Bridge to the Future

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Published on: Nov. 2, 2007

To show their appreciation for the privilege of mining gravel from a large bar on Ambrose’s land, county road crews helped build the erosion-control structures.

Ambrose’s efforts succeeded. Not only did erosion stop, but the structures actually encouraged Little Tavern Creek to deposit sediment where it previously had been carving it away.

Then Little Tavern threw a tantrum. A 15-inch rainfall during the last weekend of July 1998 sent a torrent of water ripping through the valley, destroying crops, property and stream crossings. As a result, Miller County received a grant from the Federal Emergency Management Agency. The county commission decided to use the money to upgrade Massman slab, a low-water crossing just downstream from Ambrose’s and Kemna’s land.

The crossing was important because it provided access to the area for feed, fertilizer and livestock trucks, school buses and commuters. County officials had been dealing with floods and washouts on the bridge since the first concrete slab was installed there in 1926. Each time there was a problem, the county poured more concrete around the trouble spot to keep the bridge serviceable for a few more years. This time, however, the county decided to fix the problem once and for all.

The old bridge consisted of a concrete deck approximately 18 inches tall with an opening underneath to let water pass. The county removed this structure. In its place, it laid four round metal culverts, each 48 inches in diameter, parallel to the stream flow. After pouring concrete walls around the upstream and downstream ends of the culverts, they filled the middle with gravel and poured concrete over the whole thing, creating a flat roadbed. The new bridge was approximately 6 feet tall, with the four culverts 2 or 3 feet above the creek bed on the downstream side.

The structure was impressive. It also was doomed to fail. Without the benefit of advice from professional engineers, county officials did not anticipate that the creek would wash out the bottom and edges of the bridge. Before long, they had the same problems that plagued the old slab bridge, but on a larger scale.

Far from being a solution, the new bridge actually created new problems. The four culverts were too small to handle flood flows, so the bridge became, in effect, a dam. Even medium-sized rains caused water to back up half a mile above the bridge.

“You’d get up in the morning and hear it raining,

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