Sustainable Land Development Today - November/December 2008 - (Page 38)

EROSION CONTROL Native Grasses: Something to Bank On Trimming stormwater features with native grasses can produce long-term benefits. By Mark Micek 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. 38 November/December 2008 Sustainable Land Development Today

Table of Contents Feed for the Digital Edition of Sustainable Land Development Today - November/December 2008

Sustainable Land Development Today - November/December 2008 Contents Our Voice Editorial Board SLDT Resources The BottomLine Go Forth and Tread Lightly on the Land It’s About Name Recognition Managing Risk in the Sustainable Building Frontier Industry Spotlight Achieving Sustainable Land Development Worthy of Recognition Stormwater Wastewater Erosion Control Innovation Classifieds Advertiser Index Last Word

Sustainable Land Development Today - November/December 2008

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