COMPILATION OF WATER POWER REPORTS 653 



highest elevation to which there is any possibility of raising the 

 head-waters of the proposed plant. Sufficient notes should be 

 taken to plot on the said plan, with the elevations, any rock out- 

 crops which may be in evidence. Should the rock outcrop along 

 both banks of the river, the continuous line of demarcation be- 

 tween the rock and the overlying material should be plotted, with 

 the elevations, along both shore lines. The plan should also indi- 

 cate all other classes of material, such as clay, gravel, sand, loam, 

 etc., which may be in evidence together with notes as to whether 

 the site is wooded, cleared or cultivated, etc. 



Water levels (together with date of taking, and river-flow, if 

 possible) should be recorded and plotted on this plan at all im- 

 portant points, such as the brink and foot of falls and rapids, 

 marking the limits of the still water above and below. All eddies 

 and back waters should be marked and the elevation and date 

 recorded. The general line of the brink and foot of any falls 

 which will be involved in a proposed scheme of development should 

 be secured and tied in to the plan. The high- and low- water levels 

 to be expected in the tail-water of the projected power station 

 are of particular importance. Maximum high-water marks along 

 the shore should be carefully noted. 



All natural features of which advantage might be taken in 

 laying out a power-plant should be fully shown on the plans and 

 discussed in the report. 



(b) Cross-section. A cross-section of the river bed and both 

 banks along the line of the proposed dam, and sections of any 

 alternative sites which may present themselves to the engineer on 

 the ground, should be secured and plotted. Sections when plotted 

 should indicate the character of the ground surface and river bed 

 and of foundation conditions, either in evidence or assumed, 

 throughout. 



(c) Profiles. A profile of the river surface from the upstream 

 limit of the new pond created by the plant is desirable, but is not 

 essential should the circumstances of the inspection render the 

 securing of the same inadvisable. In all cases, however, a profile 

 of the river surface and, if possible, of the river bed, from a point 

 up stream from the dam, to below the tail-race of the power-plant 

 is required. A profile section through the dam, intake, head- 

 race (or pipeline, as the case may be), power-plant, and tail-race, 

 showing such governing elevations as, head-water, crest of dam, 



