Laserfiche WebLink
<br />the drainage basin and adjacent basins shall be inventoried <br />and documented. <br /> <br />a. When at least 50 years of streamflow records are <br />available, a statistical. analysis of the individual <br />streamflow record and/or a regional egression analysis <br />of the data shall be made to determine the flood peaks <br />of selected recurrence intervals. <br /> <br />b. When from 25 to 50 years of streamflow records are <br />available, the hydrologic analysis shall include a <br />statistical analysis in accordance with rule 5.B.2.a <br />and a comparison with similar watersheds. <br /> <br />c. When from 10 to 24 years of streamflow records are <br />available, the hydrologic analysis shall include a <br />statistical analysis in accordance with 5.B.2.a, <br />comparisons with similar watersheds, and flood <br />estimates using hydrologic models and precipitation <br />records. . <br /> <br />All drainage basin characteristics lhat affect the <br />rainfall-runoff relationship shall be documented, <br />including, but not limited to, delineation of basin and <br />subbasin boundaries, size, shape, length, slope, <br />general aspect, elevation extremes, time of <br />concentration, land use, and soil types and <br />compos it ions. <br /> <br />When actual precipitation records of major recorded <br />storm events are available from area weather stations, <br />such data shall be used in conjunction with rainfall <br />data. <br /> <br />d. <br /> <br />When less <br />available, <br />calculated <br />estimates <br />records. <br /> <br />than 10 years of streamflow records are <br />the selected flood frequency flows shall be <br />by comparison to similar watersheds and by <br />using hydrologic models and precipitation <br /> <br />3. DrainaQe Basin Conditions. The hydrologic analysis shall <br />be ba&ed 01'1 drainage basin conditions that will exist in <br />the cOD':ounity at least 12 months following completibn of <br />the report, except if future urbanization of a basin is <br />"kely to occur, the hydrologic analysis shall be based on <br />'reseeable development in the basin. <br /> <br />-10- <br />