CROPWAT Irrigation Water Requirements Planning Training Course

Course overview

Irrigation planners must turn incomplete climate, crop and soil information into defensible seasonal water requirements, irrigation schedules and scheme-level water demand estimates. Errors in reference evapotranspiration, effective rainfall assumptions, rooting depth, crop calendars or application efficiency can lead to under-designed conveyance systems, unreliable irrigation service, excessive abstraction and weak budget proposals. This course enables participants to use CROPWAT systematically when preparing irrigation plans for smallholder schemes, commercial farms, rehabilitation projects and humanitarian agriculture programmes.

Participants build and validate CROPWAT projects using FAO-56 calculation principles, CLIMWAT climate records and locally available station data. They calculate ETo, crop evapotranspiration, effective rainfall, net and gross irrigation requirements, irrigation schedules and scheme water demand for multiple crops and planting dates. The course addresses practical modelling choices: selecting crop coefficients, defining soil-water parameters, representing irrigation methods, adjusting calendars for local production systems, and documenting assumptions where field data are limited.

Instruction combines guided software demonstrations with daily modelling exercises based on a realistic irrigated-command-area case. Participants progressively develop a complete CROPWAT analysis, test alternative climate and cropping scenarios, and interpret results for design and operational decisions. Each participant leaves with a documented irrigation water requirements workbook and CROPWAT project file containing climate, crop, soil and scheduling inputs, calculated seasonal demand, scenario results and a concise technical briefing suitable for review by engineers, programme managers or water authorities.

The course is designed for practitioners who already work with agricultural water management data and need a repeatable, auditable method for converting that data into planning outputs.

Course objectives

By the end of this course, participants will be able to:

• Configure a CROPWAT project with climate, rainfall, crop, soil and irrigation inputs for a defined command area
• Calculate reference evapotranspiration using the FAO Penman-Monteith method and interpret monthly climate drivers
• Import and assess CLIMWAT and local weather-station data for completeness, consistency and planning suitability
• Determine crop evapotranspiration using crop coefficients, crop stages and locally adapted planting calendars
• Estimate effective rainfall and distinguish net irrigation requirements from gross scheme water requirements
• Create CROPWAT irrigation schedules using soil-water balance parameters, allowable depletion and irrigation application rules
• Aggregate crop-level schedules into seasonal and peak water-demand estimates for a multi-crop irrigation scheme
• Produce a documented irrigation requirements report with assumptions, scenario comparisons and management recommendations

Benefits of attending

Target competencies

Who should attend

• Irrigation Engineers — who size, rehabilitate or operate irrigation infrastructure and need defensible demand estimates
• Agricultural Water Management Officers — who prepare seasonal irrigation plans for farmer groups or command areas
• Agronomists — who advise on crop calendars, irrigation timing and water-productivity improvements
• Project Engineers and Technical Advisors — who develop agricultural development or resilience project designs
• Water Resources Planners — who assess abstraction demand, allocation needs and competing water uses
• Monitoring, Evaluation and Learning Specialists — who need to verify irrigation-planning assumptions and reported water-demand results

Requirements and prerequisites

Participants should be comfortable working with spreadsheets and interpreting basic agricultural data such as rainfall, temperature, crop planting dates, crop growth stages, soil texture and irrigation method. Prior exposure to irrigation concepts is expected, including the distinction between crop water need, irrigation requirement and application efficiency. Experience with CROPWAT is not required; the course starts with project setup and guided navigation. Participants do not need programming, GIS expertise, advanced hydrology or prior knowledge of the FAO Penman-Monteith equation, although those with field irrigation or design experience will be able to apply the exercises more directly.

Training methodology

The five days alternate short instructor-led technical sessions with guided CROPWAT builds, calculation checks and applied interpretation workshops. Participants work from a shared irrigated-scheme case containing climate records, soil profiles, crop calendars and irrigation-system data, then adapt the model to a scenario relevant to their work. Exercises require participants to inspect assumptions rather than accept default values, compare rainfall and irrigation options, and explain consequences for peak demand. Peer review is used to test technical briefings, followed by an end-of-course action plan for applying the workflow to a live scheme or project.

Course outline

Day 1: CROPWAT foundations and climate data

• CROPWAT 8.0 interface, project structure and calculation workflow
• Irrigation planning outputs for farm, command-area and project-design decisions
• FAO-56 reference evapotranspiration concepts and input variables
• FAO Penman-Monteith ETo calculation within CROPWAT
• CLIMWAT 2.0 station selection and climate-data extraction
• Local weather-station data checks for units, missing values and seasonal plausibility
• Monthly rainfall interpretation and climate-data limitations for planning

Workshop: Participants create a CROPWAT climate file for a selected station, calculate monthly ETo and produce a short data-quality note.

Day 2: Crop and soil water requirement modelling

• Crop calendars, growth stages and planting-date representation
• FAO crop coefficients and dual considerations for local crop conditions
• Crop evapotranspiration calculation using ETo and Kc values
• Soil texture, total available water and maximum rooting depth
• Readily available water and allowable depletion settings
• Effective rainfall methods and selection of planning assumptions
• Net irrigation requirement calculation across crop development stages

Workshop: Participants model two priority crops with contrasting calendars and produce crop water-requirement tables showing ETc, effective rainfall and net irrigation need.

Day 3: Irrigation scheduling in CROPWAT

• CROPWAT irrigation scheduling modes and scheduling assumptions
• Soil-water balance interpretation and depletion thresholds
• Fixed-interval irrigation scheduling for rotational supply systems
• Critical-depletion scheduling for crop-water management decisions
• Irrigation application depth, timing and field-capacity constraints
• Irrigation efficiency, conveyance losses and gross irrigation requirement
• Schedule outputs for seasonal demand and peak-period planning

Workshop: Participants generate and compare fixed-interval and critical-depletion schedules, then recommend one operating schedule for the case scheme.

Day 4: Scheme demand, scenarios and planning decisions

• Cropping-pattern definition and area-weighted demand aggregation
• Staggered planting dates and their effect on peak scheme demand
• Command-area water-demand estimates and monthly demand profiles
• Dry-year and reduced-rainfall scenario testing in CROPWAT
• Irrigation-method efficiency scenarios for surface, sprinkler and drip systems
• Climate-data uncertainty and sensitivity analysis of key assumptions
• Translating CROPWAT outputs into abstraction, storage and delivery decisions

Workshop: Participants build a multi-crop command-area demand scenario and produce a monthly water-demand chart comparing baseline and dry-year conditions.

Day 5: Technical reporting and application planning

• Quality assurance checks for CROPWAT inputs, units and output consistency
• Documenting sources for climate, crop, soil and efficiency assumptions
• Interpreting CROPWAT reports for non-specialist decision-makers
• Presenting net demand, gross demand and peak demand without misrepresentation
• Using AquaCrop outputs and field observations to refine planning assumptions
• Irrigation water-requirements report structure and technical review criteria
• Workplace implementation planning for a live irrigation scheme or project

Workshop: Participants finalise a documented CROPWAT project and deliver a technical briefing with assumptions, demand results, scenario findings and next-step recommendations.

Tools & standards covered

CROPWAT 8.0, CLIMWAT 2.0, FAO Irrigation and Drainage Paper 56, AquaCrop

A typical training day

Live online deliveries follow the same structure in the East Africa Time zone, with shorter screen blocks and longer breaks.

What the fee includes

How you can take this course

Certification

Participants who complete the full five days receive the Skillset Development Certificate of Completion, stating the course title, course code, dates and delivery format — suitable for professional-development records and employer reimbursement.

Frequently asked questions