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Sustainable Stormwater Management

Stormwater ponds collect runoff, trash, sediment, and excess nutrients. Their intended purpose is to reduce the amount of pollutants in the larger watershed by trapping it. They also slow the velocity of stormwater to reduce downstream erosion, and they increase the amount of water that infiltrates back into the water table.

However, if not maintained properly, these stormwater ponds cease to function as designed and put the watershed at risk. Thus far, the pond and lake management industry has lacked organized direction towards sustainability standards. This often leaves communities at a loss. They don’t know if their ponds are healthy or how they can maintain them to be so. The  Clean Water Project's goal is to help fill this gap.

Our rubric for sustainable stormwater ponds serves as a practical guide to keep a pond healthy, functioning, and safe for the community.

Contact us to get your pond assessed or certified as sustainable!

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Functioning Structures

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Healthy Ecosystem

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Safe For The Community

The public health benefit that stormwater ponds provide, as well as the pond’s own ecosystem health, depend on the facility being maintained sustainably. Virginia Waters and Wetlands has partnered with The Clean Water Project to develop industry sustainability guidelines. VWW is an environmental consulting firm with 20 years of experience managing stormwater facilities, with professional environmental scientists and DEQ Certified Stormwater Inspectors on staff.

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Pond Sustainability Guidelines

Why these tasks?

Your stormwater pond will require inspection by a Clean Water Project Pond Inspector. A certification is good for 2 years, and then reinspection is required. At this time, we can only inspect/certify ponds within the DC/MD/VA area.

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  1. Litter Collection: Ponds collect an incredible amount of litter in runoff water, which accumulates on the bottom of the pond and within pond structures. Litter can clog inlets and outfalls, and it can reduce dredging intervals. Pond animals will mistakenly ingest litter, and floating trash serves as breeding grounds for mosquitos.

  2. Aeration: The purpose of aeration is to introduce additional oxygen into the water column and to keep the water circulating. During warm months, ponds will undergo a process called stratification, which is where the water settles into layers divided by temperature. Warm water sits at the top, and cold water sits at the bottom. Because there is little mixing between the layers, the oxygen towards the bottom of the pond gets depleted. These anoxic zones can be deadly to pond plants and animals. Aeration reduces stratification and keeps all parts of the pond well-oxygenated. Aeration can be accomplished with either fountains or weighted bubbler plates called aerators.

  3. Annual inspections: Counties have varying policies on stormwater inspections. Some require them annually already, some require them every 3 years, and some never inspect their facilities. Annual inspections are most beneficial because they catch problems early. Any damaged structures or intrusive woody growth can be caught and remedied before the issue is overwhelming.

  4. Warning signs and/or fence installed: Stormwater ponds can be extremely dangerous to pets, children, or even adults that attempt to wade into them. Any open water poses a drowning hazard to the public. These ponds can be deceiving; there is often a layer of sediment on the bottom of the pond that makes it appear more shallow than it actually is. One can step in, thinking they will be ankle-deep, but then sink through the sediment to much deeper. Ideally the pond is fenced, but we recognize that fences are not possible in every situation. So, we require at least a sign be posted to warn the public of the potential danger.

  5. Maintenance prior to catastrophic failure: Every stormwater facility will eventually require repairs. A pipe will experience joint separation or leaks, the riser will get damaged, the dam may erode… There are a whole host of issues that the facility may experience. If these issues are not remedied in time, the entire pond will cease to function as designed.

  6. When renovations are required to riser/trash rack/psp, upgrade metal to plastic composite: This will not apply to every pond. Some older ponds were built with corrugated metal pipes and metal trash racks before plastic options were developed. Metal structures all eventually rust and leak. Corrugated plastic pipes and trash racks have a much longer lifespan and should be used when possible.

  7. At least a 3-ft buffer that’s mowed once per year: A pond buffer is important to filter sheet flow and prevent erosion around the pond’s edge. It can also help deter geese, and it can be a deterrent for pets or children from trying to enter the pond. While a buffer is beneficial, it does need to be managed so that is does not get too unruly. Mowing once a year, at the end of growing season, prevents woody growth from getting too large.

  8. No fertilizers or mulch used along pond embankment: When fertilizers get washed into ponds, the excess nutrients stimulate algae growth. Large algae blooms then result in anoxic conditions, which can be deadly to fish or other pond animals. Mulch is sometimes treated with herbicides, which can kill native growth. Even if mulch is not chemically treated, its simple volume adds to sedimentation and decreases dredging intervals.

  9. Shoreline plants (cattails, rushes) only removed as needed from structures: Native shoreline plants are beneficial to ponds. They serve as habitat for birds, amphibians, invertebrates, and spawning fish. We recognize that their growth can be aggressive, but they should not be thinned more than what is necessary to keep the pond functioning. This includes removing them from inlets, riser structures, or riprap around the pond.

  10. Install native plantings where possible: When a community takes initiative to add plants to their pond, buffer, or pond embankment, they should use native plants that will be beneficial to the ecosystem.

  11. Use of biological controls (when appropriate): Certain aquatic weeds can be controlled by installing grass carp or tilapia. Bat boxes or purple martin homes can help control mosquitos. Any applicable biological controls should always be put in place before resorting to chemical controls.

  12. Manual removal of algae and duckweed: Raking or using machinery to remove floating algae/duckweed reduces the need for treatment with herbicides. This is desirable because some herbicides can accumulate in the sediment or be toxic to aquatic animals. Manual removal can be labor intensive and expensive, which is why it is only required for a Platinum status.

  13. No copper sulfate used, only Nautique: There is some research to suggest that using copper sulfate to treat algae can be toxic to fish, and using chelated copper has proved safer. Nautique uses a lower amount of chelated copper than other similar algaecides, and one study shows it was two orders of magnitude less toxic than Captain XTR (Wagner et al. 2017).

  14. No glyphosate uses within easement: Glyphosate-based herbicides can be harmful to pollinators like bees. We require that no glyphosate be used within the pond and the entire stormwater easement.

  15. Herbicide sport treatments only when necessary (less than ¼ of pond at once): Sometimes herbicide treatments are unavoidable. Stormwater ponds take in high levels of nutrients, which can result in large algae or weed blooms. Uncontrolled blooms are harmful to the aquatic ecosystem because they deplete dissolved oxygen and contribute to fish kills. Small spot treatments at the beginning of a bloom are safer for the ecosystem then large-scale treatments later on.

How do I get my pond certified?

Your stormwater pond will require inspection by a Clean Water Project Pond Inspector. A certification is good for 2 years, and then reinspection is required. At this time, we can only inspect/certify ponds within the DC/MD/VA area.

Reach Out!

Contact the Clean Water Project today to get more information!

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Virginia Waters and Wetlands

Virginia Waters and Wetlands is our partner organization in sustainable stormwater. VWW can help with stormwater repairs or maintenance. Contact them here: