A pond can be a valuable asset to a farm or suburban landowner according to Bob Schultheis, natural resource engineering specialist with University of Missouri Extension.

A well-planned and built pond can provide livestock water, fishing opportunities, soil erosion control, fire protection, and a place to relax. But a good, usable pond is not inexpensive to build.

“Undersized ponds and leaky ponds are two common problems I encounter,” said Schultheis. “A properly-sized pond will have one acre of surface area for each 10 to 15 acres of watershed that drains into it. Cutting corners on size to save money only ends up costing more later in repairing erosion damage and downstream neighbor relations.”

Leaky ponds are frequently due to the wrong soil being used for sealing or because the right soil was improperly compacted. Landowners building or enlarging a pond in the Ozarks are warned to do it when the soil is moist and sticky, never when the soil is dry, if they want it to hold water.

Many of the red and yellow clay soils in the Ozarks are leaky in their natural state. Pulverizing these soils with a disk breaks down their blocky soil structure, and keeping them moist during the recompaction process and after construction will help the pond better hold water.

Compaction of several four to six-inch thick layers of moist clay in the pond bottom will usually be needed to assure a seal. Additives such as bentonite clay or soda ash may need to be mixed with some soils to keep them from leaking.

Schultheis cautioned against relying on bulldozers for soil compaction. Bulldozers have a large “footprint” that spreads out their weight, resulting in ground pressure no greater than a person just standing on the ground.

A better choice is a wheel tractor and disk, or a sheepsfoot roller (like the spiked drums the highway department uses when building roadbeds), to compact each clay layer before adding the next one.

“A well-built pond should fill within one year, and seepage plus evaporation should be 12 inches or less in hot summer months and four inches or less in winter months,” said Schultheis.

A county soil survey book, available through any federal Natural Resources Conservation Service or on-line at soils.missouri.edu, can help identify good pond building sites and soil properties at depth. Also ask for Agricultural Handbook Number 590 Ponds, “Planning, Design, Construction,” or get it on-line at www.info.usda.gov/CED/ftp/CED/ah590-ponds.pdf.

The Missouri Pond Handbook, available from the Missouri Department of Conservation, or on-line at www.conservation.mo.gov, can help in developing and managing both ponds for fishing.

Details on reducing pond seepage and maintaining pond dams are available at University of Missouri Centers (guide sheets G1555 and G1548) or online at extension.missouri.edu.

Schultheis can be contacted at the Webster County Extension Center, 417-859-2044.