On inundation canals the water at a regulator is sometimes headed up,--all branches being partially closed--in order to give more water to outlets in the upstream reach. There are even some regulators--or rather stop-dams--constructed solely for this purpose at places where there is no bifurcation of the canal or distributary. Any such heading up should be planned out beforehand and days for it fixed, and also the gauge reading. If the water, without any heading up, rises to the needful height on the gauge, nothing has to be done. There are also places on inundation canals where the land is high and is only irrigable during floods. At such places it is usual, on some canals, to allow the people to make cuts in the bank when the water attains a certain height. Owing to the high level of the country, nothing in the nature of a breach can occur. In one canal division where the above arrangement was in force, the people used to send applications to the Executive Engineer for leave to cut the banks. This resulted in much delay. A list was prepared showing exactly where the banks might be cut, the people were informed and the formalities were much reduced. 6. =Extensions and Remodellings.= An existing canal or distributary may need remodelling for various reasons, and in various degrees. If the velocity is too high and the bed has scoured, or the sides have fallen in, it may be necessary to raise the crests of falls, or to construct intermediate weirs, or to widen the channel and reduce the depth. If the command is not good it may be necessary to regrade the channel. If silt deposit occurs, the cross-section of the channel may have to be altered, to give a better relation between D and V. If there is surplus water, extensions or enlargements of channels may be desirable and these can sometimes be undertaken to a moderate extent merely by restricting a somewhat too lavish supply to existing distributaries. If the water level is dangerously high it may have to be lowered, or the banks raised and strengthened. Sometimes it is desirable to cut off bends either to shorten the channel and gain command or because the bends are sharp and cause falling in of the banks or, if numerous, silting. In all cases the general principles are the same as for entirely new projects, but certain details require consideration.