Maintenance plan for the Lam Nam Oon irrigation system in Northeast Thailand

Catch-up maintenance will involve emergency methods (constructing deep drains and replacing damaged lining panels), contract methods (providing surface and subsurface drainage), and force account methods, which will use resources supplied by the Royal Thai Operation and Maintenance Division. Equipment needs for these procedures are outlined and expected costs summarized. The long-term maintenance plan calls for completing all drainage facilities, eliminating 90% of all sediment sources along irrigation channels, sealing all concrete lining panel joints, periodically replacing worn-out equipment, budgeting for maintenance materials, and adhering to a strict preventive maintenance program. A key recommendation is to provide technical assistance to water user groups and to strengthen their authority to prosecute system abusers. Included are 24 tables, 27 figures, and detailed appendices on the maintenance needs of specific Lam Nam Oon irrigation structures.