Engineers tell Vernon County many PL-566 structures are hydraulically undersized and would require near-rebuilds to meet new rainfall data

Mark Erickson and NRCS State Conservation Engineer Steve Becker told the board that the dams27 original designs rely on older rainfall datasets and are hydraulically insufficient under modern standards. "The dams were designed with rainfall data from the 195027 and 196027s. The dams are not designed for the current rainfall amounts," Erickson said, adding that in many cases repairs would amount to building new structures because outlet pipes are too small and sandstone abutments allow seepage beneath embankments.