1. Demands, Supplies & Priorities

2. Demand Sectors Irrigation Livestock Mining Industrial Commercial Ecosystems Domestic Total Water Demand Major Cities

3. Water demand data – Municipal and industrial demand Aggregated by sector (manufacturing, tourism, etc.) Disaggregated by population (e.g., use/capita, use/socioeconomic group) – Agricultural demands Aggregated by area (# hectares, annual water-use/hectare) Disaggregated by crop water requirements – Ecosystem demands (in-stream flow requirements) Demand Data Requirements

4. Agriculture Industry Municipal Cotton Rice Wheat... Electric Power Petroleum Paper... South City West City... Irrigation... Cooling Processing Others Single Family Multi-family... Furrow Sprinkler Drip Standard Efficient... Kitchen Bathing Washer Toilet... SECTOR SUBSECTOR END-USE DEVICE Illustrative Demand Structure

5. Data can be at the level of a site, or disaggregated to any level of detail Entering Demand Data

6. Supply Types Rivers Reservoirs Groundwater –storage capacity –max monthly withdrawal –natural recharge Diversions Other sources (e.g. desalination)

7. User defines supply: – Time series data of riverflows (headflows) cfs, groundwater storage and recharge – River network (connectivity) WEAP simulates supply via simulation of physical hydrology: – Watershed attributes Area, land cover, conductivity… – Climate Precipitation, temperature, windspeed, and relative humidity Supply Data Requirements

8. Reservoir Operations Inactive Zone Buffer Zone Conservation Zone Top of Inactive Top of Buffer Top of Conservation Total Storage Flood Control Zone

9. Linking Supply and Demand Linking supply and demand Return flows to surface or ground water or treatment plants

10. Priority System of Allocation Demand Priorities Supply Preferences = Allocation Order

11. 0 36.5 63.5 6.5 unmet; 8% Same Demand Priorities If there are two demands, both with the same priority and insufficient water to meet their needs fully, WEAP will provide equal % of demand to each. 1 3.5 unmet; 8%

12. 0 40 60 10 unmet Different Demand Priorities If the priorities differ, WEAP will satisfy the first priority fully before giving water to the lower priority.

13. Different Supply Preferences The large demand (70 units) has higher priority for river water, but has a greater preference for groundwater 50 Groundwater 40 20 50 2 1