Irrigation works

by E. S. Bellasis

it may be stated that the Lower Chenab Canal is a comparatively new work, and that the duty has been steadily rising and, with the perfect watercourse system, may be relied on to reach the Upper Bari Doab Canal 234 acres per cusec in the course of time for water arriving at the heads of distributaries.

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“27. Summary of conclusions as to sufficiency of supply.—The following table shows all the foregoing results in a form readily admitting of comparison:—

Particulars.	Period.																						Average supply in river.				Deduct loss by absorp- tion.	Supply at heads of distribu- taries.	Duty calculated on 1,321,019 acres, the gross rabi area.	Duty calculated on 1,164,595 acres, the perennial area.
	1st to 15th Octo- ber.				16th to 31st Octo- ber.				No- vem- ber.				De- cem- ber.	Janu- ary.	Febru- ary.				March.
	Cusecs.				Cusecs.				Cusecs.				Cusecs.	Cusecs.	Cusecs.				Cusecs.				Cusecs.				Cusecs.	Cusecs.
Average Supplies available.
Very favourable years 1 in 4		-		21,400	15,150						-	11,850	8,626	11,200		-		13,100	21,250						-	11,811	3,414	8,397	158	139
				(13.063)	(13,063)													(13,063)	(13,063)
Ordinary years 2 in 4		-		13,900			-	11,850	10,000				7,400	7,600	9,100					-		16,500			-	9,946	2,989	6,957	189	167
				13,063																		13,063
Dry years 1 in 4	10,150				9,100				7,275				5,950	5,610	6,100				11,345				7,651				2,564	5,087	259	229
Minimum of 14 years	9,710				8,003				6,624				5,810	5,563	5,163				9,791				6,968				2,458	4,510	293	258
Requirements on average of Lower Chenab Canal for	12,045				12,135				8,729				6,715	6,267	6,503				8,625				8,155				2,564	5,591	236	208
Requirements on average of Upper Bari Doab Canal for 5 years	12,924				10,305				6,852				5,607	5,208	6,090				10,344				7,619				2,564	5,055	261	230

“The 13,063 shown in brackets represents the parts of the available supply which the canals can carry, the capacity being as follows:—

	Cusecs.
Lower Jhelum Canal	4,563
Upper Jhelum Canal	8,500
Total	13,063

“The average supplies and duty figures are based on the 13,063 cusec maximum capacity and not on the larger available supplies written above these figures where they occur.

“The above table goes to show the following:

(i) In order to utilize the large supplies available in the Jhelum River in October and March every year and in some or all of the intervening months in other years, it is advisable to give the Upper Jhelum Canal the large capacity of 8,500 cusecs proposed.

(ii) In favourable and ordinary years, that is, in 3 out of 4, the available supply will be ample, as shown by the low duties of 189 and 167 compared with those obtaining on the Lower Chenab and Upper Bari Doab Canals.