As many of you know the South Fork changes its course below the Heise bridge every year.  Because the river is beyond the restriction of the canyon walls and in the alluvial plain, the river goes where it wants.

When the south channel basically closed off a few years ago, this placed pressure on the north channel and its bridge.  This last summer the evidence of the increased flows became evident as the bridge abutment on the north side of the north bridge began to erode.

Madison County has OK’d a $134,000 project to shore up the north bridge at Twin Bridges.

According to Randy Johnson, a project manager at Forsgren, the project will consist of the placement of precast concrete units that will be tied together with cable to protect the abutments. The project will also use regular rip-rap and some poured concrete to rebuild footings. He said by using precast concrete sections instead of regular riprap, the bridge’s piers can be protected better with less erosion and with less flow restriction.“We’re trying to minimize the energy that’s created by the restriction of the bridge,” Johnson said.

Madison County officials plan to continue to work with other government agencies to deal with the flow disparity between the two channels.

Some of this article was taken from a Standard Journal article.

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