Stormwater Ponds

What are stormwater ponds?

Stormwater ponds are man-made ponds that mimic natural systems and are designed to collect, store, and treat stormwater.

They are useful for residential, commercial, and industrial areas, but are more effective in larger areas of about 10-20 acres. The ponds are most effective at pollution filtering when they detain water and slowly release it before drying, and when they are planted with native vegetation such as soft stem bulrush, pickerelweed, and sedge.

If there is a stormwater pond in your neighborhood, it can provide many benefits and can also be easily managed and maintained.

To learn what you can do on your own property to filter pollution and reduce runoff, consider rain gardens, which also help the Olentangy River’s habitat.

Wet detention basin

This is a stormwater pond that always contains water and is deeper than a wetland. It is ideal for the greatest water storage and flood control, and is used to store runoff from light to heavy rainfall.

A wet detention basin can include native wildflowers, grasses, emergent plants, and floating/rooted aquatic plants.

Dry detention basin

This is a basin that is flooded only during and shortly after rainfall. It is designed for light to moderate rain.

A dry detention basin can be vegetated with native grasses and wildflowers.

Stormwater wetland

Wetlands are shallow basins with soil that is permanently or seasonally saturated by water. Because they are shallower than wet detention basins, they require more surface area to store the same volume of water.

Wetlands provide the most diverse habitat and consequently the widest range of wildlife. They should include plenty of native wetland plants, which can tolerate low oxygen in the soil.

What are the benefits?

Prevent fertilizer and other pollutants from flowing directly into streams and rivers
Provide flood control
Aesthetically pleasing
Increase property values
Provide recreation
Provide wildlife habitat

Rain runs off hard surfaces such as roads and driveways, herbicides, oil, and other pollutants into local waterways.

However, stormwater ponds and the surrounding vegetation can absorb this runoff and filter the pollution, while also controlling flooding. Ponds can also provide a beautiful habitat for recreation and local wildlife.

How to manage your stormwater pond

Litter removal

Keep the area in and around the pond is free of litter.

Mowing

If you have not left a vegetated prairie area around the pond, mow the grass on the banks at least twice per growing season, and cut the grass no shorter than 6 inches.

Keep woody vegetation 30 feet away from the spillway structure and 15 feet away from the embankment.

Fertilizers

Do not over-fertilize lawns around the pond. Excess fertilizer can run into the pond during storms and cause plant or algae growth.

Vegetation

Stormwater ponds are most effective with native plants around the edge and bottom.

Native vegetation helps increase the pond’s capacity.
Vegetation protects slopes from erosion.
Slopes and shorelines can be planted with native wetland perennials.
Vegetation that grows in water but sticks out into the air discourages geese and controls algae. Shallow areas – 6 inches to 12 inches – just inside the edge the pond, is ideal for this.
Check for invasive plants semi-annually.
Replant any bare areas around the pond quickly so they do not erode.

Buffer Zone

Create an unmowed vegetated area of at least 10 feet around the pond to prevent erosion and increase pollution uptake. Alert your lawn care provider about this.

See Tables 1.1 and 1.2 below

For additional information, see http://ohiodnr.gov/portals/0/pdfs/invasives/Wetland-plants.pdf

Wildlife, stormwater basins, and wetlands

Properly designed stormwater basins and wetlands contain the water and nutrients necessary for a highly productive system.

Native plants are the key to attracting a diversity of wildlife. Native plants provide the best habitat for waterfowl, small mammals, fish, frogs, turtles, songbirds, and pollinating insects.

The lush vegetation can attract:

Mallard duck
American black duck
Canada goose
Belted kingfisher
Red-winged blackbird
Gadwall
Snapping turtle
American painted turtle
Eastern-tailed blue butterfly
American painted lady butterfly
American viceroy butterfly
Bullfrog
Green frog
Common yellowthroat

This can provide:

Recreational opportunities including bird watching, fishing, and picnicking
Relaxation while listening to the natural sounds of insects, birds, and frogs
Satisfaction of providing habitat for sensitive and threatened species
Improved mosquito control

After the first year, an initial inspection should be done to ensure the survival of at least 50% planted species and the absence of invasive plants.

-Do not inspect until 2-3 days after a large rainfall event

At least four times a year and after major storms:

ØLeave a marker in permanent pools to inspect for prolonged periods of high water. If there are prolonged periods (more than 3 days), there may be a clog at the inlet or outlet structures. Debris removal does not require a professional.

Prolonged low flow could mean leaks.

Leaks in upstream dams, pipes, and risers require repairs by specialized contractors, and leaks in downstream dam faces and vortexing require an engineering consultant.

Check for floating debris and undesirable vegetation.
Investigate the shoreline for erosion.
Look for safety hazards (e.g. broken signs and locks).

Semi-annual to annual:

Check to make sure mechanical components are functional
Identify invasive plants

Every 1 to 3 years

Inspect riser, barrel, and embankment for damage
Inspect pipes
Monitor sediment deposition in structure and forebay

Every 5 to 25 years

Remote television inspection of hard-to-access pipes

Undesirable Vegetation

Monocultures and invasive plant species can inhibit the growth of other native plants and decrease the performance of the stormwater pond.

Monocultures can be removed by hand, but invasive plants may require herbicide applications. Be sure to read all herbicide instructions and apply with care.

Common invasive plants to stormwater ponds include purple loosestrife (Lythrum salicaria), multiflora rose (Rosa multiflora), and common reed (Phragmites australis).

Trees and woody plants with extensive root systems should be removed from slopes and embankments.

You can then replant with a variety of native species.

Clogs

Many clogs can be removed by hand or machine. Some pipes can be flushed or jetted with high velocity spray devices. Contact a qualified contractor if dredging is needed.

Safety

Be careful working around the water’s edge, and leave the high maintenance work to professionals. Non-professionals should only attempt vegetation, clog, and minor wildlife nuisance maintenance.

A rain garden is a shallow depression that collects stormwater runoff and is planted with native vegetation and grasses.

Benefits

A rain gardens provides an attractive addition to any yard while also preventing flooding, decreasing water pollution, and creating habitat.

Stormwater runs off of driveways, roads, and roofs and collects pollutants. It goes into local rivers, streams, and, in some areas, storm sewers.

Rain gardens prevent these pollutants from contaminating the water by intercepting the water and naturally cleaning it.

More Information

If you would like to create a beautiful and useful rain garden on your property, please visit http://www.centralohioraingardens.org/ for more information.

To help keep the Olentangy River healthy and clean:

Only apply fertilizers and pesticides when and where needed and avoid paved surfaces that drain into storm sewer.
Clean up oil and other vehicle fluid spills and leaks, and store oil, gasoline and antifreeze properly.
Wash vehicles at a car wash or on a non-paved surface to avoid runoff into storm sewer.
Don’t allow pet waste to be washed into the sewer.
Keep grass clippings and leaves from washing into the sewer.
Position downspouts to drain onto grassy areas.
Collect water from downspouts into rain barrels for use around the house.
Prevent bare soil from eroding into storm sewers by mulching and seeding as soon as possible.

Austin, M. R. (1996). Ohio pond management handbook: a guide to managing ponds for fishing and attracting wildlife. Columbus: Ohio Dept. of Natural Resources, Division of Wildllife.

Central Ohio Rain Garden Initiative. (n.d.). Retrieved from http://www.centralohioraingardens.org/.

Department of Public Utilities, Division of Sewage and Drainage. (2006). Columbus Stormwater Drainage Manual. Columbus, Ohio: Department of Public Utilities.

Lazur, A., Hengst, A., Markin, E., Webster, D., Billing, K., Schuck, D., & Buritsch, H. (n.d.). Urban and Stormwater Pond Management [Pamphlet]. Cambridge, Maryland: University of Maryland.

Ogle, D. G., & Hoag, J. C. (2000). Stormwater Plant Materials: A Resource Guide. City of Boise, Public Works Department, Boise, ID.

Franklin Soil and Water Conservation District. (n.d.). Stormwater Pond Management and Maintenance [Brochure]. Columbus, Ohio.

USEPA. “Green Infrastructure.” Low-Impact Development and Green Infrastructure in the Semi-Arid West. <www.epa.gov/region8/green-infrastructure>.

USEPA. “Soak Up the Rain: Rain Gardens.” <www.epa.gov/soakuptherain/soak-rain-rain-gardens#main-content>.

United States, Environmental Protection Agency. (2009). Stormwater wet pond and wetland management guidebook. Washington, D.C.

United States, Ohio Department of Natural Resources, Division of Natural Areas and Preserves. (2007). Selected Ohio Native Plants for Landscape Restoration and Reuse: Wetland Species. Columbus, Ohio: Ohio Dept. of Natural Resources, Division of Natural Areas & Preserves.

Table 1.1

Common Name	Scientific Name	Habit	Location**	Soil Moisture and/or Water Depth
Pickerel weed	Pontederia cordata	Forb	Bench	About 12″
American water lotus	Nelumbo lutia	Forb	Pond bottom	About 36″
Yellow pond-lily*	Nuphar lutea	Forb	Bench /Pond bottom	12-36″
Long-beaked arrowhead	Sagittaria australis	Forb	Shoreline/Bench	Saturated-12 “
Common arrowhead	Sagittaria latifolia	Forb	Shoreline/Bench	saturated-12″
Blue flag iris	Iris versicolor	Forb	Slope/Shoreline/Bench	Saturated-6″
Swamp milkweed	Asclepius incarnata	Forb	Slope/Shoreline	Moist soil-2″
Buttonbush	Cephalanus occidentalis	Forb	Shoreline/Bench	Saturated-36″
Lanceleaf Frogfruit	Phyla lanceolata	Forb	Shoreline	saturated-4″

Table 1.2

Common Name	Scientific Name	Habit	Location**	Soil Moisture and/or Water Depth
Black-eyed susan	Rudbeckia herta	Forb	Embankment/ Upper slope	Dry-Moist
Spotted Joe Pye weed	Eutrochium maculatum	Forb	Upper slope	Moist soil
Crimson-eyed rose mallow	Hibiscus moscheutos	Forb	Slope/Shoreline	Moist soil-2″
Brown fox sedge	Carex Vulpinoidea	Forb	Shoreline/Bench	Saturated-6″
Allegheny monkeyflower	Mimulus ringens	Forb	Shoreline/Bench	Saturated-6″
American white water lily*	Nymphaea odorata	Forb	Bench/Pond bottom	18-24″
Red-footed spike-rush	Eleocharis erythropada	Graminoid	Shoreline/Bench	Saturated-6″
Blunt spike-rush	Eleocharis obtusa	Graminoid	Shoreline/Bench	Saturated-6″
Broad-leaved cattail*	Typha latifolia	Graminoid	Shoreline/Bench	Saturated-12″
Sweet flag	Acorus americanus	Graminoid	Shoreline/Bench	Saturated-12″