Page 24

estimated to average 5,100 acre-feet annually. Of this amount, it is estimated that the Paria River contributes about 4,475 acre-feet annually. The Paria River enters the Colorado at Lees Ferry, about 15 miles downstream from Glen Canyon Dam site and about 40 miles upstream from the Marble Canyon site. Owing to the small capacity of the Marble Canyon Reservoir and to the fact that it would extend upstream to the tailwater of Glen Canyon Dam, this inflow of sediment becomes important from the standpoint of the prospective life of usable reservoir capacity. The accumulation of sediment in Marble Canyon Reservoir also would affect the tailwater elevations and production of power at the Glen Canyon Powerplant, and decrease the usefulness of the recreational facilities presently being constructed at Lees Ferry. Paria Dam and Reservoir would curtail this detrimental deposition of sediment by storing the major portion of the Paris River's sediment load. The reservoir would store 235,000 acre-feet of sediments which otherwise would be deposited in Marble Canyon Reservoir. The dam--The Paria River Dam site would be located in a gorge section of the Paria River, about 23 miles above its confluence with the Colorado River, and immediately downstream from the junction of Buckskin Gulch. The location, as shown on Drawing No. 788-300-61, is at the Utah-Arizona boundary line in the rugged terrain typical of that section of the country. The type of dam would be a concrete arch plug in the inner gorge, flanked by curved gravity-type sections at the abutments which flatten out from the gorge. Drawing No. 788-D-7 shows the dam section and the area and capacity curves. 24Epson Perfection 4870 Photo, 400 dpi, 8 bit, 14,395,392 byte