Drtginof 



usefulness of beaver ponds. The easy rain of two 

 days ended in a heavy downpour a deluge upon 

 the mountain-side a mile or so upstream. There 

 was almost nothing on this mountain either to ab- 

 sorb or delay the excess of water which was speed- 

 ily shed into the stream below. Flooding down 

 the stream's channel above the beaver pond, came 

 a roaring avalanche of water, or water-slide, with a 

 rubbish-filled front that was five or six feet high. 

 This expanded as it rolled into the pond, and 

 swept far out on the sides, while the water-front, 

 greatly lowered, rushed over the dam. A half a 

 dozen ponds immediately below sufficed so to 

 check the speed of this water and so greatly to 

 reduce its volume that as it poured over the last 

 dam of this colony it was no longer a flood. 



The regulation of stream-flow is important. 

 There are only a few rainy days each year, and 

 all the water that flows to the sea through river- 

 channels falls during these few rainy days. The 

 instant the water reaches the earth it is hurried 

 away by gravity, and unless there are factors to 

 delay this run-off, the rivers would naturally 

 contain water only on the rainy days and for a 



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