System Performance Analysis and Deficit Volume during Extreme Dry Weather Conditions
Understanding the performance of individual ancient reservoirs is crucial for achieving full coverage during extreme dry weather conditions. Scenario analysis conducted for the whole system reveals that even the ancient tanks would fail to meet water demands in September. The performance of these tanks varies due to differences in storage volume and command area. When relying solely on the new reservoir for irrigation on the left bank, there is a deficit volume of about 1MCM in September during an extreme dry year.
- The total capacity of the ancient irrigation tanks connected to the LB canal is approximately 9 MCM.
- Even in extreme dry conditions, the inflows to the ancient system are sufficient to compensate for the 1 MCM deficit from the main reservoir, given that water is conserved for September irrigation in the ancient tanks.
- The demand coverage for different scenarios is depicted in the accompanying figure.
- Prioritizing September irrigation can lead to achieving 100% efficiency in an extreme dry year.
- Effective water management requires collaboration between the irrigation department, responsible for issuing LB canal irrigation water, and the local management of village tanks by elected 'Jalapalaka' representatives.
