Annette Huber-Lee

WEAP21 - A Demand-, Priority-, and Preference-Driven Water Planning Model Part 1: Model Characteristics

Abstract The Water Evaluation and Planning Version 21 (WEAP21) Integrated Water Resource Management (IWRM) model seamlessly integrates water supplies generated through watershed-scale hydrologic processes with a water management model driven by water demands and environmental requirements and is governed by the natural watershed and physical network of reservoirs, canals, and diversions. This version (WEAP21) extends the previous WEAP model by introducing the concept of demand priorities and supply preferences, which are used in a linear programming heuristic to solve the water allocation problem as an alternative to multi-criteria weighting or rule-based logic approaches. WEAP21 introduces a transparent set of model objects and procedures that can be used to analyze a full range of issues faced by water planners through a scenario-based approach. These issues include climate variability and change, watershed condition, anticipated demands, ecosystem needs, the regulatory environment, operational objectives, and available infrastructure.

Relations among storage, yield, and instream flow

[1]xa0An extensive literature documents relations between reservoir storage capacity and water supply yield and the properties of instream flow needed to support downstream aquatic ecosystems. However, the literature that evaluates the impact of reservoir operating rules on instream flow properties is limited to a few site-specific studies, and as a result, few general conclusions can be drawn to date. This study adapts the existing generalized water evaluation and planning model (WEAP) to enable general explorations of relations between reservoir storage, instream flow, and water supply yield for a wide class of reservoirs and operating rules. Generalized relationships among these variables document the types of instream flow policies that when combined with drought management strategies, are likely to provide compromise solutions to the ecological and human negotiations for water for different sized reservoir systems. The concept of a seasonal ecodeficit/ecosurplus is introduced for evaluating the impact of reservoir regulation on ecological flow regimes.

WEAP21 -a demand-, priority-, and preference-driven water planning model Part 2 : Aiding freshwater ecosystem service evaluation

Abstract Potential conflicts arising from competing demands of complex water resource systems require a holistic approach to address the tradeoff landscape inherent in freshwater ecosystem service evaluation. The Water Evaluation and Planning model version 21 (WEAP21) is a comprehensive integrated water resource management (IWRM) model that can aid in the evaluation of ecosystem services by integrating natural watershed processes with socio-economic elements that include the infrastructure and institutions that govern the allocation of available freshwater supplies. The bio-physical and socioeconomic components of Battle Creek and Cow Creek, two tributaries of the Sacramento River of Northern California, USA, were used to illustrate how a new hydrologic sub-module in WEAP21 can be used in conjunction with an imbedded water allocation algorithm to simulate the hydrologic response of the watersheds and aid in evaluating freshwater ecosystem service tradeoffs under alternative scenarios.

Optimal water management and conflict resolution: The Middle East Water Project

[1] In many situations, actual water markets will not allocate water resources optimally, largely because of the perceived social value of water. It is possible, however, to build optimizing models which, taking account of demand as well as supply considerations, can substitute for actual markets. Such models can assist the formation of water policies, taking into account user-supplied values and constraints. They provide powerful tools for the system-wide cost-benefit analysis of infrastructure; this is illustrated by an analysis of the need for desalination in Israel and the cost and benefits of adding a conveyance line. Further, the use of such models can facilitate cooperation in water, yielding gains that can be considerably greater than the value of the disputed water itself. This can turn what appear to be zero-sum games into win-win situations. The Middle East Water Project has built such a model for the Israeli-Jordanian-Palestinian region. We find that the value of the water in dispute in the region is very small and the possible gains from cooperation are relatively large. Analysis of the scarcity value of water is a crucial feature.

WAS-guided cooperation in water: the grand coalition and sub-coalitions.

This paper builds on the earlier development of WAS – a method of dealing with water issues that focuses on water values rather than water quantities and takes into account public values that are not simply private ones (see Fisher et al ., 2005). WAS can be used for infrastructure or policy planning, but it can also assist in the resolution of water disputes. Indeed, WAS-guided cooperation in water can turn what appears to be a zero-sum gain into a win-win situation. It is shown that if WAS sets the rules for cooperation, then, when all claimants use those rules, the coalition of all of them together is stable. Results for possible coalitions of Israel, Jordan, and Palestine are given for varying assumptions as to water ownership. The gains from cooperation are compared and analyzed. WAS-guided cooperation is seen to make the value of ownership shifts relatively trivial.

Using water insecurity to predict domestic water demand in the Palestinian West Bank

Household interviews were conducted in the Palestinian West Bank to examine the relationship between price elasticity, water insecurity and domestic water demand. Water insecurity weights were defined and quantified for each household for use in a multivariate regression model. The model demonstrated that (1) a water insecurity variable improves the ability to estimate price elasticity and that (2) increased water insecurity leads to higher levels of household water demand. The findings suggest that policy-makers can influence domestic water demand by addressing the supply constraints that underlie domestic water insecurity.

Uncertainty in Agricultural Water Demand in the West Bank: Policy Implications for a Developing Economy

Irrigation water use can be significantly affected by crop prices and production costs yet policy makers continue to rely on static analyses that do not properly account for uncertainty in these influences. This is particularly problematic in developing economies which are largely dependent on agriculture but facing severe water constraints. We model irrigation water demand uncertainty in two West Bank agricultural districts by executing a deterministic optimization algorithm (mathematical program) repeatedly using Monte-Carlo simulation. When use is highly constrained as seen in the Jenin district, very different decisions would be made if additional water were available, as illustrated by the water demand curve for the Jericho district. We show how this modeling approach can be used to improve the robustness of policy and infrastructure planning and to explore trade-offs between the resilience and effectiveness of such policies under contrasting demand scenarios. Introduction It has long been recognized that systems analysis techniques used to evaluate water allocation problems are not responsive enough to adequately reflect the true concerns of decision makers (Rogers and Fiering, 1986). One of the primary reasons cited is the insufficient treatment of uncertainty in modeling (Tsur and Dinar, 1997; Harou et al, 2009). As simplifications of reality, significant characteristics of a system are represented as parameters and decision variables and the mathematical relationships among them. Parameters are average or calibrated values that best represent the conditions upon which decisions are made. In truth however, parameter values are not precisely known and small changes can lead to dramatic changes in model outputs (Harou et al, 2009). Water allocation policies and infrastructure must be effective over long planning periods due to their associated expenses and required effort. Robust and resilient planning helps ensure the system performs as intended under a wide range of environmental and economic conditions. Robust interventions are those that can be applied to a set of possible scenarios or outcomes (Watkins and McKinney, 1997).