Laserfiche WebLink
<br />. , Base mapping and field surveys are performed. <br /> , The proper hydrologic method ( flow determination) <br /> for a particular drainage basin is selected . <br /> , The water surface elevations (.flood levels) wh ich <br /> <br />. <br /> <br />are representative of a projected event are <br />computed. <br />Datum consistency between the floodplain delinea- <br />tions (flood outline maps) and on-the-ground con- <br />ditions is maintained. <br /> <br />a) Base Mapping and Field Surveys <br /> <br />, <br /> <br />Base Mapping <br /> <br />. <br /> <br />The 100-year floodplain information and data <br />ultimately must be delineated on a map of suita- <br />ble scale and detail. The map may be an existing <br />map (USGS quadrangle map, town, county, etc.) or <br />a large scale topographic map. <br /> <br />-15- <br /> <br /> <br />. <br /> <br />Floodplain outlines shown on large scale topo- <br />graphic (1" = 100' or 1" = 200' with 2 foot con- <br />tours) maps with cultural features are desirable <br />for administration of flood hazard zoning regula- <br />tions. In this way the floodplain outlines can <br />be defined with more accuracy, and physical fea- <br />tures can be shown more clearly. Accuracy is <br />