Laserfiche WebLink
<br />CONVEYANCE COSTS <br /> <br />Type of Conveyance <br />'Conventional Sewers ( 2 ft. diameter) <br />(10 ft. diameter) <br />Rock Tunnels (10 ft. diameter) <br />(20 ft. diameter) <br />Open Channels (vacant land) <br /> <br />Cost in Dollars per CFS Mile <br />$ 7,500 <br />1,800 <br />1,200 <br />300 <br />190 <br /> <br />It is apparent that the least expensive storage is in open reservoirs <br />and natural flood plains and that the least expensive conveyance is open <br />channels or in some instances very large tunnels. These two elements, <br />surface storage and open channel conveyance works,dominate systems studies <br />for larger metropolitan areas, <br />The physical works alternatives can modify the rate of movement <br />throughout the system, the usual storm sewer and flood control works, <br />or detain the excess near where it falls (upstream). The works usually <br />used to modify the movement through the system include sewers, storage <br />reservoirs, canals, improved channels, pumping plants, tunnels and <br />di kes or levees. The app 1 icabil ity and functi ons are we 11 understood. <br />Each of these works are very effective means of managing stonnwater. <br />The conveyance facilities (open channel) and storage works offer <br />opportunities for joint use of space, such as for recreation, open <br />space, wildlife habitat, conservation and other purposes. <br />One major consideration in structuring alternatives for use within <br />an urban area is the appearance, Underground storm sewers cannot be seen; <br />however, they are generally the most expensive conveyance mode. The least <br />22 <br />