The development and operationalisation of Peru’s first Drought Management Plan (PGS) demonstrated how science, policy, and multi-sector partnerships can converge to tackle water scarcity. The PGS was not only a technical milestone but also an institutional innovation. It underscored the importance of shifting from crisis response to risk management, ensuring that even in one of the driest corners of the world, societies can secure water for people, productive uses and ecosystems. The initiative was built on years of hydrological research and local experience managing scarce resources, while fostering collaboration between national, regional stakeholders, and international partners.
Background
Peru faces a paradox when it comes to water resources. Although it holds vast freshwater reserves, their spatial distribution is highly uneven. The Pacific basin — home to 18.5 million people (roughly two-thirds of the national population) and a large share of the country’s agricultural and mining activity — holds only 2% of national water resources. This is the case in the southern Tacna Region, located at the fringes of the Atacama Desert, the driest in the world. Annual precipitation rarely exceeds 10 mm along the coast and reaches only 400–900 mm in the high Andean headwaters. Under such constraints, irrigated agriculture — which has been practiced for millennia — and town water supply depend almost entirely on careful management of surface and groundwater, small reservoirs and inter-basin transfers that sustain more than 55,900 ha of cropland and Tacna’s urban population of over 340,000 inhabitants. Even under normal conditions water is scarce, and during droughts, deficits become critical, impacting all productive activities. System regulation alone is insufficient to shield the system from severe drought.
Over nearly three decades, Peru has been engaged in a journey to modernize its water management — from passing the 2009 Water Resources Law to establishing regulatory institutions and basin councils tasked with implementing integrated management on the ground. In Tacna, this process led to the Water Resources Management Plan (PGRH) in 2014 (updated in 2023), which set a long-term vision for the sustainable use of scarce water resources. Yet, the PGRH was inherently strategic, and there remained a pressing need for a short-term, operational instrument that could guide responses during droughts. To bridge this gap local, regional, and national authorities and stakeholders joined forces with the private sector — notably Southern Copper — and an independent scientific partner, Australia’s national agency CSIRO, to design Peru’s first Drought Management Plan (Plan de Gestión de Sequías, PGS). This collaboration brought together political legitimacy, financial commitment, and a transparent science-based framework to address drought in one of the most water-stressed regions of the country.
Through a participatory process that co-designed the plan, stakeholders in Tacna adapted international best practice to the local context, ensuring legitimacy and transparency. This approach sought to answer three fundamental questions:
- When to act?–anticipating drought events before impacts become severe.
- Who is responsible?–clarifying roles for implementation, monitoring, and coordination.
- How to act?–activating a portfolio of mitigation and recovery measures at the right time.
This case study is the story of how those questions were answered in one of the driest corners of the world, and how a collaborative, science-based framework turned them into Peru’s first Drought Management Plan, in operation since May 2023.
Photo by RAMANGASON Landivololona Hanitraharilanto
Actions taken
The development of the PGS in Tacna was grounded in existing institutional experience while introducing a new paradigm for water governance. The initiation of the PGS was guided by clear objectives: to transition from reactive drought response to a proactive, risk-informed management framework, ensuring water security for multiple sectors while addressing social vulnerability. The leadership role was shared between regional and national water authorities, who defined high-level goals, while basin councils, local municipalities, and technical experts contributed to shaping operational objectives. The decision-making process followed a staged approach, starting with an assessment of existing protocols and lessons from the 2015–2016 drought, then moving toward the co-design of new monitoring, modelling, and response measures.
Actions were implemented through a combination of technical and institutional instruments. A newly developed Water Resources Management Model provided a robust, scenario-based understanding of system behaviour under varying drought conditions. Indices and thresholds for drought severity were defined to guide the timing and scope of interventions. Current Contingency Plans, Water Availability Plans, and Distribution Plans were adapted and integrated into the PGS to ensure consistency with existing operational procedures. Stakeholders were engaged through workshops, consultations, and capacity-building sessions, bringing together local and regional authorities, water utilities, irrigation associations, large water users and the private sector (notably mining companies). Each actor’s role was clearly defined for different stages of drought: routine management, early warning (pre-alert), mitigation (alert), crisis response (emergency), and recovery. Coordination mechanisms allowed responsibilities to shift dynamically, maintaining operational continuity while enabling rapid response.
Alternative actions and priorities were evaluated through scenario modelling and participatory workshops. Options considered included different combinations of water allocation restrictions, operational adjustments in reservoirs and distribution networks, and targeted social support measures. Selection criteria incorporated technical feasibility, projected effectiveness in reducing risk, social acceptability, and economic implications. The participatory approach ensured that interventions were co-owned, transparent, and informed by local knowledge. Socio-economic vulnerability assessments helped identify “hotspots” where impacts would be most severe, guiding prioritization and resource allocation.
Through these steps, the PGS was co-developed as an integrated, science-based, and socially responsive framework, balancing efficiency, equity, and resilience. It established a clear operational pathway for decision-makers, providing a tested structure to anticipate, respond to, and recover from drought events in a highly water-stressed region.
The operationalisation of the PGS turned planning into coordinated action. Under emergency, national, regional, and local authorities implemented water use restrictions, prioritising urban supply and ensuring the operation of key hydraulic systems. Existing surface and groundwater reserves were allocated under continuous monitoring and multisectoral coordination. The declaration of emergency enabled institutional and financial mechanisms for rapid response. While the PGS helped prevent urban water shortages, agricultural production—particularly olives—declined sharply, highlighting ongoing challenges in balancing water security, sectoral equity, and economic resilience under extreme scarcity.
Outcomes
The PGS marked a decisive shift from reactive crisis response to proactive risk management. It introduced continuous monitoring of drought hazard through hydrological modelling, the definition of indices and thresholds, and the linking of specific measures to risk levels throughout the year. Elements of the earlier management actions, such as Contingency Plans, were retained and enhanced, drawing on lessons from the severe 2015–2016 drought. The structure of the PGS rested on four pillars: (i) assessment of drought conditions, (ii) definition of indices and thresholds, (iii) a programme of management measures, and (iv) institutional arrangements and monitoring.
The formulation process was explicitly participatory. Through workshops, consultations, and capacity building, local, regional, and national authorities engaged with water users, the private sector, and an independent scientific body. A water resources modelling tool was co-built to provide a transparent framework for exploring scenarios and testing management options. This ensured technical robustness while securing legitimacy among stakeholders. Clear responsibilities were assigned across drought stages, with coordination shifting from basin councils under normal conditions to regional emergency agencies during crises.
Equally important, the plan acknowledged the social and economic dimensions of drought. Vulnerability assessments and socio-economic indicators helped target measures toward the most exposed populations, reinforcing equity and resilience. In this way, the PGS combined prior institutional learning, scientific innovation, and inclusive governance. The result was Peru’s first proactive drought plan, co-designed to balance efficiency, fairness, and sustainability. The next step was to test how this framework could be operationalised in practice, turning principles into concrete action on the ground.
The implementation of the PGS approach translated policy into measurable outcomes on the ground. Despite persistent rainfall deficits and declining storage in major reservoirs, water supply for domestic use was maintained without restriction, underscoring the effectiveness of anticipatory planning and prioritization mechanisms. Adaptive allocation measures were introduced, including a 15% reduction in agricultural water use from key irrigation systems, while contingency sources—such as groundwater and upstream reservoirs—were utilised to bridge critical gaps. These actions reflected an operational shift from reactive crisis response to integrated drought risk management, with institutions acting in concert according to predefined responsibilities and thresholds. Beyond maintaining essential water services, the PGS strengthened the coordination between water authorities, the CRHC, and emergency agencies, ensuring that decisions were grounded in both scientific evidence and institutional legitimacy. Monitoring data and hydrological models provided early signals that guided the activation of contingency measures, reducing delays and uncertainty. The plan also fostered a culture of preparedness and accountability, allowing actors at different governance levels to anticipate stress scenarios and implement proportionate responses.
At the socio-economic level, the PGS helped safeguard vulnerable communities from the most severe impacts, ensuring equity in access while reinforcing resilience in productive sectors. The experience revealed that drought preparedness is not only a technical exercise but also a social process—one that relies on dialogue, trust, and shared responsibility. By bridging science and governance, the plan has become a cornerstone of adaptive water management, offering lessons for scaling proactive drought risk reduction across regions facing similar climatic pressures.
Lessons Learned
Participatory design strengthened legitimacy, yet persistent sectoral conflicts within the CRHC limited consensus. Future plans should institutionalize conflict-resolution, promote inter-sector dialogue, and embed formal mediation mechanisms to align priorities in co-designed frameworks.
Staff turnover and weak institutional commitment undermined continuity and PGS implementation. Structured knowledge transfer, ongoing capacity-building, and formalized mandates are essential to maintain engagement and ensure resilience of operational responsibilities despite personnel changes.
Urban-rural tensions emerged as Tacna’s urban population dominates water demand, challenging equitable allocation. Scenario-based planning, transparent allocation rules, and clearly defined investment priorities can help balance competing needs and support fair, adaptive management during drought events.
The availability of contingency storage in the Tacna reservoirs proved essential, validating the foresight of incorporating such reserves within the Drought Management Plan. This measure enhanced operational flexibility and strengthened water security under prolonged rainfall deficits.
Effective communication emerged as a cornerstone of drought response. Transparent and timely information helped prevent public anxiety and overuse during crises, fostering trust and responsible water use among communities and users.
