Water Scarcity, Climate Change, and Population Movement

A River in Crisis: Why This Matters Now

The Zambezi River sustains over 40 million people across Southern Africa. Yet in 2024–2026, water levels dropped to historic lows. The Kariba Dam, shared by Zambia and Zimbabwe, reached critical thresholds. Hydropower output fell by more than 50% in some periods.

Consequently, entire communities lost electricity, water access, and livelihoods. Rural households that depend on rain-fed agriculture faced repeated crop failure. In Zambia’s Southern Province and Zimbabwe’s Matabeleland South, families began to move—first seasonally, then permanently.

This is not just an environmental crisis. It is a public health emergency and a migration challenge with regional implications, especially for South Africa.

Climate Stress and Water Insecurity in the Zambezi Basin

Climate change has intensified drought cycles across the Zambezi Basin. Rainfall patterns have become erratic. Temperatures have increased steadily since 2000.

According to regional climate data (2020–2025), Zambia and Zimbabwe experienced:

Up to 30% reductions in seasonal rainfall
Increased frequency of El Niño–related droughts
Declining groundwater recharge rates

As a result, water scarcity now affects both rural and peri-urban populations. Smallholder farmers struggle to sustain crops. Meanwhile, urban centers such as Harare and Lusaka face water rationing.

Importantly, water insecurity does not act alone. It intersects with poverty, weak infrastructure, and governance challenges. Therefore, climate stress quickly translates into human mobility.

Migration as a Survival Strategy

When water sources fail, people move. Initially, migration is local. Families relocate to nearby towns or areas with boreholes. However, prolonged drought forces cross-border movement.

South Africa remains a primary destination due to economic opportunities and relatively stronger infrastructure. Evidence from 2020–2025 shows increasing migration flows into cities such as:

Johannesburg
Musina (border town)
Durban

Migrants often cite water scarcity, crop failure, and food insecurity as key drivers. Notably, many do not identify as “climate migrants.” Instead, they describe economic hardship. However, climate stress underpins these conditions.

Public Health Implications in South African Cities

1. Pressure on Urban Health Systems

Migrants frequently settle in informal settlements. These areas already face overcrowding and limited services. Consequently, local clinics experience increased patient loads.

In Johannesburg and Durban, primary healthcare facilities report:

Longer waiting times
Increased demand for maternal and child health services
Rising cases of communicable diseases

2. Water, Sanitation, and Disease Transmission

Water scarcity does not end at the border. Informal settlements often lack reliable water supply. This increases the risk of:

Diarrheal diseases
Cholera outbreaks
Skin infections

During the 2022–2024 cholera outbreaks in Southern Africa, mobility played a role in disease spread. However, poor sanitation infrastructure was the primary driver.

3. Mental Health and Psychosocial Stress

Migration under distress conditions leads to trauma. Many migrants experience:

Loss of livelihoods
Family separation
Xenophobic violence

Healthcare providers in Gauteng and KwaZulu-Natal report increasing cases of anxiety and depression among migrant populations. Yet access to mental health services remains limited.

Policy Landscape: Progress and Gaps

South African Policy Frameworks

South Africa has progressive policies on paper. Key frameworks include:

The National Health Act (2003)
The National Climate Change Adaptation Strategy (2020)
The White Paper on International Migration (2017)

These policies recognize health rights and climate risks. However, implementation gaps persist.

Key Policy Gaps

1. Lack of Climate-Migration Integration
Policies treat climate change and migration separately. As a result, no coordinated response exists for climate-induced displacement.

2. Documentation Barriers
Undocumented migrants face restricted access to services. Although primary healthcare is legally accessible, administrative barriers remain.

3. Weak Cross-Border Coordination
Regional bodies such as SADC lack binding frameworks on climate mobility. Therefore, responses remain fragmented.

4. Urban Planning Constraints
Cities struggle to integrate migrants into service delivery plans. Informal settlements continue to expand without adequate infrastructure.

Case Studies: Lived Realities

Case Study 1: Seasonal Migration from Southern Zambia

A 34-year-old farmer from Southern Province lost three consecutive harvests due to drought. Initially, he moved to Lusaka for casual work. However, water shortages persisted. He later crossed into South Africa via Musina.

Now living in an informal settlement near Johannesburg, he works in construction. However, he lacks documentation. He avoids healthcare facilities due to fear of deportation.

Case Study 2: Women and Water Burden in Zimbabwe

In Matabeleland South, women travel up to 10 km daily to fetch water. One household reported withdrawing children from school to assist with water collection. Eventually, the family relocated to Bulawayo.

Later, two members migrated to Durban. They now work in informal trading. However, they face unstable income and limited access to healthcare.

Case Study 3: Youth Migration and Urban Vulnerability

A 19-year-old from rural Zimbabwe migrated after drought destroyed local livelihoods. He settled in Durban. Without support networks, he experienced homelessness and food insecurity.

Local NGOs eventually connected him to shelter and health services. However, such support remains inconsistent.

Intersectional Vulnerabilities

Not all migrants face the same risks. Vulnerability varies by:

Gender: Women face higher risks of gender-based violence and caregiving burdens
Age: Children experience disrupted education and malnutrition
Documentation status: Undocumented migrants avoid formal services
Nationality and ethnicity: Xenophobia affects access to jobs and housing

Therefore, policy responses must be tailored. One-size-fits-all approaches will fail.

Innovative Solutions and Emerging Practices

1. Community-Based Water Management

In parts of Zimbabwe, NGOs have introduced solar-powered boreholes. These systems improve water access and reduce migration pressure.

2. Mobile Health Services in South Africa

Some municipalities deploy mobile clinics in informal settlements. These clinics improve access for migrant populations. They also reduce pressure on fixed facilities.

3. Cross-Border Health Initiatives

Pilot programs between Zimbabwe and South Africa focus on disease surveillance. These initiatives aim to track outbreaks across borders.

4. Cash Transfer and Livelihood Programs

Evidence shows that cash assistance helps households adapt locally. It reduces forced migration. Programs in Zambia have demonstrated improved food security outcomes.

Policy Recommendations and Implementation Timelines

Short-Term (0–2 Years)

Expand mobile health clinics in high-migration areas (e.g., Musina, Durban)
Remove administrative barriers to primary healthcare access
Strengthen cholera and diarrheal disease surveillance systems

Medium-Term (3–5 Years)

Integrate climate migration into national policy frameworks
Invest in water infrastructure in informal settlements
Develop regional SADC agreements on climate mobility

Long-Term (5–10 Years)

Scale up climate adaptation programs in source countries
Build resilient urban health systems
Establish legal pathways for climate-affected migrants

Research Gaps and Limitations

Despite growing evidence, gaps remain. First, data on climate-induced migration is limited. Many migrants do not report environmental drivers.

Second, health data rarely disaggregates by migration status. This limits targeted interventions.

Third, longitudinal studies on health outcomes are scarce. Therefore, long-term impacts remain unclear.

Conclusion: A Call to Action

The drying of the Zambezi is not a distant threat. It is already reshaping migration patterns and health systems across Southern Africa.

Policymakers must act now. First, integrate climate, migration, and health policies. Second, invest in water and health infrastructure. Third, protect the rights of migrants, regardless of status.

NGOs should expand community-based programs. Researchers must generate better data. Meanwhile, healthcare providers need training and resources to support diverse populations.

Ultimately, climate change will continue to drive movement. The question is not whether people will move—but whether systems are prepared to respond.

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When the Zambezi Runs Dry: Water Scarcity, Climate Change, and Population Movement in Zambia and Zimbabwe