AMES, Iowa--Farm pond owners need to consider some possible damaging effects brought by Iowa’s spring floodwaters, an Iowa State University (ISU) Extension aquaculture specialist advises.

“Check farm ponds for damaging effects on water quality, fish populations and dam integrity,” says Rich Clayton, author of Managing Iowa Fisheries: Farm Ponds (PM 1352B).

Water quality can be affected by both sediments and dissolved nutrients in the floodwaters, according to Clayton. The sediment load coming into a pond during a flood event will increase the siltation loading into the farm pond, resulting in decreased pond depths.

Nutrients in floodwater also can have a detrimental effect on the fish population and associated ecosystem within a pond by causing increased plankton and plant growth, he says. Stocked fish can be flushed out of the pond and into adjacent streams, and non-desirable species can be carried into the pond, creating competition with the desirable species for food and space. 

Increased water flow into a farm pond can damage the levee, dam or emergency spillway. Clayton advises inspecting the levee or dam for erosion as well as inspecting water control structures and spillways for debris that may impede water flow. Logs and limbs can block spillway or standpipes that help control the water level during normal conditions.

Use caution when removing such debris from these structures, he says. For more information, obtain PM 1352B online, http://www.nrem.iastate.edu/extension/fisheries/publications/PM1352B.pdf, visit the Fisheries Extension Web site, or contact Clayton at rclayton@iastate.edu.

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