Retention ponds and detention ponds have been established as a regular part of our modern landscape in housing communities, neighborhood parks, and commercial landscapes. These ponds are historically surrounded with various types of decorative rock, or manicured turf right down to the water’s edge. While this may have looked attractive at the time that the pond was installed, over the years the aesthetic value of the pond can change drastically. Due to a variety of natural occurrences, shorelines will begin to degrade and can cost thousands of dollars to repair and maintain. There is an alternative, vegetative option available that will help stabilize soils, add texture and beauty to the shoreline, improve water quality, and even discourage water fowl from “fowling” the landscape.

Further, the variety of benefits provided by native vegetation can last a lifetime with a little regular maintenance.

One of the more important benefits of native grasses is that they have extensive root systems that are capable of securing soils in the presence of moving water. Where turf grass roots only occupy the top 2 inches of the soil, native grasses can send their roots down over 2 feet into black dirt and clay.

Another problem with turf grass is that repeated cutting causes the roots to grow very dense and inhibit water from penetrating deeper than an inch or two past the surface. Once this shallow root zone is saturated, the lawn will act much like a paved surface, where the excess water will run off instead of being taken deeper into the soil. This excess surface run off will naturally find its way into the nearest drain or ditch which frequently transfers it into a pond. When native vegetation is established around the shoreline and up the slopes (buffer zone) of such a water feature, the native vegetation can provide benefits such as slowing the velocity of the run off, which helps remove nutrients before they enter the pond. The benefit to water quality is realized because the deep penetrating roots will allow water to more easily infiltrate the soil and slow the flow as it makes its way into the pond. Except during major rain events, this will mean less gulley erosion, as well as cooler water entering the pond which will benefit plant and animal life.

An additional benefit is that while the water infiltrates the soil, the root systems of the native plants remove much of the nutrients that are in the water. Lowering these nutrient levels in this way will help decrease the amount of algae that will grow in a pond, while increasing the oxygen levels for the fish.

Of increasing importance, especially in urban areas, is the effect of native grasses on water fowl, which in great numbers tend to create quite a mess on the landscape. A vegetative buffer around a pond is very effective at discouraging geese for instance from moving from the pond onto surrounding lawns where their droppings create problems. The natural predators of the goose are animals such as bobcat, coyote and wolf. The geese are fearful of the tall vegetation because they think that a predator may be lurking in the tall grasses, so they stay in the water.

As their roots hold soil in place, the native vegetation protects shorelines from waves created from wind, boats, fountains and bubblers. Over time, the energy created by even minute waves will slowly wash out soil from under the turf grass. This is evident on many ponds where the turf grass and soil has “slumped” into the pond and exposes a more-vertical shelf of soil which is prone to further erosion. Not only is this unsightly, but it contributes to the sedimentation of the pond and reduce its capacity to hold stormwater. A pond with less sedimentation will have to be dredged much less often.

Dredging is a very expensive process and many budgets would like to see it done as little as possible.

By establishing a barrier of native aquatic plants in the water, the energy of the waves can be reduced before it reaches the shoreline, further reducing erosion. This water-borne vegetation will also add a lot of texture and color to the shoreline, and offer great habitat structures for many varieties of fish.

Though decorative stone can provide many of the same benefits as a naturalized shoreline, it does have a few draw backs. First and foremost is that the rock will have to be replaced or replenished every 10 to 15 years. As the shoreline ages, the combination of water, waves and gravity will naturally slide the rocks down into the water. Over time this can become very unsightly, and the only remediation is to add more rock to the shoreline. Without the addition of more rocks, waves over time will cause the shoreline to erode. As the rocks settle into the sediment, they provide a good planting medium for invasive weeds, which will have to be controlled to maintain the aesthetic look many desire. This upkeep, along with replenishing the rocks every 10 to 15 years can make these shorelines very expensive to maintain.

Natural shorelines can be installed for a range of prices depending on the types and quantity of vegetation chosen. Maintenance is also required for successful establishment, but to a reduced degree over time. This maintenance is often referred to as stewardship, which may involve a variety of activities such as hand weeding, herbicide application, mowing, enhancement seeding and prescription burning. Though these areas require less effort once established, they should not be neglected, or exotic and invasive species can establish themselves and reduce the functionality of the shoreline. Such aggressive weeds as cattails, purple loosestrife, common reed, thistle and reed canary grass will readily out-compete the native vegetation and occupy the entire shoreline. These species create monocultures of vegetation, and displace the native diversity. With regular stewardship, these native shoreline plantings can last indefinitely and reduce the long term cost of owning a pond.

In addition to the beauty provided by the diverse native flowers and grasses, over time the pond will become a habitat that can attract beneficial wildlife, and enhance the aesthetics and recreational value of the pond. The native vegetation supports a diverse mixture of insects, from dragonflies that eat large quantities of mosquitoes to caterpillars that become colorful butterflies. These are part of a specific diet for many native song birds. By providing such native vegetation, birds benefit by a bounty of seeds, insects, and a much needed structure for nesting and mating.

Birds will not be the only animals to respond, with more insects, there will also be a greater variety of amphibians (frogs and salamanders) and reptiles (turtles). Possibly more noticeable in residential ponds, is the quantity of different fish species that will be able to survive in a naturalized pond. The vegetation will add much needed shelter from the sun, breeding locations, and places to hide for the smaller fish.

Not only can native vegetation stabilize soils around retention and detention ponds, but they add value to a pond by enriching the lives of the people who live around them. The increased plant and animal life can be a focal point for community activities, and perhaps more importantly provide a serene landscape that can be enjoyed by all. SLDT