62 



THE IRRIGATION AGE. 



half a mile of the cut, were never preven- 

 ted from making all the examinations and 

 measurements they chose, and they never 

 discovered it; for they offered no evidence 

 of any extra flow in the cut or extension 

 during the time the wells were falling. If 

 there had been any such increase they 

 would certainly have known it and meas- 

 ured it, for they were prepared with all 

 other measurements. 



PROVEN BY WELLS. 



The case was clear enough to me and the 

 other engineers engaged on the investiga- 

 tion, but we decided that it was too impor- 

 tant to rest on any opinions or presump- 

 tions. So we bored a line of wells toward 

 the right corner of the plaintiffs land and 

 another toward the west and joined them 

 together in a large triangle, from the cor- 

 ners and sides of which we ran out some 

 spurs. There were some fifty in all, cover- 

 ing the ground between the cut and the 

 land of plaintiffs very thoroughly. The 

 level of the water in all the wells was then 

 taken with care and the whole plotted. It 

 was found that the curve made by the cut 

 ran out in about two hundred and fifty feet 

 and at three hundred became imperceptible 

 to the most careful levelling. From there 

 to the land of the plaintiffs, over seven 

 hundred feet to the nearest, the surface of 

 the water sheet was a perfect plane corres- 

 ponding to the slope of the country the 

 same as elsewhere in the valley. The low- 

 ering of the wells must have been from 

 failure of the supply, though why it should 

 fail in just that way is a mystery that will 

 never be solved. The water level was af- 

 fected all over the valley by the series of 

 dry years but nowhere else was there any 

 such astonishing coincidence as here. 



The profile shows the cut and flume lying 

 in a trough of depression with the sheet of 

 water rising again on the other side and con- 

 tinuing on the slope of the country. This 

 we proved with^wells beyond question and 

 in one place'where there was a little side 

 flume about'100 feet away the water level 

 between them was two feet above that in 

 either flume. The large flume and cut 



does not drain but merely taps the moving 

 sheet. Its effect is gone inside of three 

 hundred feet. Its effect is merely to low- 

 er the sheet within those limits and this it 

 does with a slope that forms a cone of de- 

 pression around it. 



The conclusion is that where the water 

 supply is large and steady through a large 

 amount of porous material it cannot be re- 

 duced more than so much by anyone drain. 

 Hence in many cases there is much more 

 water in an underground supply th;m \vc 

 would expect to find. Water may also es- 

 cape its influence on the sides and in many 

 kinds of material need not be very far 

 from the drain to do it. We see exactly 

 the same results in a canal I have been 

 building on the Mojave river though we 

 have not tested the matter with wells. It 

 is plain enough in other ways, such as large 

 flowing lagunas a short distance above, 

 standing at the same level as before, 

 though an underground flume has been 

 drawing over five hundred inches for near- 

 ly two years and twice the amount is strug- 

 gling to enter the fluriie but. cannot be- 

 cause the bottom which was at first put in 

 to save any question of scour has not yet 

 been taken out. 



If however the supply is a large station- 

 ary sheet an increase in the number of 

 drains will only hasten its end. Such is 

 the nature of too much underground wa- 

 ter. It is not perfectly stationary but very 

 nearly so and the supply is very light. 

 More drains may only cost more money 

 without getting much more water. The 

 rate of passage of water through gravel 

 and sand is vastly overestimated and great 

 care should be taken in investigating the 

 conditions of such a project. But where 

 found in a sufficient supply from an ample 

 water shed and on a good drainage line 

 through good* material an underflow will 

 surpass the surface flow as a steady source 

 of supply as much as irrigation surpasses 

 rain. California has now proved that be- 

 yond possipility of escape. 



