Laserfiche WebLink
<br />II <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />! I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />3.3 Surface Water <br /> <br />The active surface water sources and drainage ways in the vicinity of the tunnel include the <br />Colorado River, Plateau Creek and Ashbury Creek in addition to the apparently ephemeral <br />drainage ways located to the east of the east tunnel portal, along the Plateau Creek Canyon and <br />several other ephemeral minor drainage ways along the western bank of the Colorado River. <br /> <br />In the project area Plateau Creek flows in a northwesterly direction and drains into the Colorado <br />River. It can be characterized as a small river with the average flow channel width varying from <br />40 feet near the eastern pipeline terminus point to 140 feet at the point of its confluence with <br />Colorado River. The average water depth at the point of confluence with the Colorado River is <br />estimated to be 2.5 feet. The flow characteristics of Plateau Creek are presented on Table 3.1. <br /> <br />In the vicinity of the project area, the Colorado River flows in a southwesterly direction. The <br />Grand Valley Diversion Dam is situated approximately 1500 feet upstream from the point of <br />confluence with Plateau Creek. This diversion dam was built during the 1920's to divert water to <br />the Highline Irrigation Canal. The main flow channel of the Colorado River at the proposed <br />upstream pipeline crossover location is approximately 250 feet wide with an estimated water depth <br />of 3 to 4 feet. It appears that the historical flood plain in this area is approximately 400 to 500 feet <br />wide. The measured flow rate during the monitoring period of October 1988 to September 1989 <br />varied from a low of approximately 1400 cubic feet per second (cfs) to a high of approximately 5500 <br />cfs. The low flow occurred during the month of January and the high flow took place during month <br />of June. Based on historical flow information for the Colorado River it appears that the flow is <br />relatively low during the cold weather months of December, January, and February. The flow rate <br />increases to its highest during the months of May and June which corresponds to snow melt at high <br />elevation in Colorado. The flow rates once again decrease during the summer and fall months. A <br />more detailed summary of flow characteristics in the Colorado River are presented in Table 3.2. <br /> <br />3.4 Property Ownership <br /> <br />Research was conducted at the Mesa County Assessors office to determine the ownership of <br />properties along the proposed pipeline route and the new tunnel. The results of this ownership <br />search are presented on Figure 3.2. The proposed tunnel alignment is on Federal land managed <br />by the Bureau of Land Management. The land ownership along the proposed pipeline route is <br />more complicated with sections managed by the State of Colorado as well as Federal Land managed <br />by the Army Corps Of Engineers; the Bureau of Reclamation; and the Bureau of Land <br />Management. In addition, property controlled by the Denver and Rio Grand Railroad will be <br />impacted. <br /> <br />9 <br />