CLASSIFICATION IN EELATION TO WATEB EESOUECES. 169 



V. Water supply: 



1. General description of drainage area. 



2. Actual records if available, showing maximum, minimum, and mean 



discharge for each month, also absolute seven-day minimum for 

 the year. 



3. Storage already developed. 



4. Storage possibilities : 



(o) Location of reservoir sites. 



(&) Height of dam. 



(c) Capacity of reservoir. 



5. Prior water rights above and below power site. 



6. Ice conditions during winter months : 



(a) Without storage. 

 (6) With storage. 

 VI. Possible power development : 



1. Horsepower at wheel shaft (without storage). 



2. Horsepower at wheel shaft (vrith storage). 

 VII. Cost of power development: 



1. Cost of diversion or forebay dam. 



2. Cost of canals. 



3. Approximate cost of complete installation per horsepower devel- 



oped: 

 (a) Without storage. 

 (6) With storage. 

 VIII. Market for power : 



1. Present. 



2. Future. 



3. Length of transmission lines, etc. 

 IX. Suggestions and recommendations: 



1. Eelative to lands withdrawn. 



2. Relative to other public land which has or may have value for devel- 



opment or transmission of power. 

 X. Appendixes : 



1. Water-supply records. 



2. Maps. 



3. Pictures. 



Before entering upon field work the hydraulic engineer should 

 collect all available topographic and hydrometric data relating to 

 the stream under investigation. For many streams the topographic 

 data may be obtained from the United States Geological Survey 

 topographic sheets, the United States Land Office township plats, 

 county and other maps, or railroad location surveys and profiles. 

 Study should also be made of the precipitation records collected by the 

 United States Weather Bureau and the river-discharge records made 

 by the United States Geological Survey and by private citizens. 

 After obtaining in advance as much information as may be available, 

 the engineer proceeds to the field. His instrumental equipment 

 usually consists of hand level, steel tape, aneroid barometer, com- 

 pass with sight alidade, and camera. In some investigations it is nec- 

 essary to carry a current meter. These instruments and the notes, 

 maps, and other data procured in advance, together with a map or de- 



