Plate 29

WATER CONTROL AND SOIL EROSION

 

   Upper left shows how the water is controlled and the problem of the big gully forgotten. The big eroded gully is in the line of trees. The run-off which cut the gully was re-directed across the recent keyline cultivation (at right of the picture), and though flowing across it, no movement of the sandy earth took place. The water reaching the drain was then under full control and flowed to the dam.

   Upper right: The typical erosion pattern on the front of a dam wall built with granitic earths and soil covered on the back and top only.

   Upper middle: A dam on "Pakby" with the typical erosion pattern of granitic earths when there is no soil covering.

   Lower middle: Son Ken standing on the rear wall of the dam (upper right), which was covered with an inch or so of soil and received the same rainfall but has no erosion.

   Lower: An important finish to a dam wall is to cover all the wall with the soil removed from the site at the initial stages and recultivate it. Note also the two ends of the lockpipe through the bottom of this new dam.