Road closure on Iowa 150 south of Independence
AMES, Iowa – July 10, 2009 – Iowa 150 is closed to traffic in both directions at mile marker 36.8, approximately three miles south of Independence, in Buchanan County, according to the Iowa Department of Transportation’s (DOT) Office of Bridges and Structures.
Southbound Iowa 150 is detoured at U.S. 20, east to Buchanan County Road W-40, south to Buchanan County Road D-47, then west back to Iowa 150. Northbound Iowa150 traffic will follow the reverse route.
The road is closed due to flooding around a scour-critical temporary bridge over Bear Creek, which must be inspected once the flood waters recede before the roadway can be reopened.
Bridge scour is a situation that can frequently occur during flooding. Scour is the result of the erosive action of flowing water, excavating and carrying away material from the bed and banks of streams, and from around the piers and abutments of bridges.
The Iowa DOT has contingency plans in place that protect these scour-critical bridges and motorists who use them. Where feasible, the Iowa DOT has installed scour-prevention measures, such as riprap or articulated concrete block mats. These countermeasures reduce the need for close monitoring of the structures during flooding.
Where such physical measures are not practical or feasible, the Iowa DOT's plan calls for the closure of any scour-critical bridge when the water surface elevation reaches the predetermined critical flood level.
In the past, it was difficult for the Iowa DOT to accurately predict when this critical flood level might be reached or to determine when a structure was at risk, without a visual inspection.
Today, with the aid of advanced bridge monitoring technology, the Iowa DOT is able to predict flooding conditions more accurately and respond proactively to bridges most at risk.
Through the Iowa DOT's use of the BridgeWatch™ technology, traveler safety is significantly increased and public resources used much more efficiently. Iowa DOT personnel are now able to examine those bridges at risk, rather than blanketing an area of the state where flooding may be occurring. When bridges are at risk, Iowa DOT personnel are automatically notified by the BridgeWatch technology so they can closely monitor the structure.
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Contact: Norm McDonald at 515-239-1206 or norman.mcdonald@dot.iowa.gov
