CCEUR D'ALENE WATERS AS A MEANS OF IRRIGATION. 41 



In the remarks presented in this report upon the configuration of the 

 Cceur d'Alenes it has been seen that the whole area is contained in an 

 inclosed triangle, with an opening that permits the drainage to How 

 into one of the direct tributaries of the Columbia, and that Lake Cceur 

 d'Alene, into which all the waters of the Cceur d'Alene basins are 

 poured, is situated in this opening or gap. Now, if we desire to take 

 the waters of this region and conduct them upon the plains for irriga- 

 tion purposes we are limited to two courses. One is to divert the 

 rivers, before they enter into Lake C<eur d'Alene, through artificial 

 channels into the plains areas, the other is to take the water directly 

 from the lake. In either case the ultimate outlet must be through the 

 natural gap in the Couir d'Alene triangle, for there is no place where 

 an excavation through the inclosing ridges can be made at the proper 

 level. 



At the outset we are confronted by the prime difficulty of the under- 

 taking. The surface level of the water in Lake Cceur d'Alene in its 

 medium stage is given by various authorities at 655 meters (2,148 feet) 

 above the sea. Now, the plains region of the Columbia Liver basin is 

 very far from being a level expanse. On the contrary, it is a very 

 undulating region, with a sort of crest line that stretches from the 

 northwest to the southeast. The course of this is tortuous and lies 

 nearer to the verge of the eastern slope than the western, making that 

 by so much the shorter. Both the eastern and western slopes are 

 intersected by a great number of rocky canyons, the Coulees. The 

 crest line exceeds in many places 010 meters (3,000 feet), and a great 

 deal of the eastern slope will average not less than 7:20 meters (2,350 

 feet), excluding the stream valleys. To bring the water of Lake Coeur 

 d'Alene to this plateau at the necessary height to irrigate the uplands, 

 which have most need of it, would necessitate a dam sufficiently high 

 to raise, the water level in the lake more than 50 meters (184 feet) above 

 where it stands now. Even then it would not suffice to reach the 

 highest and most arid lands of the plateau. Nor would the difficulties 

 of the work end here. The contour line which joined the raised level 

 of Lake Coenr d'Alene and the plains would be exceedingly tortuous. 

 To conduct the water along this level, miles of rock cutting or high 

 aqueducts would be required. 



Another plan is presented, that of taking the water from one of the 

 rivers which empty into Lake Cceur d'Alene. Each of these has a 

 long slack-water portion nearly at lake level. To obtain sufficient head 

 we should be compelled to go far above this portion of the rivers. 

 Omitting all considerations regarding the riparian rights of owners of 

 property below the point from which the water was taken, we will con- 

 fine ourselves to the physical features. To obtain the elevation of 720 

 meters (2,302 feet) without a dam would necessitate going up the valley 

 of the South Fork a distance of 20 kilometers (13 miles) above the 

 slack water. The configuration of the country is such that it would 



