Excessive rains that brought historic floods to many parts of Louisiana last month will cost farmers at least $10 million in lost revenues and damage to their crops and livestock.

The impact includes the costs of replanting flooded fields, potential crop yield losses and having to relocate livestock herds, said LSU AgCenter economist Kurt Guidry, who has been surveying the damage around Louisiana.

At least six inches of rain fell between March 7 and 11 in much of Louisiana, with some areas receiving more than 20 inches of rain. Though floodwaters have mostly receded from the heaviest-hit parishes in northern Louisiana, that water is now creating issues farther south in places that didn’t flood when the rain first hit, including Franklin and Catahoula parishes, Guidry said.

President Barack Obama has declared 36 parishes, most in northern and central Louisiana, as disaster areas eligible for federal assistance.

Guidry’s preliminary estimate of flooding damage to the agriculture industry is $10 million to $15 million, but that number is likely to grow.

“This estimate is still evolving as more information is collected and decisions are made on the amount of acreage that will need to be replanted,” he said.

Cornfields in north Louisiana saw some of the greatest damage. As many as 55,000 acres of corn were flooded and will have to be replanted.

“Fortunately, for most of the major row crops in Louisiana, planting hadn’t begun to any significant measure,” Guidry said. “The impact for these crops to this point has been disruption of field preparations, which could result in planting delays that could ultimately impact yields.”

The U.S. Department of Agriculture has reported that several Louisiana commodities are behind the five-year average pace for planting and harvesting. Only about half of Louisiana’s corn acres were planted as of April 3, while 82 percent of acres had been planted by that time on average in the past five years.

Rice and grain sorghum planting, as well as wheat harvest, are behind the five-year average too. Planting delays may force some farmers to switch acreage — especially corn acres — to other commodities, Guidry said.

At least 400 head of beef cattle died in the flooding, and livestock operations are facing increased costs associated with relocating their herds and losing available land for grazing, Guidry said. At least 1,500 bales of stored hay and 2,000 acres of fencing were also lost in floodwaters.

AgCenter personnel have been assisting in damage assessments and other recovery efforts, he said.