PAPERS ON GEOLOGY AND GEOGRAPHY 209 



maps are available, new construction and improvement 

 of existing routes can be accomplished without preliminary 

 surveys. 



One resident railway engineer estimated such saving in 

 a short piece of railway work in Ohio at $85,000.00. The 

 map cost was $4,000.00. Another railway engineer con- 

 siders that hundreds of thousands of dollars are annually 

 spent and much of it absolutely lost through lack of having 

 the country mapped. This loss rests upon the public in 

 capitalized costs. 



5. Use of Water Resources. 



A rational utilization of water for irrigation, municipal 

 supply and power development, depends upon a knowledge 

 of total annual yield of the stream which is to serve as the 

 source of supply, the daily variations in flow, and the 

 practicability of constructing reservoirs of sufficient 

 capacity to store the water until needed for use. Many 

 projects involve the construction of canals, channels or 

 reservoirs. All these problems necessitate a broad com- 

 prehensive knowledge of the topography of the catchment 

 basin. Other problems call for a map of the topography 

 of dam sites, reservoir sites, canal lines, and the configu- 

 ration of the irrigable lands. 



In order to develop intelligently the water-power re- 

 sources of a state, it is first necessary to know what those 

 resources are. Before a final analysis of such water-power 

 resources can be properly formulated, the greater part of 

 the state should be mapped topographically. As only one- 

 third of Illinois has been mapped, we cannot yet make 

 adequate plans for our own water-power development. 



6*. Drainage. 



In order to dispose properly of surplus water in swampy 

 and flooded regions, it is necessary to know the extent and 

 slope of the land to be drained, the area of the catchment 

 basin yielding water into the drainage system and the lo- 

 cation, slope and capacity of the ditches for reclaiming 

 such land. In Illinois there are about 1,150,000 acres sub- 

 ject to overflow, and additional area of the State is subject 

 to betterment through drainage. 



