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Hydraulics Engineering


Debris Control Structures Evaluation and Countermeasures
Hydraulic Engineering Circular No. 9

Appendix B - State Survey

State Information
Texas Provided a web site for their hydraulic manual. This manual generally flags the issue and provides some general guidelines (use a single box in lieu of a double box, multiple boxes at different elevation, increase freeboard, and increase span lengths). It is indicated in the response that problems associated with debris doesn't appear to be a major problem for the state.
Oklahoma Devices to control debris: debris sweeper, increase freeboard, and single or triple cell RCB in lieu of double RCB. No information available for debris sweeper since it is a new installation.
Michigan No design procedures, practice, devices or strategies have been employed to control debris accumulation problem; other than, immediately remove any debris accumulated at the structures.
Missouri No standard plans for debris control structures, and they are not routine used in their drainage designs.
Connecticut Discourage the use of debris control structures on culverts. Use rounded nose for multiple culvert or for bridge piers. Debris racks have been used with varying degrees of success. However, these structures are discouraged except where absolutely necessary because they are invariably maintenance intensive.
Virginia Very limited experience with debris control structures. A few structures were constructed about 25 to 30 years ago. Some or possibly all of these structures have been damaged in storms and have been removed.
Montana Large culverts - They have tried H-piles placed upstream of the culvert on a limited basis. Bridges - location of piers, minimize number of piers, maintain adequate freeboard, and removal of any debris accumulations (maintenance).
South Dakota Multiple barrel box culverts - extend the upstream end of the interior walls to the end of the apron with a height at the upstream end set at or above a computed water surface elevation (sloping nose). Bridges - use pier walls instead of series of columns. Safety bars at the upstream end of the culverts have services as debris racks and have reduced the culvert performance.
Mississippi They have used drift deflectors and web walls for bridges.
Kansas Bridges - no piers in the main channel, webwall for the width of the pier, align the piers to the streamflow, structure sized assuming a debris raft is present (drift potential is determined based on historical records, photos, and a site visit). Structures that span the main channel show limited amount of drift buildup.
Florida District 3 will be installing a debris sweeper on one of their bridges, and they will be using this device on several other bridges depending on how it functions on the first bridge. Some of the local bridge owners have installed sacrificial 18" piling immediately upstream of the bridge pier to essentially shift the debris buildup and cleanup away from the structure.
Indiana Recommend 80' to 90' minimum span lengths for large stream crossings, and they have used debris deflectors. They are currently performing a research project to assess the success rate of the pile debris deflectors.
South Carolina They have designed various structures on a case by case basis using the old version of HEC-9 as a guideline. They have no standard plans for these structures. There have been no significant complaints made by their field office.
Arkansas They have not used any debris control structure at any culverts or bridges.
Tennessee Have used debris fins at the inlet of culverts. They have also installed debris sweeper at two bridge sites.
Kentucky They have not used any debris control structure at any culverts or bridges.

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Updated: 04/07/2011

United States Department of Transportation - Federal Highway Administration