Regulation of Rivers

the measures taken to improve river channels so that they can be used more efficiently in the national economic interest. River regulation ensures the creation of favorable conditions for navigation and timber rafting, the maintenance of the necessary water level at water intake works, the protection of populated areas and agricultural land from flooding during spring floods and high water, the slower movement of river sediment, and the smooth flow of water toward the openings of hydraulic engineering structures. The tasks of river regulation are carried out most successfully by the joint application of two methods: regulation of the streamflow by constructing reservoirs that store the discharge and regulation of the destructive erosive activity of water in a river channel by means of regulating structures.

The regulation of a river channel is the artificial reinforcement or alteration of the channel’s configuration and of the direction of channel-forming processes, whose intensity depends chiefly on the flow rate and slopes of the river and the type of soil that makes up its bottom and banks. Because of the different conditions under which river channels are formed (diverse hydraulic regimes, flow rates, depths), the deformations of the channel over the length of the river vary: in the upper reaches bottom erosion usually predominates, whereas in the lower reaches sedimentation prevails.

Channel regulation may be general, extending over the entire length of a river, or partial, where regulating work is carried out only along stretches. Few channels are fully regulated on the basis of a general plan because of the considerable expenditures involved. A river is said to be regulated if its channel has been stabilized, that is, if a correspondence has been established between the inflow of sediment and the river’s ability to transport it either over the entire length of the river or along stretches.

River-regulation measures also include shore reinforcement (involving bank-protection structures) and dredging.