Storm Water Management

One of the areas where Cascade Meadow Wetlands & Environmental Science Center is focusing its water education efforts is in storm water management.

So what is storm water?

Storm water typically comes from rain or snowmelt that runs off buildings, streets, and other hard impervious surfaces where it does not soak into the ground. Storm water can also come from human uses such as washing cars or over-watering lawns. In some areas storm water is directed into storm drains, through underground storm sewers, and into storm water treatment devices like ponds or raingardens. In other areas, storm water flows directly to a neighboring waterway. If not intentionally managed, urban growth increases the amount and flow rate of storm water and reduces water quality. During large rain events, the large volume of storm water running off impervious surfaces can overwhelm storm drains and cause flooding. Another concern is the potential contaminants contained in storm water. In fact, the U.S. Environmental Protection Agency has identified untreated storm water as the biggest threat to our nation’s water quality. Luckily, effectively managing these storm water issues can have a large positive impact on water quality, aquatic habitats, and our way of life.

Our Best Practices

Cascade Meadow aims to showcase many of the best practices in storm water management. These include:

  • Pervious pavements: the areas surrounding the building utilize several pavements that are designed to increase infiltration of storm water and decrease or eliminate storm water run-off. Pervious pavers are installed with gaps between them and pervious layers of gravel and sand beneath them to encourage quick absorption of storm water into the ground. Pervious concrete is mixed with larger-than-usual gravel that makes for gaps throughout the slab through which storm water can flow to the carefully chosen gravels and sands beneath.
  • Landscape shapes: these are called “bioswales” and “biocells,” which are both landscape shaping techniques that are engineered with under drain systems to increase the chance that storm water will be absorbed into the ground before it reaches a storm water pipe system. The biocells and bioswales at Cascade Meadow have been seeded with a special mixture of native plants chosen for their ability to thrive in the unique conditions of a biocell or bioswale.
  • Treatment Ponds: ponds are engineered to manage storm water flows from large drainage areas. The two treatment ponds closest to the Science Center capture and treat water from about 400 acres of land before releasing the water to Cascade Meadow Wetlands and Cascade Creek. The heavy particles and pollutants attached to them settle to the bottom of the pond. Sunlight and aeration stimulate chemical reactions that treat dissolved pollutants and aquatic plants absorb some pollutants. Water evaporates from the pond and transpire from the plants to reduce the amount of water discharged. This is especially important for the wetlands, which are sensitive to extreme or frequent water level fluctuations.
  • Infiltration Terraces: much of the rainwater that strikes the unique roof of the building will flow into one of two specially designed infiltration terraces, which include rocks, stone slabs and specially designed layers of rock and sand. Water that enters the terraces will be quickly absorbed into the ground.
  • Green Roof: Cascade Meadow also has two areas of “green roof” made of a special mix of plants. Rain water that strikes these areas is absorbed by the plants. Any water that is not used by them flows off the roof more slowly- cleaner and cooler than if it had flowed off a roof made of standard material. Excess water flows from the storm water pipe system into a biocell, and is filtered and treated by the plants and soil organisms before it is absorbed into the groundwater system.

When you come to visit, be sure to check out our interactive storm water exhibits inside the building. 

Take a little time to walk the outdoor “Storm Water Trail,” which highlights the storm water best management practices around the building.

Storm Water Resources

The Minnesota Pollution Control Agency (MPCA) advocates for the use of the storm water management technique called “low-impact development” (LID). Read more about LID and access MN resources for LID at the MPCA website here.

Check out this “Urban Design Tools” site to learn more about design strategies for storm water management, and to see design suggestions and specifications for rain barrels, permeable pavers, and more.

For those of you from the Rochester, MN area, the city storm water management website has information and resources for citizens and businesses including events, permits and more.