nearby and allow it to naturally seep into the ground, recharging the local water table.
We are enthusiastic about our geotextile products and how they can contribute to the success of well-designed stormwater management systems. Our products lead the industry in reliability, cost-effectiveness, and ease of installation. Whether you are contemplating traditional models of stormwater management or newer systems focused on sustainability and environmental awareness, we can help. Jim Nicholson is a Regional Manager for BTL and one of the most knowledgeable in the country about stormwater storage systems. He can be reached in our Wisconsin office at 920-209-1969. Or call BTL at 541-447-0712 and speak to one of our other stormwater experts!
Underground retention and detention systems like this one in Saitama, Japan, can be engineered to manage the massive amounts of rainfall that come with major typhoons or hurricanes.