Water Budget Modeling: WEAP Kaan Tuncok Module 3: Environmental Objectives, Programme of Measures, Economic Analysis, Exemptions Water Budget Modeling: WEAP Kaan Tuncok Afyon, 2015

Outline What is WEAP? Brief overview of WEAP Examples of issues that can be modeled When will the new system be ready? Exercise

Water Evaluation And Planning System Integrated watershed hydrology and water planning www.weap21.org General purpose model building, data management and scenario analysis tools. Integrated analysis across demand and supply. Transparent, flexible and user-friendly with low initial data requirements. Similar user interfaces and terminologies. Widely used in Governments, Universities, Consulting Companies, Utilities and NGOs: 100s of users worldwide. Available at no charge to non-profit, academic and governmental institutions based in developing countries.

Water Evaluation And Planning System Integrated watershed hydrology and water planning model GIS-based, graphical drag & drop interface Physical simulation of water demands and supplies Additional simulation modeling: user-created variables, modeling equations and links to spreadsheets, scripts & other models Scenario management capabilities Groundwater, water quality, reservoir, hydropower and financial modules

WEAP Network Schematic Linking supply and demand Return flows to surface or ground water or treatment plants 5 Main Views

Data for the demand sites is displayed numerically and graphically Data View Data for the demand sites is displayed numerically and graphically .

Read in timeseries data from text files or Access database Reading from Files Read in timeseries data from text files or Access database

Results can be displayed in a number of formats and scales Results View Results can be displayed in a number of formats and scales

Results Displayed on the Map

Favorite charts can be selected to give quick overviews Scenario Explorer Favorite charts can be selected to give quick overviews

Hydropower Specify capacities, efficiencies, and other properties of power generation

Specify variable and fixed costs and revenues Financial Analysis Specify variable and fixed costs and revenues

Specify pollutant loadings Water Quality Specify pollutant loadings

Linking WEAP to MODFLOW

Linking WEAP to MODFLOW

Examples of WEAP Analyses Sectoral demand analyses Land use & climate change impacts on hydrology Water conservation Water rights and allocation priorities Groundwater and streamflow simulations Reservoir operations Hydropower generation Financial analysis Pollution tracking Ecosystem requirements

Linking WEAP to Other Software Customized/Programmed links Groundwater flow and particle tracking models MODFLOW, MODPATH Surface water quality model Qual2K Semi-automated calibration PEST Call WEAP using application programming interface (API) Scenario analysis CARS (RAND Corporation) Model calibration Sensitivity analysis, complex model building Scripts: Visual Basic, Javascript, Python, Perl

WEAP Applications Water Systems Planning Transboundary Water Policy Small Reservoirs Project, Ghana/Brazil California Water Plan, California, USA Guadiana River, Spain Transboundary Water Policy Okavango River, Angola/Namibia/Botswana Lower Rio Grande, USA/Mexico Mekong River, Thailand/Cambodia/Vietnam/Laos Jordan River, Syria/Israel/Jordan Climate Change Studies Sacramento and San Joaquin River Basins, California, USA Massachusetts Water Resources Authority, Massachusetts, USA Yemen Second National Communication Mali Second National Communication Ecological Flows Connecticut Department of Environmental Protection Town of Scituate, Massachusetts, USA Water Utility DSS Application Case studies in Portland, Oregon; Austin, Texas; and Philadelphia, Pennsylvania.

Linking Water Decision Processes Groundwater depletion Water quality Unmet ecological flows Costs Limited sectoral water, increased energy requirements for pumping. Increased energy requirements for desalination. Insufficient water for sectors, even with increased groundwater pumping. Still insufficient water--further enhance supply with desalination. Water demand in each sector Efficiency and Sustainability Water Demand DSS Water Supply Storage Sectoral policies Less water-intensive processes and technologies Water requirements for sectors Water conservation Water requirements Reduced water demands

Exercise

How much river water can a user use? River flow ≠ Water available to a user Also reach gains/losses, reservoir storage, consumptive use, return flows, groundwater, soil moisture, Delivery targets and water allocation priorities Appropriation doctrine (first in time, first in right) By purpose (e.g.: urban demands before environmental) By location (e.g.: upstream, then downstream, or reverse) Prior withdrawals and deliveries Changes from month to month and year to year

Draw a System Schematic Identify major system components and linkages Water sources (surface and groundwater) Demand sites (agricultural, urban, etc..) Source connections to demand sites Outflows from demand sites after use Example 1: A river can supply water to an upstream city and downstream agricultural district. 40% of the city’s withdrawals are collected, treated, returned to the river, and available for downstream use by the agricultural district.

Calculate Allocations Step 1: Draw the schematic Step 2: Determine delivery targets for demand sites (demands) Step 3: Assign priorities to demand sites (delivery preferences) Step 4: Determine water availability Sources Return flows Step 5: Allocate remaining available water to meet delivery target of highest priority demand site Repeat Steps 4 and 5 for next highest priority site.

Calculate Allocations (cont.) Example 2: A river can supply an upstream city and downstream agricultural district. 40% of the city’s withdrawals are collected, treated, discharged, and available for downstream use by the agricultural district. 70 hm3 is available in the river this year. The table shows demand site priorities and delivery targets. What water volume is allocated to each demand site? Demand Site Priority [rank] Delivery Target [hm3/yr] City 2 (lower) 30 Agricultural 1 (high) 60

Calculate Allocations (cont.) Always use mass balance to determine water available to a user (or at model node) Data requirements and allocation calculations get more complex as add demand sites and return flows Hydroinformatics and computer modeling can help!

WEAP Allocation Math In each time step, WEAP solves a small linear program Maximize Demand Satisfaction Meet supply priorities Obey demand site preferences Mass balance Other constraints Embed the LP in a time-series simulation (psuedo code) Such that:

Using WEAP Major Modules Schematic Data Results Scenario Explorer

WEAP Schematic Drag and drop system node components Demand sites Reservoirs, etc. Drag, click, and drop system link components Rivers Transmission links Return flows Add GIS layers to help place components Must include all infrastructure you plan to test in Scenario Explorer

Weaping River Example Schematic

WEAP Data Module Enter data for each schematic component Rivers: Headflows for each month of the simulation Reaches: Reach gains for each month of the simulation Diversions: Minimum flow requirements as reach losses Demand sites: activity levels, use rates, losses, consumption, demand priority (1=highest; 99=lowest) Transmission links: Max flows, supply preference Return flows: routing (percent returned) Reservoirs: storage capacity, initial storage, volume-elevation curve, evaporation, pool definitions, buffer coefficients, priority Enter data or read from input file

Alternatively, right-click any schematic component to also get to the Data module

Tree view, Buttons, and Tabs to navigate to desired data

WEAP Results Module Click the Results icon and recalculate (all scenarios) Choose results from schematic or dropdown lists Numerous options to view, tabulate, and export

Water demands by Demand Site

WEAP Scenario Explorer Define and manage scenarios from Data module Enter input data here too

WEAP Scenario Explorer (cont.) Use Scenario Explorer icon to open scenario dashboard

Conclusions WEAP can simulate priority-based water allocations Drag and drop interface to draw system schematic Entered head flow data for one river View results in numerous formats