Laserfiche WebLink
<br />RECOMMENDATIONS <br />We are confident of our calculations because they are based on current topographical data, <br />and were calibrated with the Dolores River flow measured at the USGS gage at the time of <br />our topographical surveys. <br />Based on our analysis and having used our current field data to verify the more <br />theoretical USACE simulations of 1978, we feel that the 1978 report is seriously <br />inaccurate. Apparently a major portion of the inaccuracy stems from faulty <br />topographical maps used in the report. Thus we recommend that the entire <br />relevant portion of the Dolores River and floodplain be carefully remapped to <br />obtain more accurate and current Information for evaluating the Impact of the <br />gravel pits at the Line Camp on flood flows in the river. <br />There is additional urgency to the recommended resurvey because we have observed that <br />about 2 feet of topsoil has been removed from the floodplain of the Line Camp recently, <br />causing all of the gravel pits to now be within the area of a 100-year flood, although the <br />permft for the gravel pits indicates that they would only be partially covered by the flood. <br />Also high earthen berms have been constructed on the floodplain near the gravel pits, <br />creating a potential danger for nearby residences when Spring floodwaters come down the <br />valley. <br />These inaccuracies in the USACE report are a serious matter because the flooding and <br />course of the Dolores River might be drastically altered by the Line Camp gravel pits. The <br />consequences of these inaccuraces might mean that: <br />(1) large and damaging floods occur more frequently than the USACE estimated for <br />this reach, <br />(2) that the Line Camp pits would be completely inundated during the 100-year <br />flood and even during smaller floods, and <br />(3) that the overbanking river flow would move at velocities higher than the USACE <br />estimated in their 1978 report, thus leading to greater risk of erosion and of shifting in the <br />river course. If the river were to shift its course during large floods, it could pose serious risks <br />to homes, property and life downstream of the Line Camp gravel pits. <br />~~.'~6' <br />~~~ ~; <br />~ ~ :~+ <br />~ d~kg <br />~~V <br />Dolores River 6 9/72/02 <br />