Access digital copies of guides and regulations publications from the Nebraska Game and Parks Commission.
Issue link: http://digital.outdoornebraska.gov/i/605475
excessive growth of aquatic vegetation, helps withstand water losses due to evaporation and leakage, and reduces the negative effects of sedimentation. Some shallow water is necessary for fish spawning and nursery areas and to produce food, especially aquatic insects, for fish. As a general rule, 25% of the pond should be at least 10 feet deep in southeastern Nebraska and at least 12 feet deep in western and northern Nebraska. No more than 25% of the pond should contain water less than 4 feet deep. Ponds should also have about 50% of the impounded area at least 8 feet deep to prevent excessive growth of aquatic vegetation, especially those with good water clarity. The slope from the shoreline to a water depth of 4 or 5 feet should be no flatter than 1 foot vertical drop for every 3 horizontal feet. Then create several benched flat areas to facilitate placement of structure (rock piles, weighted trees, pallets etc.) for fish habitat (see page 41regarding artificial habitat). The slope should then taper to at least 8 feet in depth for two- thirds of the distance from the dam to the upper reaches of the pond. Although the shoreline may have to be graded to attain a 3:1 slope, grading may be cheaper than the future costs of aquatic vegetation control. Slopes greater than 2:1 should be avoided because of safety hazards and the likelihood of shoreline slumping into the pond. Having deeper water doesn't necessarily mean more fish can be produced in a pond because fish production is based primarily on microscopic plant and animal growth occurring in the upper 3 to 5 feet of water. Also, water greater than 15 feet deep may not be used by fish during summer months due to low oxygen levels usually present at those depths. Site Preparation Once a site has been selected, all trees, vegetation, roots, stumps, and large rocks must be removed from the dam site. If they aren't, the decay of organic materials will create passages that will allow water to seep through the base of the dam. Large rocks may prevent the soil from being properly compacted, which also could result in seepage. All topsoil containing organic material removed from the pond site should be stockpiled close by. Once construction is completed, the topsoil should then be spread over the dam and spillway to promote grass growth, and over the excavated basin to promote fertility and sealing. Trees and brush should also be removed from areas that are planned for swimming and wading. Small ponds will likely need to have all brush and trees removed since the majority of the fill material for construction of the dam will likely have to come from the basin. Some of the trees and brush that are removed can be stockpiled and then placed back in the pond basin or the upper reaches when construction is done. They will provide fish habitat, enhance production of fish food items, such as zooplankton and aquatic insects, and help trap sediment and debris. Trees and brush in non-excavated areas of the pond bottom should be left intact, especially in larger ponds. They will also provide fish habitat and become a substrate on which aquatic organisms can grow. To minimize impacts to wildlife, existing cover in draws and waterways leading into the pond site should also be left undisturbed. This will also help to enhance water clarity and lessen shoreline erosion and sediment problems as the pond fills. Decomposition of flooded vegetation will also improve water clarity by facilitating settling of suspended soil particles. Catfish-only ponds should have all debris removed and the bottom left smooth to reduce spawning sites and lessen the likelihood of the pond becoming overpopulated with small catfish. See page 39 for additional information on establishing and improving fish habitat. . . . . . . . . . . . . . . . . . . . . second edition • Nebraska Pond Management • 13