Canal water management: Case study of upper Chenab Canal in Pakistan

Increasing world population requires that crop production from irrigated areas needs to be enhanced by as much as 40% by the year 2025. This necessitates that the canal water management system be revisited and possible improvements suggested and implemented. The daily reference evapotranspiration for the Upper Chenab Canal (UCC) is estimated using the Penmann–Monteith equation 2000. Meteorological data of Sialkot station has been employed on a daily basis for a period of 8 years (1999–2006). The crop water requirements have been estimated using reference evapotranspiration, crop coefficients and cropping periods for different crops cultivated according to existing cropping pattern. Crop staggering has also been incorporated into the study. The comparison of actual canal water supplies and crop water requirements indicated an annual shortage of more than 40%, which may reduce slightly if allocated water supplies according to the Water Apportionment Accord 1991 can be ensured. The maximum deficit is 320 m3 s−1 and occurs in the month of August. This shortfall is normally met by pumping low‐quality groundwater, which is increasing secondary salinity in the area. Possible options for better water management in the UCC command area to optimize crop yields are presented, and it is recommended to look into demand side management including canal lining and on‐farm water management practices.