Measuring the cost of drought on health: real numbers from Brazil

Drought is a prolonged period of abnormally low rainfall that reduces water availability across a region. It is one of the most economically damaging natural hazards on the planet, affecting an estimated 1.43 billion people globally between 2000 and 2019 [3]. Drought resilience refers to a community's ability to maintain access to water, food, income, and health services during and after a drought. In wealthy regions, resilience is built into the system: piped water, treated supply, and storage buffers absorb the shock. In poorer, more remote areas, those buffers do not exist.

Brazil's semi-arid northeast is one of the regions most affected by severe drought in all of South America. It is home to over 28 million people, is defined by irregular rainfall, high temperatures, and prolonged dry seasons. [2]

Around 38% of the rural population in this region experiences persistent water insecurity. Most communities depend on a combination of rainwater cisterns, small surface reservoirs, and water trucks to meet their daily needs. Beyond a quantity problem, there is also a quality issue: many of these sources are inadequately stored, prone to bacterial contamination, and consumed without being treated. Between 2012 and 2018, the region experienced its most severe meteorological drought — rainfall deficit — on record, pushing these already fragile systems to their limits.

Putting a number on health impacts

A recent study in the state of Ceará modeled the relationship between water access and diarrhea hospitalizations during and after this severe drought. The findings show that reliable water access could have averted thousands of hospitalizations over 2012–2020, with associated economic value equivalent to nearly 9.92% of local GDP in drought-prone municipalities. Scaled to the whole state, avoidable losses reach an estimated USD 1.15 billion [1].

For context, that figure is comparable in scale to the combined drought losses recorded across agriculture, livestock, and industry in the same region during the same period.

What the data looks like on the ground

A complementary study across 3 rural communities in Ceará went deeper, mapping exactly how water source quality connects to disease. The results were direct: communities relying on surface reservoirs and water trucks reported diarrhea rates nearly 4 times higher than those with access to cleaner sources. Water quality testing found E. coli in all reservoir samples, water truck samples, and even several bottled water sources [2].

The study also found a reinforcing economic loop: when primary water sources are depleted, families are forced to purchase water from lower-quality sources. This increased cost adds to the financial burden on households, further limiting access to safer water.

Drought does not just reduce water availability; it also pushes communities toward the least safe options available.

From measurement to action

Understanding the true cost of drought informs where investment in water infrastructure is most needed, where it creates the highest return, and which technologies are worth deploying and scaling.

When health impacts are excluded from economic assessments, the case for investing in water infrastructure is systematically undervalued. The research from Northeast Brazil offers a replicable methodology for closing that gap and a clear signal that the cost of inaction is higher than current models suggest.

The research also explicitly identifies decentralized water generation, including atmospheric water generation systems, as a viable pathway for communities without reliable access to groundwater or piped supply.

This is more than a technical finding to us. At Solaq, we've spoken directly with numerous communities on the ground, and have seen the reality they face firsthand. That's why we're actively working with the 3D4REAL team to bring atmospheric water generation to the people who need water security the most.