FLOOD06660 - Laserfiche WebLink

Home Browse Search

:'c-,' - 25 - Econauic Investigations it; ~{ ~ ~ ~, i Evaluation of flood damages and benefits, which are associated with works of improvement scheduled for installation under this plan, were based on items of current and historical record, Damage investigation and evaluation methods used in this plan comply with procedures described in the Economics Guide for Watershed Protection and Flood Prevention. Long-term projected prices (Agricultural Price and Cost Projections, 1957, by the Agricultural Research Service and Agricultural Marketing Service) were used for computing monetary damages, benefits, and operation and maintenance costs. Current (1959) prices were used to estimate structural installation costs, Federal and non-Federal costs were amortized at 2t per cent interest for 50 years, ~ ~ i' I i " Agricultural damage estimates were based on schedules obtained from landowners and operators and included about 70 per cent of the floodplain lands. These schedules covered land use, crop distribution under normal conditions, crop yields, crop production costs, changed land use because of flooding, and historical data on flooding and flood damages. Schedules also covered items related to other agricultural damages such as sediment and scour damage to fields, fence losses, and debris removal, Information regarding road and bridge d~"ages was obtained from the Maintenance Engineer, Colorado State Department of Highways, for State Highways 83 and 86 and fram the County Commissioners and County Ro&d Overseer for county roads and bridges in the watershed, , c Floodwater, sediment, and erosion damages were calculated under present conditions and under conditions that will prevail after the completion of the works of improvement for the project, ~ f ~. ?~ Agricultural damage, as evaluated, reflects the net 10ss in income to crops for the series of storms expected to occur in a one hundred-year period. Crop yields and production practices used in the evaluation were the average for the area, adjusted to flood- free conditions by the judgment of farm operators in the watershed and agricultural technicians familiar with the area, I f In the estimation of crop damages and benefits, the per cent loss of crops by flooding was developed for each month during the thunderstorm season, The per cent loss for each crop was then multiplied by the value per acre of the undamaged crop and adjusted for expected increased or decreased production cost from flooding to give the net flood damage per acre for each crop. These net damages were weighted by the per cent of land in the crop and by the storm frequency series to give a damage value per composite acre by flooding, The net damage per composite acre of floodplain lands was multiplied by the average annual acres flooded, with and without the program, to give the average annual monetary damages and benefits frorn flooGing.