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<br /> <br />There are two basic locations where expedient flood protection <br />will be built. In areas protected by levees, the structure may be <br />raised by adding material to increase the levee height. Where <br />levee systems are not present, expedient flood works can be <br />constructed in open areas a,long waterways or roads. Methods for <br />dealing with each situation will be covered in this chapter. <br /> <br />Notes <br /> <br />The process of increasing the height of a levee by placing <br />material on the crown is called capping or topping. A crown is the <br />flat top surface of the levee. <br /> <br />I Crown <br />.... <br />I <br /> <br /> <br /> <br />In a high water event, immediate consideration must be given <br />to the levee gradeline. Although standard practice requires that <br />gradelines be kept current, new survey levels should be run over. <br />any area that appears to be below the predicted flood crest or <br />appears to have sunken. If there is a need for capping, new <br />gradelines must be established for each section of levee. Normally <br />capping is constructed to a height of two feet, plus or minus 1/2 <br />foot, above the predicted flood crest. <br /> <br />It is important to prepare the levee for capping. The bond <br />between the levee and the capping must be as watertight as <br />possIble. All depreSSIOns, SUCh as paths or ramps, should oe-- <br />restored to the natural levee grade and provided with an adequate <br />cross section. Sandbags may be used to bring any low ramps up to <br />grade. If time permits, the levee crown should be scarified to a <br />minimum of two inches by plowing, or similar means, to improve <br />the bond between the levee crown and the capping material. <br /> <br />There are four different methods that can be used to cap a levee <br />and prevent overtopping. These are: earthfill, sandbag, flashboard, <br />and mudboxes. The type of capping is determined by local <br />conditions and will vary from location to location. No single <br />method is best for all sites. The Corps of Engineers can help local <br />authorities determine the best method to use in their specific <br />situation. <br /> <br />The flood fight plan should describe various flood capping <br /> <br />Page4-3 <br />