Kariba and Volta reservoirs above year-ago levels in October 2026; Laos's Nam Ngum lags

Kariba starts the rainy season with far more water than last year

Hydroweb uses satellite altimetry, which measures water height from orbit, to track lake and reservoir levels. Levels are given in metres (m) above a standard reference surface. Reservoir levels show how much water hydropower dams have available.

• Kariba, on the Zambia–Zimbabwe border, stood at 480.56 m on Oct 22.
• That is down from 482.29 m in early July, as the dry season draws the reservoir down.
• It is about 3.3 m above the 477.16 m of Oct 20, 2025, and roughly 4.5 m above the drought lows of late 2024 (about 476.1 m).
• The region faces a rainy season under threat from El Niño, a Pacific climate pattern.

Ghana's Volta and Brazil's São Francisco reservoirs are also stronger

• Volta, behind Ghana's Akosombo dam, reached 81.18 m on Oct 21. It was at a low of 77.76 m in early July, so the rainy season has refilled it by 3.4 m. The level is already above the 80.76 m recorded in late November 2025.
• Tres Marias in Brazil fell to 568.34 m from 573.40 m in April. It is still about 2 m above the 566.36 m of October 2025.
• Storage at Sobradino in Brazil is +6.28 cubic kilometres (km3) since the satellite record began, against about +1 km3 a year ago.

Laos's Nam Ngum is weaker, and Toktogul has started releasing water

• Nam Ngum in Laos is at 209.89 m. It is refilling from a June low of 199.82 m but is about 2.6 m below the 212.54 m of October 2025.
• Toktogul in Kyrgyzstan held -3.62 km3 compared with its first satellite observation on Oct 22. That is up from -7.87 km3 in March but just below the late-September peak of -3.49 km3, which suggests the winter release has begun. It is a little better than the -4.00 km3 of mid-November 2025.
• The Caspian Sea edged lower to -28.75 m, from about -28.55 m in mid-August. Egypt's Lake Nasser held steady near 178.6 m.