Regarding the ordinary maintenance work on the channels, details are given in Appendices B and C. Appendix D, reprinted from _Punjab Rivers and Works_, contains rules for watching and protecting any banks or embankments which require it. Silt clearances and berm cutting of channels have been mentioned in Art. 1. Special attention should be given to the accurate ranging of the centre line. Otherwise the channel may become crooked. The great defect in the earthwork ordinarily met with in the banks of canals and distributaries is that the clods are not broken. In consequence of this new banks are extremely liable to breach, and much trouble and expense result. Sometimes a dam is thrown across a new distributary, and the channel upstream of it is gradually filled with water, the bank being watched and leakages made good. The dam is then shifted to a place further down. In this way the banks are consolidated. When a distributary is closed for silt clearance or other work, if the head regulator has planks and a double set of grooves, it is possible to stop all leakage by filling in earth between the two sets of planks and ramming it, but otherwise it is necessary to construct an earthen dam just below the regulator. Upstream of the dam the water, owing to the leakage through the planks, gates or needles, rises to the same level as the water in the canal. Native subordinates have a remarkable aptitude for allowing such dams to break while the work in the distributary is in progress or before it is measured. Now and then the dam is wilfully cut. The remedy is to make the dam of proper strength--the top should be 8 feet wide and a foot above the water,--and to have it watched day and night. At a bend in a channel there is often a silt bank next the convex bank, and a hollow near the concave bank. The average bed level is probably very much the same as in the straight reaches. Removal of the silt bank is unnecessary, and if removed it quickly forms again. Any length of channel in which the depth of silt to be cleared is small, say ·50 foot in a large channel and ·40 foot in a small one, should not be cleared, provided its length is considerable (say 1,000 feet), and that it is not close to (say within 3,000 or 2,000 feet from) the head of the channel. Estimates should be prepared accordingly, the shallow digging being struck out. Clearing a small depth of silt merely gives contractors a chance of cheating by scraping the bed. If the watercourses at the tail of a distributary are silted, the people should be pressed to clear them. Otherwise there will be heading up of the water of the distributary, and silt deposit may result.