CLIMATE. The temperature of this region, as shown by the records of the Weather Bureau, ranges from a minimum of about 20 F. in the winter to a maximum of about +100° F. in the summer, the mean は being approximately +48 F. The district is more or less subject to high winds, which cause heavy drifting of snow in the winter and, in some localities, of sand in the summer. In general, however, the climate is mild and equable, and, owing to the lack of moisture in the atmosphere, the extremes of temperature are not severely felt. MEASUREMENTS OF SOUTH PLATTE RIVER. While a number of stations have been maintained and records of the discharge of the tributaries and principal branches of South Platte River have been kept, these data are not of immediate importance in connection with this investigation. It is important to know only how much water would be available at the head-gate of the proposed canal, and what the effect of its diversion would be upon the valley below. Accordingly, tables are given only for the stations at Kersey, established in May, 1901; at Orchard, established in November, 1895; and at Julesburg, established in April, 1902. While these records do not extend back so far as might be desired, they are sufficient in themselves to furnish all the information that is required concerning the flow of South Platte River along that portion which is of importance in connection with this project. In compiling these tables only such data have been included as are known to be accurate. For example, the discharge for a number of the winter months during the period when a station was maintained at Orchard is not included, owing to the fact that during those months ice gorges checked the flow of the stream to such an extent that it was impossible to determine the actual flow. The information furnished is, however, sufficient for an approximate determination of the available water supply. Second-feet. | Second-feet. Second-feet. Second-feet. | Second-feet. Second-feet. The utilization of the Pawnee Pass reservoir site has been considered in connection with other possible reservoir sites for a number of years. In the year 1894 the officers of a company, known as the South Platte Water Storage and Irrigation Company, caused surveys to be made with the view of utilizing a number of reservoir sites along the north side of the South Platte, among which those of the greatest importance are at Jackson Lake, Sanborn Draw, and the Pawnee Pass. There were also several others which it was thought might be used to advantage in connection with those mentioned, but which were of much less importance, and feasible only in case the larger sites were made use of. This company made filings in the office of the State engineer of Colorado on all of these sites, and a comprehensive plan of irrigation canals and laterals was outlined in connection therewith. These filings are as follows: Filings of the South Platte Water Storage and Irrigation Company. Sanborn Draw reservoir Orchard reservoir Jackson Lake reservoir Wild Cat No. 1 reservoir.. Capacity in acre-feet. 70, 260 5, 700 67,790 2,000 9,000 7,900 284, 696 This company has since commenced the construction of canals to take water for the Jackson Lake and Sanborn Draw reservoirs, although until the year 1901 practically nothing was done except the completion of the surveys and a little work upon the Jackson Lake inlet. In December, 1900, a preliminary examination of this region was made by the United States Geological Survey. The results of this investigation were published in the First Annual Report of the Reclamation Service (pp. 154-160). The conclusions reached at that time were that a detailed survey ought to be made to show the probabilities of reclaiming any large amount of land. It was thought that the system taken as a whole, including the Jackson Lake and Sanborn Draw and other similar sites comparatively near to the river, might be feasible, although it was thought that in all probability the entire amount of water available could be stored in the smaller sites, making it inadvisable to extend the canal so far as Pawnee Pass, which would require a canal of great length. There being no funds available at this time for making this survey nothing further was done until after the passage of the reclamation act, approved June 17, 1902, when the people dwelling along the South Platte petitioned that a survey be made for the purpose of determining the feasibility of taking water to the Pawnee Pass reservoir site, for irrigating large tracts of land, variously estimated at from 100,000 to 300,000 acres. RESULT OF PRESENT SURVEY. Charles T. Pease, a civil engineer of Denver, Colo., was directed to commence the survey of the Pawnee Pass project in August, 1902. After consultation with engineers familiar with the country and an examination of surveys already made by the South Platte Water Storage and Irrigation Company, Mr. Pease selected for his head-gate a point about 2 miles north of the town of Kersey. After a preliminary survey had been run for 13 miles, however, it was found that it was necessary for a drop of 30 feet to be made, and it was therefore decided that a new point of diversion should be selected. One was accordingly chosen about 3 miles northeast of the town of Hardin, as shown on the accompanying plat (see Pl. XX), and 45 miles of canal line were located, the survey being discontinued in the early part of December, owing to extremely cold weather and a lack of fuel and water, the ice forming to such an extent that it was impracticable to carry water either in tanks or in barrels. The survey not having been completed the report is necessarily incomplete also, and many of the estimates are mere approximations, formed from general knowledge of the country and of the difficulties. to be overcome. A very satisfactory estimate is made, however, concerning the first 45 miles of canal, so far at least as excavation is concerned, although many details have not been gone into. The last 15 miles of the 45 surveyed furnish a fair average upon which an estimate could be made concerning the remaining 45. The estimates concerning the dam are made from cross-section notes of the dam site made by R. F. Walter, of Greeley, engineer of the South Platte Water Storage and Irrigation Company. The canal covered by the following estimates has its head on the east bank of South Platte River, in sec. 24, T. 5 N., R. 64 W. of the sixth principal meridian, and runs easterly to the basin of Pawnee Creek. The estimated length of the canal is 90 miles. Two estimates for an earthen dam on Pawnee Creek have been made, the first being for a dam 100 feet high and the second for one 125 feet high. In both cases a slope of 3 to 1 on the upper side and 2 to 1 on the lower side has been given, the upper side to be riprapped. For an outlet a triple arch culvert of concrete, the three openings each being 6 by 10 feet in the clear, has been figured on. For the floor and foundation of this culvert a bed of concrete 3 feet thick and projecting 3 feet beyond the abutments has been taken. It has also been assumed that there are to be concrete aprons at both inlet and outlet and 200 linear feet of heavy riprap at the outlet, and that no wasteway will be required. The first mile of the canal passes through irrigable land, the second through a mixture of coarse gravel and sand, and in estimating the grading here slopes of 13 to 1 have been used. From the third to the eleventh mile, inclusive, the material is fine sand, which, when the surface is once broken, drifts like snow. The only vegetation is a scant growth of blue stem and dwarf sagebrush. Almost all of these 9 miles are side-hill work, and the loss of water from percolation must necessarily be very heavy. It is probable that some artificial method |