By: Brock Storrusten
Managing storm water runoff is a significant issue in any residential, commercial or industrial development. It’s a concern for the community, developer and local and federal governments – and with good reason.
Storm water runoff, if not addressed with development, can have serious consequences, including flooding, erosion, sedimentation and contamination of lakes, rivers and reservoirs.
An evolving landscape with more complexity
As we continue to add more roads, parking lots and building rooftops that are impervious to rain water we would see more runoff, with higher flows and with more velocity unless the effects are mitigated.
Excess storm water runoff has long been a problem, and the practices used to manage have evolved over time. While the main objective historically has been to control, move and contain it, in more recent years, there’s been concern about not just the quantity of water, but the quality as well. Laws have been put into place and local, state and national entities are more involved in finance and management decisions concerning storm water.
While managing runoff is still a primary concern, current thinking about storm water management also reflects a more comprehensive, holistic mindset that not only takes into consideration the above, but also includes environmental mitigation, preservation and incorporation.
One widely used management practice continues to be storm water ponds, a structure that while it protects against flooding and improves water quality, is often misunderstood, and their use should be advocated creatively.
There are basically three types:
- Retention ponds, also called storm water ponds, wet retention ponds or wet extended detention ponds. It’s basically a storm water storage facility with a permanent, pool and is designed to allow sediments and pollutants to settle out of the water.
- Detention ponds, also called dry ponds, which temporarily store water and eventually empty out to streams. They have reduced settling capacity than retention ponds.
- Infiltration ponds, which direct storm water to groundwater through permeable soils. They have the greatest sediment removal since there is no surface outlet and may have landscaping features like rain gardens that assist in sediment removal.
Benefits of storm water ponds
A well-planned, well-designed pond is engineered to mitigate flood surges and reduce pollutants, but it should be designed to do a whole lot more. To do so requires considering water quality, water level and bounce, event frequency, inlets/outlets, plantings and aesthetics, side slopes and drainage and erosion control.
Properly designed, landscaped and maintained ponds provide residents with an attractive water feature that can be used for recreation and add property value. Amenities can include waterfalls, beaches, docks, paths, bridges and parks. Ponds should also serve as a natural habitat for plants and wildlife and should be incorporated into the surrounding environments that they serve.
Misconception #1: They’re a haven for mosquitoes.
Reality: Avoiding shallow water areas will greatly reduce the proliferation of mosquitoes. We also create water movement with bubbler systems, waterfalls and increased fetches in our designs.
Misconception #2: They’re full of bacteria and algae.
Reality: We incorporate bubbler systems which keeps algae and bacteria to a minimum. In addition, putting the right type of plants on the shoreline will filter contaminants that come in through the storm water system. Further, other filtration systems are incredibly beneficial, but aren’t common in North Dakota simply because there are no water quality standards as of yet.
Misconception #3: They’re dangerous for pets and people.
Reality: Storm water ponds will behave similar to a natural lake if they are implemented correctly. People understand and respect lakes, their elevation swings and the varying water levels, so if we incorporate storm water ponds into the environment in a similar way, people know what to expect. To further foster safety, we design shorelines with benches so people have an expectation of depth and to keep the shoreline shallower as with a natural lake.
We also design these with water level fluctuation in mind, knowing that we want to avoid excessive depth or a pond that fills or rises dramatically in a short period of time.
An amenity, not just part of Infrastructure
These are examples of what ponds can be, if they are properly planned, designed, executed and maintained, with clearly defined expectations. And if we start thinking about storm water ponds not as a necessary part of infrastructure and a hazard, but as an environmental feature that can be integrated into the natural habitat to improve our communities and quality of life.
Does this sound like the future you want for your community? Let’s talk.