THE CATASTROPHE AT LIMA, MONTANA. 



21 



two and a half feet horizontally. These slopes were 

 well-protected by a covering of stone eighteen inches 

 thick. 



The discharge into the canal system to be inaugu- 

 rated hereafter was through a tunnel 7x7 feet and 176 

 feet long cut through very hard conglomerate, making 

 the cutting of it very difficult and expensive. This 

 conglomerate had fissures in it, and these in connec- 

 tion with a body of dolomite, which swelled badly in 

 getting wet, caused a little caving inside of the tun- 

 nel and throwing down some obstructions to the free 

 flow of water. The tunnel should have been lined 

 inside to make it secure and give free flow of water. 

 This tunnel had a capacity of 1,500 cubic feet of 

 water per minute under the proposed pressure in the 

 reservoir. 



The company selected the right hand side, some 

 distance from the dam, for a spillway to carry off 

 surplus water to keep it down to a safe level. That 

 appears to have been simply an open cut in the 

 ground, all of which was secondary deposit, and to 

 have been an insecure affair should any great body 

 of water run through. Citizens in the valleys below 

 became afraid the dam would wash out and serious 

 losses follow. Such a hubbub was raised over the 

 dam and what they deemed impending dangers, 

 which were so thoroughly talked over as to excite 

 citizens, that an agreement was finally entered into 

 by which a few citizens and the county of Beaverhead 

 were to contribute enough to put in a new and larger 

 spillway. Only two of the board of directors were 

 residents of the state, and they for their part agreed 

 for the work to be done and to waive all claims for 

 damages they might sustain. This new spillway was 

 to be some distance farther in the hill, and to be cut 

 to a certain depth, 30 feet wide at the bottom, and 

 with a grade of one per cent., and it requires a cutting 

 about 350 feet long. The work was done by a con- 

 tractor under the guidance of J. H. Haines, sheriff of 

 Madison county, the dam being in that county. Mr. 

 Haines was not an interested party further than to 

 carry out the wishes of the people. He was not a 

 civil engineer, and pleaded ignorance of hydraulics, 

 but he did the best he knew how, and no one blames 

 him in the least for what afterwards happened. 



I* is safe to say no good hydraulic engineer would 

 ever have constructed a waste weir as this one was. 

 The earth to be cut through was made up entirely with 

 secondary deposit, and this was in layers in succes- 

 sion of hardpan or cemented gravel, sand, boulders, 

 etc. These layers had a dip up stream of seven to 

 te/i degrees, while the cut was to have its bottom 

 pitch the other way one per cent. Necessarily with 

 this grade and the head high up made a fall of 30 

 to 40 feet at its lower end or discharge, enough to 

 rapidly tear away the earth and make the plunge 

 work up stream at a greater or less speed. Had 



some of the streaks of hardpan pitched the other way 

 and been used for the bottom of this spillway it might 

 have carried a stream indefinitely. But its weak 

 point was in having the underlying stratas dissolved 

 and washed away, leaving the streaks of hardpan to 

 fall from pressure and lack of support below section 

 after section until it had washed clear back to the 

 water, and thus emptied the reservoir with a great 

 rush of waters. Nature has recorded in its history of 

 rocks the fact that Niagara Falls has gone up stream 

 many miles through the waters in the big plunge, 

 softening and washing out the softer materials be- 

 neath the rocks, leaving them to gradually split off 

 and fall from their own weight and that of the water 

 running over them, then to be pulped by the " mills 

 of the gods " and carried away. 



In the Lima dam we have the spectacle of that 

 structure as firm as ever, while off to the right is a 

 chasm 150 feet wide, 50 feet deep and 500 or 600 feet 

 long, from which the floods carried out from 1,500,000 

 to 2,000,000 cubic feet of earth, the boulders, gravel 

 and heavier portions finding lodgment below, while 

 all there has been greatly changed in appearance. 



The beautiful grassy bottom of a few hundred 

 acres a few weeks ago is now ruined, while the creek 

 flows in two streams, one each side, instead of in the 

 old channel now filled up. 



If, in construction, a good headgate of masonry 

 had been put in, and a solid flume for the surplus 

 water to run through clear down to the creek level, 

 there would have been no washout and no flood, and 

 the company would not now have a chasm more diffi- 

 cult to dam than was the one now standing firm. 



This dam was intended to hold back and reservoir 

 the rainfall of a drainage basin 100 miles long by 80 

 miles wide. The reservoir was filled to within eight 

 feet of the top of the dam when the waters broke 

 loose, and it extended up stream about 15 miles, 

 averaging one mile wide. What the plans of the 

 company are for the future is not known. Where 

 the responsibility for this flood and resulting dam- 

 ages rests is likely to be determined in the courts. 

 Certainly there are rights in equity which will be 

 contested for, and which the writer does not care to 

 discuss. If it results in a failure of the irrigation 

 enterprise to cover the beautiful valleys below, it will 

 be bad. But the lesson it has given should prompt 

 such State laws as will forever prevent as far as pos- 

 sible the recurrence of any similar future catastrophe. 

 This company capitalized at $500,000, incorporated 

 under the laws of Montana, and it is time there 

 should be laws governing and controlling such enter- 

 prises to at least the point of safety to the people, as 

 well as defining rights in equity for both the people 

 and companies, and such laws should embrace the 

 services for the State of one or more competent hy- 

 draulic engineers. 



