Abstract:
Water diversion mechanisms are commonly used
in the irrigation systems and this concept is older than tank
(reservoir) systems in Sri Lanka. At present, for water diversions
in the wet zone anicuts are constructed by using lifting type gates.
Anicuts are used to maintain required water level in the
upstream by releasing only the excess water to downstream. In
the lifting gate, water is allowed to flow from the bottom and this
causes high erosion in the canal. The thrust force due to water
pressure on the lifting gate makes it difficult to operate the
system and then controlling the system is a complex task. This
paper describes the construction and operation of newly
introduced flap gates and issues related to lifting gate which are
presently used for diversion process. In this analysis, conceptual
design of a flap gate with compressive arc type wall plate is
proposed to minimize use of construction materials. In the
proposed system, height of the anicut could be changed from the
top and then the water level in the upstream is not varied much
when compared with lifting gates for varying flows in the cannel.
According to the practical experiences from implemented
proposed systems, controlling of the system is much easier
compared to the conventional system.
