650 ECONOMICAL ASPECTS 



(3) Rainfall, Temperature and Evaporation. The maximum, 

 minimum and mean annual rainfall as recorded at the nearest 

 stations maintained by the Meteorological Service should be 

 discussed, being utilized in estimating the run-off if stream-flow 

 records are not to hand. Temperature and evaporation records, if 

 available, should also be fully considered. 



(4) Storage Already Developed. If storage is already in opera- 

 tion in the river basin above the site, a full discussion of the same 

 is required under the heads of location; owners and operators; 

 date of installation; area and volume of reservoir and of tributary 

 drainage basin; description and condition of dam and structures; 

 effect on natural run-off conditions, actual experience since being 

 placed in operation covering date, time of filling and emptying 

 reservoir; gauge records if available (to be attached in full in 

 appendix); method of control; photographs, comments, etc., etc. 

 Copies of plans of structures are to be secured if possible. 



(5) Storage Possibilities. The question of storage possibilities 

 and locations on the upper waters should be covered as thoroughly 

 as the conditions of the inspection, and the detailed instructions 

 issued therewith, may be required. If a visit is made to any lakes 

 in the upper basins, the general elevation of the banks of the same 

 relative to the water service should be recorded, with notes as to 

 what flooding would result if the lakes were raised to various 

 definite limits. When the reservoir is in a surveyed district the 

 approximate land flooded should be given in sections and quarter 

 sections. 



At the outlets all the conditions affecting the construction of a 

 dam, and the type of structure advisable, are required. This will 

 include foundation conditions; height and character of banks; a 

 section across the river at the pcint selected for the dam carried 

 sufficiently far up the banks to cover all possible limits to which it 

 may be advisable to hold the lake surface. 



A profile should be secured of the water surface from the lake 

 outlet to the dam site. Should there be a possibility of securing 

 storage by means of dredging or otherwise clearing the outlet, a 

 profile should be obtained of the water surface, and, if possible, 

 of the river bed from the lake to a sufficient distance below the 

 dam site; any other field information necessary to determine what 

 is involved in the construction of a dam and in the operation of a 

 storage reservoir is also required. 



