Laserfiche WebLink
<br />;R'0. <br />\"i.~',J <br />,,:..:(J <br /> <br />Approximately 1,000 feet of gravel-surfaced road <br />would be built from an existing gravel surfaced county road for con- <br />struction and operation access to the plant, The road to the inlet <br />conduit would allow construction and operation access, The road would be <br />upgraded in sections to facilitate access. Waste from the tunnel <br />could either be used for landfill at the water users treatment plant site <br />or placed in the reservoir basin, <br /> <br />(b) Ridges Basin Reservoir <br /> <br />The project's primary storsge feature, Ridges Basin <br />Reservoir, would be formed by the construction of Ridges Ballin Dam on <br />Basin Creek approximately 2 miles upstream from its confluence with the <br />Animas River. Figures A-2 and A-3 show the basin and an artist's concept <br />of the reservoir. The dam would be a rolled, earth-fill structure <br />with a height of 313 feet, a crest length of 1,600 feet, and a material <br />volume of 7,620,000 cubic yards. An outlet works with a 2,160 cfs <br />discharge capacity would be constructed in the right abutment. <br /> <br />" <br />~ <br /> <br />~~ <br /> <br />Releases of municipal and industrial water for users <br />in New Mexico would be made through the outlet works, which would have an <br />intake near the base of the dam and could consequently evacuate almost <br />the entire contents of the reservoir. The dam would not have a service <br />spillway, since the reservoir's short-term flood storage capaci ty (sur- <br />charge) would protect the dlllll against the maximum probable flood. An <br />emergency spillway, however, would be constructed about 1.5 miles north- <br />west of the dam in the saddle that separates the reservoir from the <br />Animas River, The spillway, 100 feet wide, would be excavated to an <br />elevation 7 feet below the crest of the dam so that if the outlet works, <br />through faulty operation or malfunction did not drain the surcharge pool <br />prior to a succeeding flood event, a second flood could still escape from <br />the reservoir wi thout endangering the dam. Concrete sill blocks would <br />be constructed to control erosion. The spillway would empty into an <br />unnamed intermittent tributary of the Animas River. <br /> <br />, <br /> <br />, ~~ <br />'~.o: <br /> <br />',,' <br />i", <br /> <br />The reservoir formed behind the dam would extend <br />about ,3.8 miles up Basin Creek and have a storage capacity of 280,040 <br />acre-feet, as shown on Table A-2. At the top of active capacity the <br />reservoir would have a surface area of approximately 2,270 acres, The <br />reservoir's active capacity of 130,000 acre-feet would be used to help <br />satisfy project water needs. The dead and inactive capacity of about <br />150,040 acre-feet would form the reservoir's minimum pool and would not <br />be drawn upon under normal circumstances. The large minimum pool would <br />be necessary so that the power required to pump water out of the reser- <br />voir at the Ridges Basin Pumping Plant could be held to a minimum and so <br />that gravity releases could be made through the Ridges Basin Inlet <br />Conduit to the treatment plant for use in the Durango area. The large <br />minimum pool would also benefit recreation and fishing use. The north- <br />ern, western, and southwestern reservoir boundaries would have about 15 <br />miles of fence to keep livestock from entering the reservoir area and to <br />restrict uncontrolled access to the reservoir. <br /> <br />;~1 <br /> <br />.:.~ <br />..~ <br />'-'~ <br /> <br />.,~ <br /> <br />" <br />.'.... <br /> <br />A-8 <br />