THE IRRIGATION AGE. 



269 



THE LOWER YELLOWSTONE PROJECT 



Great Undertaking in Montana and North Dakota Which Means the Reclamation of 66,000 Acres of Arid Land and 



the Construction of a Canal 70 Miles in Length. 



By J. S. Conway, Engineer U. S. Reclamation Service. 



The Lower Yellowstone project comprises 66,000 

 acres in a fertile valley between the Great Northern and 

 Northern Pacific railways on the west bank of Yellow- 

 stone River. About two-thirds of the total acreage is in 

 Montana, while the remainder or northern portion lies 

 in North Dakota. 



Stock-raising has been carried on in this district for 

 about twenty-five years, and it is believed that the assur- 

 ance of a good forage crop for winter feed, combined 

 with the unlimited areas of open range available for 

 summer pasture, will make this industry, now somewhat 

 of a chance, a profitable certainty. The soil is produc- 

 tive, as has been shown in years of abundant rainfall, 

 when large crops of hay, grain, potatoes and garden 

 vegetables have been raised. Farther up the Yellow- 

 stone private irrigators have made a success of the 

 sugar beet, and there is no doubt that it will ultimately 

 be grown here. 



Construction of an irrigation system has been taken 

 up by the United States Reclamation Service as the 

 result of a reconnaissance of western North Dakota 

 made by Mr. F. E. Weymouth (now engineer in charge 

 of the project) shortly after the passage of the re- 

 clamation act. There is contemplated the diversion of 

 about 830 second feet of water from Yellowstone river 

 at a point nineteen miles north of Glendive, Mont., into 

 a canal seventy miles long extending to the Missouri 

 river, which forms the northern border of the project. 



Headgates structure, nearly completed. 



The general plan of the work is simple, consisting of a 

 low diversion dam, and a canal parallel to the river, 

 with laterals branching off to water the intervening 

 strip of land. Complicating what might seem an easy 

 problem, it must be remembered that this land is located 

 on the eastern edge of the arid belt and is subject to 

 occasional heavy rainfall in the spring, which is drained 

 off by a number of creeks crossed by the canal, necessi- 

 tating an unusual number of structures. In the case 

 of the headgates and dam, extra precautions have been 

 required on account of ice-gorges in the river, which 

 occur some seasons; and, furthermore, the upper part 



of the main canal, before the irrigable land is reached, 

 traverses a rather rough and broken country, involving 

 deep cuts and heavy side-hill work. 



To give some idea of the magnitude of this under- 

 taking before taking up a few salient features more in 

 detail, some quantities and comparisons might be 

 quoted. The amount of excavation, almost wholly in 



Concrete culvert on main canal. 



earth, approximates 6,500,000 cubic yards which, if 

 dumped in a cone-shaped heap, would cover a thirty- 

 acre field to a central height of 400 feet. One hundred 

 and forty carloads of cement, each containing forty 

 tons, will be used for mixing concrete, and if the steel 

 bars used for concrete reinforcement were placed in a 

 straight line, they would extend 150 miles. 



DIVERSION DAM AND HEADGATES. 



The diversion dam is a rock-filled timber structure 

 on a pile foundation, 700 feet long at right angles to the 

 current, and will raise low water in the river about four 

 feet. It is specially designed to resist the destructive 

 effects of ice, by having the approach on a slope of three 

 to one, while the down-stream face is ogee-shaped, with 

 a heavy rock apron immediately below. Grinding of the 

 face timbers will be largely prevented by steel straps, 

 four inches wide and one inch thick, spaced two feet 

 center to center. The location of the dam is exception- 

 ally favorable, the river channel being straight and uni- 

 form, unbroken by the many small islands which, are 

 so common a feature in its course. The west or head- 

 gate bank has a sheer height of from fifty to sixty feet, 

 while on the east bank where the ground is much lower, 

 a concrete abutment has been built, backed by a dike 

 faced with riprap and extending inland to high ground. 



The headgates structure is entirely of concrete, con- 

 taining approximately 5,000 cubic yards. The main 

 wall, parallel to the river, and the upstream wing wall 

 are gravity sections, sufficiently heavy in themselves to 

 resist the maximum effects of flood. The downstream 

 wing wall is designed as a retaining wall for earth, and 

 is heavily reinforced with steel bars. In the front wall, 



