Hydro
Electricity from dams, reservoirs, and flowing water.
At this rate, one death corresponds to about 94,000–3.8 million people's annual electricity.
Deaths per terawatt-hour
This scale is logarithmic: each step to the right is ten times the previous one, so the visual distance understates how much larger the fossil numbers really are.
counted deaths · modeled deaths
The small grey figure under each source is the same rate turned human: roughly how many people’s yearly electricity corresponds to one death. Coal, about 700–6,000 people; solar, a few million.
The figures as a table
| Source | Low | High | Modeled | 1 death per |
|---|---|---|---|---|
| Hydro | 0.04 | 1.6 | 2% | 94k–3.8M people |
Deaths
0.04–1.6 deaths/TWh
Global figure is dominated by the 1975 Banqiao Dam failure; excluding it gives about 0.04 deaths/TWh.
Our World in Data, What are the safest and cleanest sources of energy?CO₂
1–220 gCO₂eq/kWh
IPCC AR5 WGIII Annex III lifecycle emissions mediansLand
4–200 km²/TWh/yr
UNECE lifecycle assessment of electricity generation optionsCost
no comparable data
Lazard 2026 does not publish a comparable LCOE figure for this top-level source in the site taxonomy.
Lazard LCOE+ 2026, version 19.0The uncounted cost — priced at the central value of a statistical life ($14.1M), Hydro's death toll is worth about $18 per MWh generated. That cost is on no electricity bill. Value of a life →
How it kills
Overwhelmingly through catastrophic dam-failure events, which are rare but can kill on a massive scale. Routine operation is one of the safest sources there is.
What dominates the number
A single event — the 1975 Banqiao Dam failure in China — dominates the global average. Excluding it, hydro sits near 0.04 deaths/TWh, comparable to wind and solar.
What the estimate does not capture
Site conditions, country-specific controls, labor practices, reliability, storage, and long-tail waste questions are outside this coefficient.