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Pond Site
Prior to hiring a contractor and starting construction on a pond, landowners are advised to have a good understanding of the factors that will make to difference between a nice pond and a big dry hole. Upon a landowners request, GCSWCD technical staff can arrange a visit to your property to determine if your site is suitable for a pond. The GCSWCD will evaluate the proposed pond location, water sources, soils and out flow drainage features.
Before making a commitment to construct a pond, landowners should be aware of the factors which will directly impact the ponds functioning as well as understand any potential regulatory (permitting) requirements. While the GCSWCD does not warrantee the success or failure of a pond site, we can provide valuable information to help you make your decision.
Water Supply First and most important is determining if your site has an adequate water supply to maintain the pond under a range of weather conditions. While a site may appear wet and seem perfect for a pond, summer can be long and hot with evaporative losses greatly reducing the water level. Water sources for ponds can be either surface water runoff or groundwater from springs. Surface Water: Generally, the GCSWCD recommends that the pond site have a surface drainage area ratio of 15 acres of watershed for each surface acre of pond. This standard was developed by the USDA Soil Conservation Service for agricultural ponds, and it provides for suitable runoff to maintain the pond level during all but the most severe of droughts. The watershed for your pond will be all of the surface area that drains to the pond. Groundwater: In most cases, it is not recommended that a pond be developed using springs as the primary source of water. Often, springs can go dry in the summer droughty months, with the pond receiving inadequate water to maintain an acceptable water level. Even springs with an established history of flowing year round may not provide an adequate water supply to overcome evaporative losses from the pond during the summer months. Soils Evaluations
One of the most important factors influencing a ponds success, is the ability of the native soils to hold water. While it is possible to use liners on smaller, garden style ponds, these liners are expensive and often difficult to install properly. A pond site must contain a soil with suitable fines (silts and clays) to provide for a sealed condition. Sites with shallow bedrock, coarse soils or even clay soils with stratified layers of sands or gravels can all present a problem for pond development.
To determine if your soil is suitable for a pond, the GCSWCD will first consult the Greene County Soil Survey to obtain general information on the soil mapped for the location. During the initial site visit, the District will examine exposed soils as well as look for signs of bedrock or well drained conditions. If the site appears to have suitable soils, the District strongly recommends a follow up visit to conduct soils test pits in the location of the pond. Test pits require advance scheduling, and the landowners is responsible to have a backhoe or small excavator with an operator at the time of the visit. Test pits will be scheduled only after an initial visit is made to evaluate the site. Pond Overflow
While a suitable water source and soils are the primary factors influencing the ability to construct a pond, it is equally important to consider the drainage from the pond when it overflows. The ponds outfall must be adequate to provide for overflow during heavy runoff events with causing damage below the pond. There have been many examples of soured relations with the neighbors over a new ponds drainage so we advise you to keep your down slope neighbors.
In this area of the country, the laws regarding natural watercourses and their flow is rooted in centuries old English law which has changed very little over the years. In general, while a landowner has rights to the use of the natural water flow as it passes through their property, any diversion of the flow from its natural course can create a substantial liability for the pond owner. Keep in mind that pre-existing conditions may be vastly different from post-construction if the pond intercepts, and then concentrates the overflow during storm events. Make sure you have an adequate overflow and be considerate of your neighbors. |