Laserfiche WebLink
<br />'~ 1>4,' d <br />tJ .-' <br /> <br />Model floodplain regulatlons prepared by the Colorado Water Conservation <br /> <br />Board (CWCB) offer two options for management of the 100-year floodplain. <br /> <br />These are the Hazard Area Concept and the Ploodway Concept. <br /> <br />The Hazard Area Concept defines an a.rea of the floodplain based on a <br /> <br />depth criteria. The model prepared by the CWCIl in 1974 recommends that areccs <br /> <br />where waters of the 100-year flood attain a maximum depth greater than one <br /> <br />and one-half feet be defined as a high hazard area, and areas with depths <br /> <br />less than this be <br /> <br />called 10w hazard areas. <br />I .5'!wdwes <br />and new residenwmAlocated <br /> <br />Development is prohibited in <br /> <br />high hazard areas <br /> <br />within the low hazard area <br /> <br />must have all habitable living quarters (first floors) constructed with a <br /> <br />minimum freek,..d <br /> <br />of one foot above the 100-year flood water surface <br /> <br />elevation. No basements are recommended for these structures and if flood <br /> <br />velocities are 3 feet per second or greater, floodproofing is required. <br /> <br />The Floodway Concept defines an area of the floodplain based. on a rise <br /> <br />uilhWIGI <br /> <br />The floodway must be kept free of encroachment such <br /> <br />that the 100-year flood is conveyed without substantial increases in <br /> <br />flood depths above the existing depths. <br /> <br />As a minimum standard, The <br />0.. <br />increase be limited to 1.0 <br />^ <br /> <br />Board's <br /> <br />I <br /> <br />1980 model regulations suggest the depth <br /> <br />foot <br /> <br />'. <br />I <br /> <br />If'istl. J <br /> <br />provided hazardous velocities are not produced. There are several <br /> <br />methods used in floodway computations. The most common method is computed <br /> <br />on the basis of equal conveyance reduetion from each side of the floodplain. <br /> <br />The area outside of the floodway, where development is allowed, is called <br /> <br />I <br /> <br />the "fringe" area. -:::::::> <br />.- -------. <br />(-New ~esidential construction or substantial improvement of existing <br />~ fh.. fv\Y\'lo a~ <br />homes must have the 10west habitable floor be at least J.O feet above the <br />(\. <br /> <br />elevation of the, 100-year flood. Non-,residential construction must meet <br /> <br />the same standard or be flood proofed to tha.t level, The concept of the floodway <br /> <br />l <br /> <br />has been adopted by the National Pload Insurance Administration. <br />