In a productive field, “I’d go with a sediment dam versus a grassed waterway,” says Alberta, Minn., farmer Jim Krosch. In 2004, he installed four, 4-ft.-tall sediment-control dams to intercept runoff in a field that falls 8 ft. in half a mile.

“Water would cut gullies in the field every year. We’d work them shut with a digger; then they’d wash out again. We were losing a lot of soil. Now there’s very little erosion off the field.”

Krosch crops all his sediment-control dams, including a large, L-shaped dam in another field that’s about 6 ft. high. “I’ve never had a problem farming around them,” he says. “When the rest of the field has been ready to work, the basins have been, too.”

One year, he did have some crop loss when an intake pipe got plugged up with residue and failed to drain properly. Another time, water overtopped one of the berms, damaging it.

WASCOBs don’t stop sheet and rill erosion, so at least 30% residue cover is needed to reduce sediment loading in the basin, Hellermann says. Krosch, who farms very heavy clay loam soils, also suggests installing some subsurface tile at the top of the drainage-way to cut surface flow volume and extend the life of the WASCOB. Eventually, the ponding area fills up with sediment and has to be scraped out.