Caring for our natural resources, which face increasing pressures from a growing population, requires everyone to help however and wherever possible. One of the best places to begin is right where you live. Whether a narrow open lot or larger woodland, your backyard is part of the community's environment or ecosystem. An expanse of neatly trimmed turf that's pleasing to some is inhospitable to most wildlife, and the practices necessary to maintain such a lawn may contribute to water quality problems. By making different landscaping choices, property owners can do their part to support healthier habitat and cleaner lakes and wetlands. Check out some of the information from the Minnesota Department of Natural Resources that you can implement in your backyard.

What's With My Pond?

You call it your pond because it’s near your home.

But what is it, actually?

Your pond may be a wetland that formed many years before Eagan urbanized. Some wetlands have open water over four feet deep and are Minnesota “public waters.” Others are shallow and full of various plants. But your pond may be among 100s of stormwater basins constructed by land developers. The City required these basins to manage stormwater and protect lake water quality. It can be difficult to distinguish between natural and constructed ponds. Cattails, duckweed, algae, frogs, turtles, and ducks live in both.

Whose pond is it, anyway?

Minnesota Water Law provides authority over surface and underground waters. Your pond’s water is public, even if the land next to or beneath it is private. But the public has no legal right of water access without using public land or having permission to use your property. Drainage and utility easements provide City access to manage the storm drainage system. Most Eagan ponds are part of a complex system that stores and drains stormwater runoff. As necessary, we clear and repair pond inlets and outlets to keep the system functioning. Some ponds receive only runoff from private properties. Management responsibilities are private in these locations.

What about flooding?

Land areas draining to your pond (its watershed) may be several or dozens of acres. Engineers designed our drainage system over 35 years ago to handle most storms. But sometimes runoff volumes and flows are too much. In July 2000, it rained 10-12 inches over two straight nights. More than 200 Eagan homes had significant water damage. Repairs to homes and improvements to reduce flooding exceeded $6 million.

Climate change is causing warmer temperatures in Minnesota than 35 years ago. We also have bigger storms and more runoff. The City is analyzing our drainage system to adapt to climate change.

What about seasons?

Winter’s grip is shorter than 35 years ago, but your pond still freezes. Ice over four inches thick is safe for skiing or skating at your own risk. Snow cover, groundwater, muskrats, and other factors make ice conditions unpredictable. Take precautions and be safe while you enjoy the cold season.

Spring’s thaw comes sooner, causing snowmelt to drain to your pond. Algae and other plants start growing under translucent ice. Frogs, turtles, and aquatic insects emerge to propagate. Ducks, geese, and other animals also may arrive.

Summer’s heat lasts longer than 35 years ago. Weather patterns may extend periods of high-water or drought and stagnation. Algae may blanket your pond or duckweed may cover the surface.

Fall’s transition is shorter, but we welcome cooler temperatures. Diminished day length triggers plants to die, erasing the green from your pond. The clearer water reflects splashes of autumn’s hues and migrating ducks and geese.

What about the plants?

Algae are the natural base of a pond's food chain. Microscopic animals eat the algae and are eaten by small animals. Bigger animals eat smaller animals, and so on. Cattails, duckweed, and submersed plants are also natural and common in our ponds. But urban areas and climate change make a big difference. Impervious surfaces drain snowmelt and rain to ponds. Runoff carries tree litter, yard debris, and pet waste that contain phosphorus. Large, urban watersheds can deliver excessive phosphorus to lakes, causing pollution. Only a little phosphorus can fertilize quick growths of algae. Our warmer, wetter climate may cause aquatic plants to grow quicker and last longer in ponds.

Blue-green algae—less common than other algae—are actually unique bacteria. Sometimes, blue-greens produce harmful toxins for people or pets. You can’t tell if toxins exist without special analyses. People and pets should avoid any contact with surface waters that are blue-green.

What can we do to our pond?

The City manages the storm drainage system for water storage and flow. Please report if plants or other issues are blocking these important functions (cityofeagan.com/request; (651) 675-5200)).

If you dislike your pond’s algae and plants, it may be permissible to net, cut, or pull them, possibly subject to state regulations. You may also be permitted to use chemical herbicides to manage aquatic plants in Minnesota public waters. To be sure, contact the DNR (www.dnr.state.mn.us/shorelandmgmt/apg/permits.html). You may think an aeration system or fountain will control algae or aquatic plants. Yet these devices are not a definitive solution. Often they simply move floating vegetation away from the immediate area. They may foul or clog, requiring regular maintenance. They may stir up pond sediment in shallow water. Residents need a DNR permit for aerators or fountains in Minnesota public waters (www.dnr.state.mn.us/eco/lakeaeration/index.html).

What can we do in our watershed?

Everyone in Eagan contributes to stormwater runoff. What you do around your home affects more than only your property. If you're maintaining the lawn or washing the car, you're impacting the watershed. If your car is leaking oil or you're littering pet waste, you’re polluting ponds.

You can do your part:

  • Maintain a lawn with deep roots and soils that can absorb rainwater.
  • Irrigate as little as necessary; hook-up a soil-moisture sensor.
  • Install a rain barrel to collect rooftop drainage for landscape watering.
  • Have the right plants for your soil type, moisture, and sunlight conditions.
  • Construct a rain garden to collect and absorb runoff.

You can keep these pollutants away from runoff:

  • Leaves and grass clippings,
  • Lawn fertilizers and carwash detergents with phosphorus, and
  • Leaking oil, pet waste, and other pollutants.

You can learn more about what you can do (cityofeagan.com/watersmart).

The storm drainage system works best when:

  • Water drains to and from ponds without obstructions,
  • Pond levels rise and lower for temporary durations, and
  • Inlet and outlet structures are in good condition.

Please report when the system seems to need repair or not to be working (cityofeagan.com/request; (651) 675-5200).

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