Suppose take wheat crop for example, let us say it requires a 60 cm of water in a total period of about 240 days (for a given area of field) thus giving an average outlet factor of 3456 hectares/cumec. But kor depth of wheat is 14 cm in about 4 weeks which gives an outlet of 1728 hectares/cumec. Therefore it is clear that for a given area (A) outlet factor of 1728 is very much more than 3456. Hence kor demand should be given importance while designing irrigation canal.

While fixing capacity of a canal main important that should be kept in mind is keenest demand, but not average demand. For instance, let rice require 160 cm of water during 320 days which gives an outlet factor of 1728 hectares/cumec. (i.e D = 864B/? = 864 x 320 / 160 = 1728).

Total depth of water needed = 80 cm
Period for which water is needed = 20 days
Duty of irrigation water = (864B/d) = (864 x 20 / 80) = 216 hectares/cumec
(a) Given 20% losses in watercourse
= 216 x 0.8 = 172.8 hectares/cumec
(b) Given 10% losses in head of distributary
= 216 x 0.9 = 194.4 hectares/cumec.

Area of field to be irrigated = 5 hectares
Duty of water for crop = 432 hectares/cumec
Discharge required for crop is = (5 / 432) = 1/86.4 cumec
Volume of water lifted per second = 1 / 86.4 cumec
Therefore, weight of water lifted per second = (1 / 86.4) x 9.81 = 0.1135 KN/sec
(unit wt. of water = 9.81 KN/m₃)
Maximum static lift of pump = 4 metres
Work done by pump in lifting water = 0.1135 x 4 = 0.454 KWatt
The input of pump = (0.454 / 0.735) = 0.62
(1 metric H.P = 0.735 KWatt)
Output H.P of pump = (input/?) = (0.62 / 0.5) = 0.31 H.P.

Total depth of water required = 90 cm
Useful rainfall = 20 cm
Extra water depth needed after useful rainfall = 90 ? 20 = 70 cm
Period for which water is needed = 15 days
Duty of irrigated water (?) = (864B/d) = (864 x 15 / 70) = 185.14 hectares/cumec.

Given G.C.A = 2000 hectares
Now C.C.A = 2000 x 80 / 100 = 1600 hectares
Intensity of irrigation for sugarcane = 30%
Area to be irrigated under sugarcane = 1600 x 30/100 = 480 hectares
Intensity of irrigation of paddy = 50%
Area to be irrigated under paddy = 1600 x 50/100 = 800 hectares
Duty of sugarcane = 850 hectares/cumec
Duty of paddy = 1900 hectares/cumec
Discharge for sugarcane = 480 / 850 = 0.565 cumec
Discharge for paddy = 800 / 1900 = 0.421 cumec
Now total canal capacity at head of watercourse is = 0.565 + 0.421 = 0.986 cumec.

The water depth will be multiplied by crop area which is required in this interval, so as to give volume of water required in this interval. By dividing volume by interval, we can find out discharge needed for each interval. The summation of this will give discharge required for all crops in each interval. The canal can n be designed for maximum of se values.

In order to be more precise, intervals are kept as small as possible. Monthly water requirements studies are conducted to provide a sufficient quantity of water for irrigation. So, canal capacity is increased by 20 to 25% to meet peak demands in a month.

Area to be irrigated in Kharif season = 8000 x 60/100 = 4800 hectares
Area to be irrigated in Rabi season = 8000 x 30/100 = 2400 hectares
Water required at head of distributary to irrigate Kharif area = 4800 / 4000 = 1.2 cumec
Water required at head of distributary to irrigate Rabi area = 2400 / 1800 = 1.33 cumec
Therefore, required discharge is maximum of two = 1.33 cumec.

Now let us assume kor period of 4 weeks for Rabi and 3 weeks for Kharif crop. Also, assume kor depth of 12.5 cm for Rabi and 21 cm for Kharif crop.
Outlet factor for rabi = (864B/?) = 864 x 4 x 7 / 12.5 = 1935.36 hectares/cumec
Outlet factor for kharif = (864B/?) = 864 x 3 x 7 / 21 = 864 hectares/cumec
Area to be irrigated for Rabi season = 2400 hectares
Area to be irrigated for Kharif season = 1800 hectares
Water required for Kharif season at distributary = 1800 / 864 = 2.08 cumec
Water required for Rabi season at distributary = 2400 / 1935.36 = 1.24 cumec
Therefore, canal capacity at head of distributary is maximum of two, 2.08 cumec.