MONTEVIDEO -- Breaking with years of precedent, the Joint County Ditch 7 Authority for Hawk Creek decided to replace two aging, timber bridges in Lone Tree Township of Chippewa County with box culverts.
The action came on a 3-2 vote at the authority's meeting Wednesday in Montevideo.
Chairman Gale Dahlager, Renville County's lone representative on the board and its chairman, cast the deciding vote. Chippewa County Commissioners Jim Dahlvang and Gene Van Binsbergen author-ed the motion to replace the bridges with less costly box culverts, as recommended by engineers for the authority. Kandiyohi County Commissioners Dean Shuck and Richard Larson voted against the motion.
They had earlier indicated their support for a request by township officials to install culverts larger than those recommended.
Replacing the two bridges with culverts will save an estimated $262,000, according to information provided at the meeting.
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Under an agreement dating to the dredging of Hawk Creek in 1962, property owners in the watershed -- including the cities of Willmar, Raymond, Clara City and Maynard -- are assessed for the costs of replacing bridges in townships along the waterway.
Lone Tree Township officials have always asked that bridges be replaced with bridges to avoid the risk of ice jams and flooding. This time around, township attorney John Kolb said he understood that the authority could not afford the greater cost that bridges represent.
But Kolb said that the township wanted to see culverts larger than those recommended by the engineers. The larger culverts would more closely approximate the channel opening that now exists under the bridges, he explained.
Chuck De Grote, a Lone Tree Township landowner, said he and others who farm near the bridges are concerned about the potential for crop losses. Crops losses over the life of the culverts could be much greater than the savings the concrete structures offer, he told the authority.
But two engineers for the authority provided information that suggested that bridges or oversized culverts would do nothing to alleviate flooding, while costing much more.
Chippewa County Engineer Steve Kubista said that the recommended culverts are designed to meet the hydraulic needs of each location based on state requirements.
Ditch Authority Engineer Peter Jay Sarberg said that the Hawk Creek channel is designed to handle water flows of roughly a 25-year flood event. At some point greater than a 50-year flood event, the waters will flood beyond the banks of the channel, no matter the size of the bridges or culverts.
In a 100-year flood event, the recommended culverts would allow floodwaters to stage six inches higher behind them than the bridges they will replace, Sarberg said.
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Installing bridges or culverts with a greater flow capacity than the channel itself is a "misuse of public dollars,'' said Owen Gustafson, a Stoneham Township farmer who has been urging the Ditch Authority to follow the recommendation of its engineers.
The Ditch Authority decided to:
- Replace bridge L7736 on Lateral E to Hawk Creek between sections 4 and 5 with two, 12-by-10-foot box culverts at an estimated cost of $157,000.
The estimated cost for a bridge is $314,000, and the estimated cost to install two oversized 12-by-12-foot culverts is $177,000 to $182,000.
- Replace bridge L7667 on the main channel between sections 6 and 7 with three 12-by-12-foot box culverts at an estimated cost of $272,000.
The estimated cost for a bridge is $377,000, and the estimated cost for oversized 12-by-14-foot culverts is $320,000.
