1. The object of bushing is to form a silt berm and thus prevent or stop the falling in of the banks.
2. The branches must be thickly packed in order that the water among them may become still, and also in order that they may not be shifted by the stream. If thickly packed, the pegs required will also be fewer. Most of the branches should be leafy and freshly cut, but, mixed with these, there may be a proportion of kikar or other leafless branches. Frequently it is possible to utilise jungle trees of small value, bushes, scrub jungle, or even long grass.
3. Except when the bushes are to be very small or the length to be bushed very short, the proposed line for the edge of the berm should be marked out by long stakes driven in the water at fairly close intervals. Otherwise the work may be badly done and the berm formed imperfect and out of line.
4. As the berm formed is not likely in any case to be perfectly straight, and as subsequent additions to it will be difficult, while trimming it will be easy, the bushes should extend slightly beyond the line of the proposed berm. Care should be taken that the lower branches, which cannot be seen when once submerged, are long enough.
5. The branches should be piled up to above water-level, so that, as they settle, they will assume the position desired, but to lay them high above full-supply level on the slopes is useless and wasteful. If the pegs have to be driven at a high level, the branches should be attached to them by thin ropes or twine. Long pegs standing up high above the ground are also wasteful. The pegs should as far as possible be kept in line and their heads at one level.
6. If bushing is begun during low supply, it need not, at first, extend up to full-supply level. More branches, freshly cut, can be added as the supply rises. In any case it is generally necessary to make some additions to bushing from time to time, and this should be explained to contractors and others when fixing the rates.
7. If the trees from which branches are cut are in desirable places, the branches should be cut with judgment; but where trees are in places where they should not be (e.g., on the inside slopes of the channels), all the branches may be cut off. The trunk may be left temporarily in order to supply more branches.
APPENDIX F.
ESCAPES.
(See [page 9].)