Date of this Version
GREAT PLAINS BEEF CATTLE HANDBOOK, 1992
During recent years, most open feedlot operators have found it desirable and, in some cases, necessary to install runoff control facilities. Even though the primary purpose of feedlot runoff control systems is the prevention of water pollution, many producers have found that good management of these systems also offers limited economic benefits in the form of fertilizer nutrients and supplemental irrigation water. Well managed runoff control systems also reduce weeds, odors, insects and muddy areas at or near feedlot edges. The runoff control system that has proved most satisfactory for all areas of the country is one consisting of clean water diversion, runoff collection, a solids settling facility (or debris basin), a runoff holding pond and pond dewatering equipment (Figure l). Management consists of cleaning solids from the settling facility and pumping out the holding pond when necessary. The amount of labor required for proper management of runoff control systems is not excessive, but this type task usually has a low priority in a general farming situation and, therefore, is often not accomplished when it should be.
A lack of cattle lot maintenance can lead to undrained muddy areas and to nuisance conditions such as fly and odor problems. Such conditions have also been shown to decrease animal performance. If the settling basin is not cleaned when solids build-up reaches the design-full level, the outlet clogs and more solids carry through to the holding pond. Allowing solids to reach the holding pond reduces its capacity and shortens its useful life unless periodic sludge removal is practiced. Additionally, an excessive accumulation of solids and undrained liquids in the basin frequently results in odor and insect problems. Failure to pump out the holding pond on a timely basis may lead to overflows with dubsequent loss of crop nutrients, water pollution, and potentially to a lawsuit.
Clean Water Diversion
To minimize the amount of water which must be handled through a runoff-control system; diversion terraces, channels and roof gutters should be utilized and kept in good repair. Keeping clean water diverted away from feedlots decreases the quantity ofliquids to be separated in the settling basin and subsequently stored in the holding pond. Control of clean water effectively reduces the required size of the holding pond or can increase the time between dewatering operations.
In· situations where clean water is to be collected for use as irrigation water, it should be diverted around the settling basin directly to the holding pond. Careful sizing and design of the holding pond is essential to ensure adequate capacity for storing both the diverted clean water and feedlot runoff.
Runoff can be collected from feedlot areas and diverted to settling basins and holding ponds by using curbs, channels, terraces, pipes or combinations of these. All parts of the runoff control facilities need to be kept free of obstructions such as weeds, tree limbs, and accumulations of solids. Obstructions in runoff collection devices may cause overflows with resultant pollution or nuisance conditions due to unconfined feedlot runoff. Obstructions can also cause solids to settle in areas where removal may be difficult, or impossible. Routine moving and clean-up supplemented with periodic grading and shaping of earthen runoff collection devices will effectively minimize the development of erosive or low, soggy areas.