Description of the LB and the traditional systems

 Description of the LB and the traditional systems

• The Deduru Oya left bank (LB) canal of the new reservoir will provide irrigation to both ancient tanks and new lands.
• Ancient tanks in the command area on the left bank side often face prolonged droughts, leading to the inability to cultivate crops in some years due to water scarcity.
• Water supply to the tanks follows different patterns, including drop-in take-out, where the LB canal feeds a tank from one side and collects water from the other side.
• Distribution canals are also used to supply water to the tanks.
• Initially, a lumped system analysis was conducted by combining adjacent tanks into tank groups for analysis purposes.
• However, due to varying storage levels and water receiving mechanisms, individual village tanks needed to be modeled with the central reservoir to derive optimal water allocation plans and identify vulnerable points in the system.
• The entire system, consisting of 145 distribution nodes, was modeled to develop water allocation plans and assess water resources.

The effectiveness of the stand-alone and combined systems was evaluated through simulation of the following scenarios:

1. Ancient village tanks only under normal climatological conditions.
2. New reservoir only under normal climatological conditions.
3. New reservoir only under dry weather conditions.
4. New reservoir and ancient village tanks under dry conditions.

By simulating these scenarios, the performance and outcomes of each system configuration could be assessed, considering both the presence of the ancient village tanks and the new reservoir, and varying weather conditions such as normal and dry conditions.