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. ~ ~.. ~. ~~1 . In addition, records of the eight transtnountain diversions from the Colorado, Michigan and Laramie River Basins are available throughout the period of study. Records of canal diversions above the "Cache la Poudre River at Mouth of Canyon near Fort Collins" gaging station were obtained from the Water Co~ssioner of District No. 3. Correlations were used to expand the aw..:tlable str~-flOll data to cover the entire study period. The p:::i.re.ry correlation was made . using the Elkhorn gage 1n th the con~urrent records of the two Rustic gages. The I~ountain Supply AJ;:~ The headwaters of the Cache 1a Poudre River and the South Fork Cache 1a POudre are centered high in the Mumn:r.r Range of Colorado I s Rocky Mountains. Hauges Peak, 13,560 feet, in Rocky Mountain National. Park is the highest point in the drainage basin, . Much of the runoff of the Cache la Poudre basin results from the melting 01' snow accumulated during the winter at the hiBher ele- vations. At the Idylwilde site, 80 percent of the average annual runoff occurs in May, June and July. Recorded discharge during spring runoff reached a maximum of 3,610 cfs \/hUe m:1.nimums of 15 to 20 cfs have been recorded during the winter. An average of 189,500 acre-feet of water nOlls past the Idy1wilde site each year, ranging from 109,000 acre-feet in 1954 (estimated), to 263,400 acre-feet in 1957, (recorded). The drainage area of the North Fork of the Cache 1a Poudre comprises 566 square m:1.1es extending northward into Albany County, Wyoming. The area consists mainly of: forested and grass-covered foothills. The historic annual runoff of the North Fork drainage, adjusted for transmountain imports and the North Poudre Canal di-,ersions, averages 61,400 acre-feet. The North Fork area occa- sionally produces f'lash floods which have high peak discharges and comparatively low volumes. Maximum recorded discharge in the North Fork is 6,800 cfs, although an estimated peak discharge of 20,000 cfs occurred in 1904. There are eight transmountain diversions that import annually an average of 42,200 acre-feet of llll.ter into the Cache la Poudre &,:;10. Tile six trans mountain diversions located above the Idylwilde site import a yearly average of 39,200 acre-feet. These are the Grand River Ditch diverting from the Colorado River; the Cameron Pass . 13