Laserfiche WebLink
<br /> <br />as it may be, there will be times when the monitoring team is <br />forced to stand back and let nature take its course. <br /> <br />Notes <br /> <br />Monitoring flood works at night is particularly dangerous. All <br />team members should have waterproof flashlights that are in good <br />working condition. Chemical light sticks may be given to team <br />members as an added safety device. Life jackets are a particularly <br />good addition to the equipment list of the monitoring team. Team <br />members should always stay within sight of each other. <br /> <br />There are many things to look for while monitoring flood <br />control devices. Some problems require immediate attention. <br />Others are just watched for additional danger signs. Monitoring <br />teams should be required to report anything out the usual and seek <br />expert opinions when in doubt. <br /> <br />Sand boils are a common problem along levee systems. Team <br />members should be alert for sand boils and report their discovery <br />to higher authorities. Boils will have to be monitored for the <br />duration of the high water. While most sand boils are harmless, <br />some can quickly undermine levees and result in the failure of the <br />flood control structure. <br /> <br />Sand boils are caused when water finds a path under a levee or <br />flood control device and resurfaces behind the device like an <br />artesian well. They can range in size from a few inches in diameter <br />to several feet in width. A single sand boil may occur or they may <br />be grouped into what is commonly called a "boil field." <br /> <br />It is important to be able to recognize the different types of <br />sand boils. Sand boils may be classified as either "dirty" or <br />.- '--~"c1ean:" illS alSolmporfiint to recoglllze mat the character 01 the <br />sand boil may change with differing water levels or as time <br />progresses. <br /> <br />A clean sand boil does not transport sand or soil in the water <br />flow. Although a nuisance, this type of boil is not dangerous and <br />need only be monitored for changes. <br /> <br />Dirty sand boils are a different matter. Boils that are <br />discharging sand and soil, especially if they are within 100 feet of <br />the toe of the levee, are serious. A dirty sand boil may flush <br />en<;mgh material out from under the levee or structure to cause it's <br />failure. Dirty simd boils should be reported immediately. <br /> <br />Animal burrows can provide an easy conduit for water through <br />flood control structures. The flow of water through a burrow can <br /> <br />Page7-4 <br />