83 < l\ !/>/.! V FORESTRY ASSOCIATIVE 



lor irrigation and the allied industry of stock-raising should be self evident. Timber 

 on any w:itrr>livd is the most satisfactory method of storage of water supply. Its 

 removal is always followed by violent freshets, followed by periods of extreme low 

 r in the drainage channels. 



it is certain that if the watershed of our great western plains region is denuded 

 of timber ;ms of money will ultimately have to be expended in providing, arti- 



ficially, the storage facilities now provided by the timber, and in addition we will have 

 the usual experience of loss from floods in the streams carrying the run-off from that 

 watershed, because that run-off will increase in rapidity in almost direct proportion to 

 the removal of the timber and undergrowth, which now exercise such a restraining in- 

 fluence on flood conditions. 



The success of irrigation in any country is dependent on the regularity and perm- 

 nnence of the water supply, and when that supply is dependent upon the precipitation 

 in the way of rain and snow upon any watershed, the conservation of such precipita- 

 tion, and its even discharge through the drainage channels is of vital importance. 

 Here the preservation of existing forests, or the reforesting of areas denuded of tim- 

 ber, brings forestry into close alliance with irrigation. To advance arguments that 

 water poured upon the side of a mountain containing nothing but a rocky surface will 

 run off more rapidly than if the same surface is covered with timber, brush, moss and 

 roots would seem superfluous, and yet such arguments have to be advanced in advocat- 

 ing 'the establishment and maintenance of forest reserves on watersheds providing 

 water for irrigation. 



In western Assiniboia the Cypress Hills constitute the local watershed, from 

 which all the local drainage channels receive their water supply. The timber on this 

 watershed is sparse except on the western end of the hills, and what there is there is 

 rapidly disappearing owing to cutting by settlers and the ever-recurring fires. The 

 water supply in the plains areas adjacent to the Cypress Hills is limited at best, and 

 any steps taken to preserve the present forested areas or to reforest those denuded of 

 timber must be followed by beneficial results. 



Irrigation has now passed beyond the experimental stage in the west. At present 

 there are one hundred and sixty-three irrigation ditches and canals constructed in 

 southern Alberta and western Assiniboia, comprising a total length of about four 

 hundred and seventy-five miles, and capable of irrigating 625,000 acres. With the 

 completion of the large undertaking which the Canadian Pacific Railway Company 

 have now in hand, the mileage of canals will be increased to at least seven hundred 

 miles, the irrigable area to two million acres, and the capital invested in irrrigation 

 undertakings will reach the large total of at least seven million dollars. 



This large amount of itself would justify some attention being paid to the preser- 

 vation of the forests upon the watershed upon which the whole investment rests, but 

 its importance is dwarfed beside the interests which will ultimately be dependent upon 

 a reliable and steady flow of water through these irrigation canals and ditches. 



Certainly there is no phase of the subject of forestry which at the present time is 

 of greater interest to the people of southern Alberta and western Assiniboia, anJ 

 realizing its importance, it is to be hoped that this Association will place itself upon 

 record regarding the desirability of preserving the timber on the watersheds, from 

 which the supply of water for irrigation must come. 



The introduction of irrigation on the great plains of the west will, as it has in the 

 the states and territories to the south of us, be followed by tree planting in a very 

 general manner, and in a short time each main canal and ditch will mark a line of 

 thriving timber across areas now producing nothing but grass. 



Forestry and irrigation are, therefore, closely allied, not only in the matter of the 

 nervation or removal of the timber on the area from which the water for irrigation 

 must come, but in the introduction and encouragement of tree culture in the area 

 actually under irrigation. 



