94 FOREST LANDS FOR THE PROTECTION OF WATERSHEDS. 



interests depend as evidence of the confidence of engineers in these structures, 

 but if he will apply their costs, particularly those of important structures in 

 Europe, 'to his proposed system the money value of safety will mount up to a 

 prodigious figure." 



A feature of this question of safety often overlooked is the depreciation of 

 the market value of property, due to its location below a dam, where failure 

 of the dam would mean a disaster of great magnitude. However safe the struc- 

 ture may be many people would not purchase property below it, and its market 

 would be correspondingly diminished. While such loss can hardly be made a 

 subject for damages, it is a real loss to the owners. 



These reservoirs being built for flood protection, the sluices must be very 

 large, so that at times they can be discharged practically as fast as the water 

 runs in. This will be necessary during periods of prolonged precipitation in 

 order to keep the reservoirs from filling too full before the danger is past. 

 This detail of construction will add largely to the cost. 



Taking everything into consideration on the most liberal basis, it is evident 

 that this system can not be built for less than $250 per 1,000,000 cubic feet. 

 The probable increase in the value of property to be condemned before the 

 system could be built and the present scale of prices of labor and material 

 make this figure a minimum. This would swell the cost of the whole system 

 to over four times Mr. Leighton's estimate, or over half a billion dollars.* 



This is not all, however. It appears that the complete development of the 

 reservoir system as proposed will take from industrial use probably 1,500,000 

 acres of land, including the lands actually overflowed, the margins subject to 

 damages, and sites for the dams and various structures appurtenant thereto. 

 These lands will be in large part, by the very fact that they lie in valleys 

 suitable for storage grounds, the best lands in the localities. Sooner or later 

 they are bound to come into agricultural use, and with proper cultivation their 

 annual net-revenue value will be at least $5. per acre. If utilized for forest 

 culture they ought to yield 500 feet board measure of lumber and 1 cord of wood 

 annually per acre. The value of the land for this purpose ought to be as great 

 as the figures just given. It thus appears that the occupancy of these lands for 

 reservoir purposes will take from the community an annual product of at least 

 $7,500,000 worth, and probably more. 



The reservoirs will store about 2,150,000,000,000 cubic feet of water. Assume 

 that this can all be utilized for water power, with the average head of 200 feet, 

 giving theoretically about 1,000,000 horsepower per year, or 1,280,000 horse- 

 power at 80 per cent efficiency. At $5 per horsepower (the bnsis for this figure 

 will presently be considered), the revenue from water power will be $6,400,000, 

 which falls short of the loss resulting from withholding the sites from pro- 

 ductive use. 



The recent failure of the Hauser Lake Dam, on the Missouri River, near 

 Helena, Mont., is a good illustration of how the unexpected may happen. Here 

 was a dam built of steel and concrete, two materials whose properties are thor- 

 oughly understood. The case was one which " ordinary engineering " might be 

 expected to hsindle successfully. The public had reason to feel confidence in the 

 structure. Yet " it fell, and great was the fall thereof," not only in the total 

 wreckage of the dam, but in the losses caused along the valley below. 



The accident affords also another illustration of the omnivorous claims put 

 forward in these days in the supposed interests of forestry. The disaster was 

 promptly cited as an example of the havoc wrought by floods in a country with- 

 out forests. The normal flood discharge of the Missouri at this point is 20,000 

 cubic feet per second ; for 1907 it was 26,000 cubic feet ; the maximum on record 

 is about 50,000 cubic feet. At the time of the accident the discharge was about 

 7,000 cubic feet. 



6 Recent examinations of certain sites, embracing nearly 70 per cent of the 

 proposed Monongahela storage, indicate that the whole Ohio system will cost 

 at lenst a billion dollars, and possibly a billion and a half. 



c The sanitary feature has not been considered, although it is one of some 

 importance. The laying bare of large areas of reservoir bottoms in the heated 

 portion of the year is objectionable, but it is not a matter affecting the element 

 of cost. Neither is much stress here laid upon the danger to the reservoirs from 

 silting up. This is not a region of heavy silt movement. In most of the reser- 

 voirs the process will be very slow, and we may safely leave to distant genera- 

 tions the task of dealing with this problem whenever it reaches an acute stage. 



