Retention 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 appear attractive at the time of installation, over time the aesthetic value of the pond may change drastically. Due to a variety of natural occurrences, these shorelines will begin to degrade and can cost thousands of dollars to repair and maintain. Native vegetation is an alternative option that will help stabilize soils, add texture and beauty to the shoreline, improve water quality and create a diverse habitat for insects, birds, and animals.
Benefits for All
An important characteristic of native grasses is the extensive root systems, which 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 extend their roots down over 2 feet into black dirt and clay. One problem with turf grass is that repeated cutting causes the roots to grow very dense, thereby inhibiting water from penetrating deeper than an inch or two past the surface. Once the shallow root zone is saturated, the lawn acts much like a paved surface, where the excess water runs over the surface instead of being taken deeper into the soil. This excess “run off” naturally finds its way into the nearest drain/ditch, which commonly ends up in a pond.
When native vegetation is established around the shoreline and up the slopes (buffer zone) of the pond, the velocity of water decreases as it approaches the pond, removing nutrients before the water enters. The deep roots allow water to more easily infiltrate the soil in the buffer zone, and slowly make its way to the pond. By reducing the amount of water flowing over the land – except during major rain events – there is less gulley erosion and cooler water in the pond, which benefits much of the plant and animal life.
Native vegetation also protects the shoreline from waves created by wind, boats, fountains and bubblers. Over time, the energy created by waves slowly pulls soil out from under the turf grass. This is evident in many ponds where the turf grass and soil has “slumped” into the pond, leaving behind a vertical shelf of soil prone to further erosion. Not only is this unsightly, but it contributes to sedimentation of the pond which reduces its holding capacity and leads to increased dredging. A barrier of native aquatic plants intercepts the waves’ energy before it reaches the shoreline.
In addition to adding a range of textures and colors to the shoreline, over time, native plant shorelines provide great habitat structures for a variety of insects, fish, birds, reptiles and other animals. Dragonflies help control the mosquito population and caterpillars blossom into beautiful butterflies. Songbirds, attracted to the insects and native seeds, create a living and mating habitat. One might be lucky enough to attract a hummingbird with some common native flowers such as Wild Bergamot, Cardinal Flower, Great Blue Lobelia, Beards Tongue, or Trumpet Creeper. Frogs, salamanders, and turtles enjoy the diverse plant and insects and the number of fish species increase as the vegetation provides shelter from the sun, breeding locations, and hiding places for smaller fish.
Installation and Maintenance
Natural shorelines can be installed for a range of prices depending on the types and quantity of vegetation chosen. In order to ensure the success of the planting, regular maintenance – or stewardship – should be conducted. Stewardship involves activities such as hand weeding, herbicide application, mowing, enhancement seeding and prescription burning. It is important to conduct maintenance activities until the native plants are fully established. If neglected in the early stages, exotic and invasive species can takeover, thereby reducing the functionality of the shoreline. Aggressive invasive weeds such as cattails, purple loosestrife, common reed, thistle and reed canary grass are common threats. These species create monocultures of vegetation, and displace the native diversity. With regular stewardship, the native plants can last indefinitely and reduce the long-term cost of owning a pond.
Native vegetation stabilizes the soils around retention and detention ponds to create a more sound – and ecologically diverse – shoreline, but it also adds value by enriching the lives of the people who live nearby. The increased plant and animal life creates outdoor community activities such as fishing for adults and frog hunting for kids. And indeed, a person walking by on a nice evening would enjoy the serene landscape complete with songbirds and butterflies.
By: Acri Community Realty