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<br />. <br /> <br />. <br /> <br />There are several abandoned drainage canals that discect the <br />basin which could possibly alter the true drainage pattern of the <br />basin. In addition a sizable piece of the lake drainage area <br />(2.0 square miles) may be drained by Salt Creek. A field <br />inspection of the affected areas could not confirm the true Lake <br />Minnequa drainage area. It should therefore, be noted that the <br />drainage area used in the MSM hydrologic analysis must be <br />considered a maximum possible drainage area and the lOa-year <br />flood in and out of the lake must be considered a maximum <br />laO-year flood event. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />With this in mind a detailed and expensive determination of the <br />floodplain limits downstream of the lake is not recommended and <br />therefore was not conducted. The laO-year floodplain downstream <br />of the lake was therefore determined using the following <br />procedure. The depth of the lOa-year flood through the outlet <br />section of Lake Minnequa was determined to be 1.5' from the lake <br />stage-discharge curve. As the flow continued into the street <br />system the depth of flooding decreased as the floodplain spread <br />out and at some point the average depth of flooding became 1.0 or <br />less thus being classified as a Zone B shallow 100-year <br />floodplain. The lOa-year floodplain downstream of the lake was <br />therefore defined by rough typical street capacity calculations <br />using available city topographic mapping and a field inspection <br />of the area. Since the flooded area has a free outfall across <br /> <br />. <br /> <br />e' <br /> <br />. <br /> <br />. <br /> <br />-6- <br /> <br />. <br />