IRRIGATION AND DRAINAGE INVESTIGATIONS. 35 



(4) Protection and reclamation of tidal lands. 



(5) Protection of low lands in irrigated regions from seepage 

 water from higher lands, and from the use of ground water, due to 

 heavy irrigation or seepage water. 



The Avork of this Office is not to construct drainage works, but to 

 investigate and exj^eriment as to methods where these have not been 

 worked out ; to give information as to methods, where landowners are 

 not informed ; to demonstrate the advantages of drainage where there 

 is doubt as to its efficiency; to make surveys and plans where the 

 benefits will be so widely diffused as to justify the expenditure of 

 public money in their aid ; and to make studies and give advice as 

 to ways of organizing landowners and levying charges to meet the 

 expense of drainage works. 



Much work has been done in the way of assisting engineers to pre- 

 pare plans and to unite the people to carry them out. The combined 

 acreage of drainage districts in which such assistance has been ren- 

 dered during the last three years is approximately 300,000 acres. 

 Such service has been greatly appreciated, and there is reason to 

 believe that it has been instrumental in securing better plans and 

 more harmony in their execution. The engineers are often greatly 

 benefited by assistance of this kind not only in the specific work on 

 hand, but in other projects which come to them in their practice, so 

 that the work of this Office reaches much farther than the district 

 where the advice is given. 



Preliminar}^ drainage surveys and general plans have been made 

 in a number of instances where large areas are involved. This was 

 the case in Clay County, S. Dak., where plans for the main drainage 

 of 70,000 acres of bottom lands were made and recommendations 

 given which resulted in needed amendments to the State drainage 

 law and later in the organization of a drainage district under its 

 provisions. The same was done in a more extended and complete 

 manner in four counties in North Dakota during the past season, the 

 counties paying half the cost of the survey. 



The leveeing of streams for the protection of the bottom land from 

 overflow is a work of similar magnitude. This work has been char- 

 acterized by many failures, and this Office has made careful investi- 

 gations to determine the causes of breaks in levees and the best meth- 

 ods of relieving the inclosed areas of their surplus water. The last 

 annual report of the drainage work of this Office contains much 

 valuable information on this subject and recommendations as to the 

 construction and protection of levees under ditl'erent stream and soil 

 conditions. 



In the Kankakee Valley, in Indiana, there is an area 9 miles wide, 

 extending from Momence, 111., to South Bend, Ind., which needs 

 drainage. It is reported that more than $500,000 has been expended 



