|Clevenger, Bruce - OHIO STATE UNIVERSITY|
Submitted to: Ohio State University Extension Publication
Publication Type: Other
Publication Acceptance Date: October 3, 2003
Publication Date: January 4, 2004
Citation: Luckeydoo, L.M., Fausey, N.R., Clevenger, B. 2004. Vegetation establishment and management guidelines for constructed basins for agricultural water treatment. Ohio State University Extension Publication. Bulletin 909. p 1-25. Technical Abstract: Treatment basins are water bodies created to collect waters with elevated nutrients, sediment, or other pollutants and improve that water's quality using natural processes. These basins help protect downstream and offsite water quality by temporarily holding floodwaters and reducing potential pollutants these waters may contain before they move offsite. Vegetation aids in many processes that result in improved water quality in such treatment basins. Vegetation helps remove sediments, helps to prevent erosion, removes nutrients from the system by incorporating those nutrients into their tissues, and creates an environment for microbes to further remove nutrients and other pollutants from the water. Since vegetation is such an important part of the water quality improvement benefits of treatment basins, guidelines have been created to help develop and maintain hydrophytic or "water loving" plants in such basins. Treatment basin construction and design should create a basin with gentle slopes, "wavy" sides and areas of both shallow (<30 cm) and deeper (>30 cm) water with features such as hummocks or shelves to increase vegetation types and diversity as well as increase the basin's wildlife habitat value. Topsoil should be replaced and spread over the new basin surface to increase available seeds or plant material. Any erosion control plant mixtures applied should contain a portion of plants that will tolerate moist conditions, which will help revegetate the basin. The treatment basin location should be examined for potential revegetation materials prior to construction by using seed bank studies and/or walking surveys of local species. The examination of local available vegetation and seed sources will give the site designer/manager a better understanding of what types of non-planted vegetation may develop in the basin and further help them to decide if active revegetation options such as planting should be planned. If the locally available seed and plant sources are in sufficient numbers, passive revegetation or a combination of passive and active revegetation should be used in the treatment basin. If inadequate seed and local sources exist, active methods such as planting, seeding, and salvage sources could be used. Each revegetation method is discussed in reference to cost and management effort. Management guidelines and suggestions for maintaining hydrophytic vegetation are discussed for both passive and active revegetation. Management should not involve the mowing or application of herbicides to the treatment basin, unless special circumstances arise. There are suggestions to manage nuisance species such as purple loosestrife, cattails and thistles, as well as dealing with excessive algal mats which may interfere with seed germination. Examples of hydrophytic species and their moisture tolerances are given as well as suggested species to be actively planted or seeded into the treatment basin. Additionally, experience from constructed treatment basins in the Wetland Reservoir Subirrigation System project is presented. This bulletin provides a good resource for those who plan to construct or manage a treatment basin. These guidelines provide information on establishing and managing vegetation within the treatment basins, which can improve the basins' ability to improve water quality. This bulletin also provides practical advice based on experience at other constructed treatment basins.