Stages of planning irrigation projects

Planning of an irrigation project is done step by step so that only viable projects proceed to costly design and construction.

1. Identification (reconnaissance) stage: potential sites are identified from maps, field visits and existing data. Water source, command area, rough cost and benefits are assessed. Output: a list of possible projects.
2. Pre-feasibility stage: a quick study of technical, economic, social and environmental aspects. Alternatives are compared, rough designs and cost estimates are prepared, and the project is screened.
3. Feasibility stage: detailed surveys (topographic, hydrological, geological, soil, agro-economic), preliminary design, quantity and cost estimate, benefit-cost analysis (B/C ratio, IRR, NPV), environmental and social impact assessment, and institutional/financial plans. Decides whether to proceed.
4. Detailed design and tender stage: final design of headworks, canals and structures, drawings, specifications, bill of quantities, tender documents.
5. Implementation (construction) and operation stage: construction, commissioning, O&M and later monitoring and evaluation.

Planning is also viewed at levels: national/master plan, river-basin (regional) plan, and project plan.