At the end of main canal or to allow escape of the silly water into the waste channel and then to natural drain during rainy season escapes are provided.

Irrigation structures constructed to escape extra water from the canal into some natural drain or nallah is called canal escape. They are located at 5 to 10 km c/c along the length of major canal near the natural drain.

Function : The canal escape is constructed for the purpose of wasting some of its water.

A canal escape is a structure constructed on an irrigation canal for the purpose of wasting some of its water. Depending upon the purpose, there can be three types of escapes:

1) Canal scouring escape

2) Surplus escape, and

3) Tail escape

The sourcing escape is constructed for the purpose of scouring-off excess silt from time-to-time. Escapes are also constructed to dispose off excess supplies of the parent channel. Excess supplies in the canal take place either during heavy rains or due to the closure of canal outlet by the farmers. In this case, the escapes save the d/s section of the canal from overflow of banks.

Escapes are thus essential safety valves for the canals, and should be constructed at intervals. The canal leading the surplus water to a natural drain is known as escape channel. The capacity of escape channel should not be less than 50% of capacity of the parent channel at that point. A canal surplus escape may be weir type, with the crest of weir wall at F.S.L of parent canal bed level [Fig. 6.17 (a)]. A tail escape [Fig. 6.17 (b)] is provided at the tail end of the canal, and is useful in maintaining the required F.S.L at the tail end. The structure is weir type with its cres level at the required F.S.L of canal at its tail end.

Purpose or Objective of canal escapes :

1. To remove surplus water from an irrigation channel into a natural drain.

2. To avoid damage to the channel by surplus water.

3. To provide the safety valve of canals.

4. It saves the d/s section of the canal from overflow of banks.