Take Advantage of Dry Conditions To Remove Sediments from Dams, Dugouts

 BROOKINGS, S.D. -- South Dakota producers who rely on dams and dugouts for watering livestock should consider removing sediment or rebuilding dams and dugouts this summer or fall, a South Dakota State University Extension specialist said.

SDSU Extension Water and Natural Resources Specialist Charles H. Ullery said conditions are good for using heavy construction equipment because water levels are very low in the western two-thirds of the state. Some dams and dugouts are empty.

"While this won’t solve the current water shortage or poor water quality problem, it does offer an opportunity to increase the storage capacity of dams and dugouts for future years," Ullery said.

The storage capacity of all dams and dugouts decreases with time as sediment from soil erosion accumulates.  How much and how quickly sediment accumulates depends on the amount of erosion in the watershed, which is affected by management practices on rangeland and cropland.

Natural Resources Conservation Service design criteria for dams and dugouts used as a source of livestock drinking water call for a capacity to the store annual watershed runoff expected on the average once every two years. The minimum design depth is 10 feet in eastern South Dakota, and 12 feet west of the Missouri River.

Accumulation of sediment reduces both the depth and amount of water stored when the dam or dugout is full, Ullery said.  During extended drought periods, that reduced storage capacity means dugouts dry up sooner. Total salts and sulfates also reach problem levels sooner as evaporation concentrates salts.

Sediment is typically removed using draglines, bulldozers or earthen scrapers.

When sediment is being removed, storage volumes can be increased if the watershead area is sufficient to meet design criteria. Take advantage of the dry conditions to make repairs to damaged pipe, grass or concrete spillways. Eroded areas on the fill or in waterways above and blow the fill in dams should be corrected, too.

Technical and cost-share information about removing sediment removal and general construction of dams and dugouts is available from your local conservation or NRCS office.
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Contact: Charles Ullery, (605) 688-5144
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Lance Nixon, Editor
AgBio Communications Unit
South Dakota State University
ACC, Box 2231, Rm 200
Brookings, SD 57007
Telephone: (605) 688-4653
Lance_Nixon@sdstate.edu