The Hydro-Political Choice: Comparative Water-Constraint Trajectories in Arid and Semi-Arid Systems (2025)

TECHNICAL DATA SHEET — 2025 DATA SHEET The Hydro-Political Choice Comparative Water-Constraint Trajectories in Arid and Semi-Arid Systems AUTEUR Zo Rivomanana Rasoanaivo "Water security in arid and semi-arid systems is not determined by climate alone, but by the type of constraint societies choose to manage over time. Comparative evidence shows that different strategies redistribute vulnerability across physical, energetic, and institutional dimensions." Mars 2025 CITE THIS DOCUMENT (ZENODO DOI) https://doi.org/10.5281/zenodo.18009191 Rasoanaivo, Z. (2025) — The Hydro-Political Choice — DOI: 10.5281/zenodo.18009191 Page 1 / 5 Data Sheet — The Hydro-Political Choice I. Comparative Water-Constraint Trajectories in Arid and Semi-Arid Systems (2025) Executive Summary Scarcity versus Constraint: Evidence from Arid and Semi-Arid Systems Water security in arid and semi-arid systems is not determined by climate alone, but by the type of constraint societies choose to manage over time. Comparative evidence shows that different strategies redistribute vulnerability across physical, energetic, and institutional dimensions. The Saudi Arabian trajectory illustrates the irreversible physical limits associated with largescale groundwater depletion under negligible natural recharge. The Dubai trajectory highlights a structural reliance on desalination, accompanied by long-term dependence on energy supply and global industrial value chains. Israel represents an intermediate pathway, where hydrological constraints are partially redistributed through governance, regulation, reuse, and managed aquifer recharge. For regions such as Androy, available evidence indicates that water insecurity is driven less by absolute hydrological scarcity than by limitations in infrastructure, storage, and governance capacity. Selecting a solution—whether focused on desalination, groundwater management, or hybrid approaches—is therefore not solely a technical decision, but a choice regarding which form of long-term vulnerability is accepted and managed. This document adopts a comparative, system-level perspective based on published data and institutional sources; numerical values are reported as orders of magnitude and should be interpreted as indicative rather than exhaustive or site-specific. 1. Saudi Arabia — The Subsurface Limit (Physical Exhaustion) 1.1. Observed hydrological facts • Groundwater abstraction (historical peak): National abstraction reached approximately 15–20 km³ yr⁻¹ during the 1980s–1990s, driven primarily by irrigated agriculture, equivalent to ~40–55 Mm³ day⁻¹. Despite subsequent policy shifts, agriculture still accounts for ≈65–70 % of national water withdrawals in the early 2020s. Sources: FAO AQUASTAT (2022); US–Saudi Business Council (2022). • Natural recharge: Total renewable groundwater recharge is estimated at ≈4.2 km³ yr⁻¹ nationally. For major fossil aquifers (e.g. Saq–Ram, Wajid), effective recharge is near zero, typically <1 mm yr⁻¹, rendering abstraction effectively non-renewable. Sources: Sultan et al., Frontiers in Earth Science (2022); World Bank (2018). • Piezometric decline: Long-term monitoring indicates localized groundwater-level declines of 30–100 m over three decades in intensively exploited basins (e.g. Al-Qassim, Al-Kharj). Sources: World Bank Water Papers; Ministry of Environment, Water & Agriculture (KSA). Rasoanaivo, Z. (2025) — The Hydro-Political Choice — DOI: 10.5281/zenodo.18009191 Page 2 / 5 • Agricultural contraction: Domestic cereal production subsidies were progressively withdrawn, culminating in the official termination of large-scale wheat cultivation by 2016, to preserve remaining strategic groundwater reserves. Sources: Saudi Vision 2030; FAO Country Reports. 1.2. System-level outcome The dominant constraint was reached in the subsurface, through irreversible depletion of fossil groundwater storage. 2. Israel — The Distributed Limit (Systemic Resilience) 2.1. Observed hydrological and institutional facts • Non-conventional water share: By 2024–2025, approximately 45–55 % of Israel’s total water supply is derived from desalination and reclaimed wastewater. Source: Israel Water Authority (IWA). • Wastewater reuse: ≈85–90 % of treated wastewater is reused, predominantly for agriculture, representing the highest reuse rate globally. Sources: Israel Ministry of Environmental Protection; OECD (2024). • Desalination role: Five large-scale Seawater Reverse Osmosis (SWRO) plants currently provide ≈80–85 % of domestic potable water demand, with additional capacity planned. Sources: World Bank (2023); OECD Water Governance Reviews. • Energy efficiency: State-of-the-art SWRO facilities operate at ≈3.3–3.5 kWh m⁻³, reflecting advanced membrane technology and system optimization. Source: Israel Ministry of Energy. 2.2. System-level outcome Hydrological limits are not eliminated but redistributed across water resources, energy supply, and institutional governance capacity. 3. Dubai (United Arab Emirates) — The Energy–Carbon Limit (Infrastructure Lock-In) 3.1. Observed hydrological and energy facts • Desalination share: More than 90 % of potable water supply relies on desalination. Source: Dubai Electricity and Water Authority (DEWA), Technical Statistics (2024). Rasoanaivo, Z. (2025) — The Hydro-Political Choice — DOI: 10.5281/zenodo.18009191 Page 3 / 5 • Production scale: Peak potable-water production reached approximately 1.5–1.6 Mm³ day⁻¹ in 2024–2025. Source: DEWA Quarterly Operational Reports (2025). • Energy intensity: Average specific energy consumption ranges between 3.5 and 4.5 kWh m⁻³. While unit efficiency improved by >40 % since the mid-2000s, absolute energy demand remains high due to scale. Source: DEWA Sustainability Report. • Carbon footprint: Estimated emissions range from ≈2.5 to 4 kg CO₂ m⁻³, depending on the generation mix. Strategic plans aim to shift fully toward Reverse Osmosis (RO) and integrate solar power under the UAE Net Zero 2050 framework. Sources: Dubai Carbon Abatement Strategy; IEA regional assessments. 3.2. System-level outcome The hydrogeological constraint is bypassed, but the system becomes structurally constrained by energy demand and carbon exposure. 4. Androy Region (Madagascar) — The Governance–Climate Limit 4.1. Observed socio-hydrological facts • Household water cost: During the 2024–2025 drought, prices for a 20-L container reached 5 000–10 000 MGA (≈ 1.05–2.10 USD, using 1 USD = 4 761 MGA on 2 March 2025) in critical districts (e.g. Ambovombe, Tsihombe), representing increases exceeding 500 % relative to normal years. Source: UNICEF Madagascar, Drought Monitoring Bulletin (2025). • Storage sensitivity: Monitoring indicates that while approximately 75 % of sites exhibit normal availability during the rainy season, ≈25 % enter immediate alert status following short rainfall deficits, revealing minimal buffering storage. Source: UNICEF Madagascar WASH Monitoring (2025). • Climatic context: Mean annual rainfall (≈400–600 mm) exceeds that of Riyadh or Dubai, indicating that scarcity is not solely driven by climate but by infrastructure, storage, and governance choices. Sources: Madagascar National Meteorological Service; World Bank Climate Data. 4.2. System-level outcome The binding constraint lies primarily in governance capacity, infrastructure, and climatevariability management, rather than absolute water availability. Rasoanaivo, Z. (2025) — The Hydro-Political Choice — DOI: 10.5281/zenodo.18009191 Page 4 / 5 II. Comparative Insight (Evidence-Based) Across arid and semi-arid systems, water-security outcomes are shaped less by climate alone than by which physical, energetic, or institutional limit is accepted and managed. No trajectory is cost-free; each represents a deliberate redistribution of constraints. 1. Cross-Cutting Technical Considerations (Often Underestimated) 1.1. Water Conveyance and Transport Costs • Water-transport constraint: In Saudi Arabia and the UAE, desalinated water is not only energy-intensive to produce but also to transport. In several systems, potable water is conveyed over hundreds of kilometres and significant elevation gradients (e.g. Ras Al-Khair to Riyadh). Under such conditions, the energy cost of conveyance can approach—or in some cases match—the energy cost of desalination itself, depending on distance, head loss, and pumping efficiency. Sources: World Bank Water Papers; IEA Water–Energy Nexus Reports. • Implication for inland regions: For Androy, this distinction is critical. Producing water at the coast addresses only part of the problem; delivering that water inland introduces an additional, structurally binding energy and infrastructure constraint. Coastal production and inland availability are not equivalent from a systems perspective. 1.2. Operational and Maintenance Lock-In • Beyond energy dependence: The infrastructure lock-in observed in Dubai is not limited to energy. Large-scale desalination systems require continuous access to specialized expertise, imported membranes, chemical reagents, and high-reliability maintenance regimes. • Supply-chain dependence: This creates a structural reliance on global industrial supply chains, exposing water security to disruptions unrelated to hydrology (logistics, geopolitics, market volatility). Operational resilience thus becomes as critical as physical water availability. Sources: OECD Water Governance Reviews; World Bank Desalination Economics (2023). 1.3. The Solar Desalination Paradox The growing emphasis on solar-powered desalination is often presented as a sustainability breakthrough, yet it introduces a distinct set of structural dependencies that are frequently underestimated. Large-scale solar coupling implies reliance on extensive surface areas, photovoltaic panels, energy-storage systems, and grid-balancing infrastructure, all of which are embedded in extractive industrial supply chains with their own environmental footprints. Beyond energy hardware, desalination remains associated with persistent environmental externalities, notably the management of concentrated brine discharges and their impacts on coastal and nearshore ecosystems. End-of-life treatment of membranes, batteries, and photovoltaic components further transfers pressure spatially and temporally. Rasoanaivo, Z. (2025) — The Hydro-Political Choice — DOI: 10.5281/zenodo.18009191 Page 5 / 5 As a result, shifting desalination to solar power redistributes constraints rather than eliminating them, replacing carbon and fuel dependence with long-term material, land-use, and waste-management vulnerabilities that must be governed explicitly. 2. System-Level Interpretation These considerations reinforce a central point of this data sheet: water solutions in arid and semi-arid contexts cannot be evaluated solely on production capacity. Energy, transport, operational complexity, and governance jointly determine long-term viability. 3. The Androy region’s context: Expanding Buffer Capacity In the Androy region, available evidence indicates that water insecurity is not driven by absolute hydrological scarcity, but by a chronic lack of buffering capacity against short rainfall deficits. Mean annual precipitation, while low, is not exceptional by arid-system standards; the binding constraint lies instead in limited storage, fragile distribution infrastructure, and weak institutional mechanisms to absorb climatic variability. From a system perspective, the most effective leverage therefore lies in expanding buffering capacity at the local and intermediate scales, rather than in maximizing production. Interventions that enhance storage, reliability, and continuity of access—whether physical, organizational, or institutional—directly address the dominant constraint. By contrast, large-scale desalination or long-distance transfers primarily displace vulnerability toward energy dependence, logistics, and governance complexity, without resolving the core limitation. In Androy-type systems, water security is less a question of producing additional water than of stabilizing access to existing resources across dry sequences. Making the Constraint Explicit: The Androy case illustrates that water solutions implicitly select the level at which vulnerability is borne. In this context, attempting to bypass governance and storage constraints through technologically intensive supply options risks introducing new dependencies while leaving the original constraint intact. Explicitly recognizing where the system is limited—rather than framing the problem as one of absolute scarcity—constitutes a prerequisite for coherent and durable responses. Author: Zo Rivomanana Rasoanaivo Year: 2025 Document type: Analytical data sheet (comparative, non-prescriptive) Suggested citation: Rasoanaivo, Z. (2025). The Hydro-Political Choice: Comparative Water-Constraint Trajectories in Arid and Semi-Arid Systems. Zenodo. https://doi.org/10.5281/zenodo.18009191 License: Creative Commons Attribution 4.0 International (CC BY 4.0) Disclaimer: This document is intended for analytical and informational purposes only. It does not constitute policy advice, project design guidance, or an endorsement of specific technological options.