Arizona weekly citizen., 1889-06-15
Irrigation Survey Instruc-
 tions,
WASHINGTON, D. O., June g. 'se.

WASHINGTON, ID. C., June g, '89.
 Professor J. w. Powell, Director of the Geological Survey, has issued instruc- tions to Prof. A. H. Thompson, Chief Topographer; c. E, Dutton, Chief En- gineer, and. the photographers of the Irrigation Survey, detailing the methods to be followed in carrying on the work In his letter to Captain Dutton, Prof. Powell says: "In each hydrographic basin it is desired to attack these pro blems: What are the available sources of water supply, and by what means may the water be most fully utilized? A Photographic basin may mean the watershed of large stream, or a small one-of a great river or one of it's tribu- taries. But whether it means trunk stream or branch of it-a questiontto be decided by the engineer-it is assum- ed that there is some form of develop ment and construction of works which may be adjudged to the best that the engineer can devise. The engineers should take no account of works which are already constructed, nor should their judgment be swayed by any opin- ion on their part as to what works pri- vate enterprise and capital are likely to undertake in the next few years. They They should rather address themselves to the question already propounded: What is the best system one which will utilize the greatest amount of water and produce the greatest amount of ir- rigation. It should not be forgotten that practical irrigation development in each part starts with a small begin ming, and involving great waste of water, and involving great waste for maintain ance; that 1t advances through success sive stages, by more costly works super ceding the primitive ones. But of these the engineer should take no account His project should embrace what is, in his judgment, the best system irrespec- tive of what IS or actually may be con structed. At the same time, his project should be practical one, involving no extravaganza of engineering, not trans cending the possibilities of attainment, and maintenance after attainment.
 ''The plans should have also a certain unity, and should contemplate a single system of works for each irrigation dis trict. If both reservoirs and canals are required the reservoirs should be, if pos sible, projected as adjuncts of the canals No doubt it will happen sometimes that the rivers alone are more than sufficient for the available land, as in some valleys of the northernmost States and Terri tories; or that reservoirs alone are pos sible, as in parts of the southernmost Territories; still in such cases, unity of plan should, so far as practicable, be kept in view.
 Engineers should seek to devise plans to secure the greatest amount of irriga- ton with the least expense, and to minimize the distribution works by which water is taken from canals and reservoirs and put upon the land. It is to be borne in mind that this survey is not primarily designed for the benefit of private parties or corporations who may contemplate the construction of works, though if they should incidentally derive benefit therefrom, it would be matter for congratulation. Its primary object IS the information of the Congress and of the State and Territorial Legislat- urers, and the guidance of future legis- ation with respect to the arid lands and the use of the natural waters. Hence 1t IS designed to spread upon good maps, and set forth in printed reports and re- cords, the facts as they exist and the possibilities which may be hoped for in there entirety. The exigencies of the service demand that the work of the en- gineers shall be commenced at an early date, in order that complete systems of irrigation can be projected and the plans reported to Congress at it's next session"
 In the general instructions for h hydrog- raphers Prof. Powell says:
 'The duties which devolve upon the photographers will be at once of high ly and scientific and practical character and will consist in Gscertaining by sys- tematic observations and measurements the values of numerous factors or quail ties which must be known in order to fully carry out the purposes of the law, which requires an investigation to the extent to which the arid lands can be redeemed by irrigation. They may be mentioned in the following order: CD Measurements of water supply (2) meas urements of the loss of water by evapor- ation; (3) the investigation of the clima- tology of the arid regions with reference to agriculture by irrigation; (4) measure ment of sediment transported by stream; (5)the duty of water; (6) collection of general information. The measurement of water supply will consist primarily in the guaging of streams The study of the climatology of the west will be mainly the work of the centeral office. as the data upon which it depends are of regional extent and most of them are collated by the signal service, whose re- cords are accessible only at Washing ton. The measurements of sediment transported is subject which must await future action. Care should be taken to ascertain the duty of water in all localities where irrigation is practic- ed whenever opportunity occurs. The following factors seem to be of prime importance: Q) Method of flowing lands; @ climate; (3) character of soil and sub soil; (4) kind of crops raised"
 Reports are to bemade monthly em- bracing full account of all operations during the month.