El Niño → southern Africa hydropower monitor

Niño 3.4 anomaly
+1.8°C
week of 2026-07-01
ONI (AMJ)
+0.98
3-month running
Kariba level, 2026-07-06
482.17 m
48.2% usable storage (vs 24.3% a year ago)
Kariba basin rain, 2025/26 season
825 mm
106% of 1981–2020 median
Kariba turbine discharge
988 m³/s
2026-07-05
Zambia refined Cu exports
76.2 kt
May 2026 · K20.2bn earnings
Implied Kariba generation
804 MW
38% of nameplate · ≈7,043 GWh/yr run-rate
How to read this dashboard
  1. Niño 3.4 weekly anomaly — how strong this year's El Niño is running versus previous incidences at the same point in the year. >2°C is considered a super El Niño. Events peak around December; the signal leads southern African rainfall by 3–6 months, making this the earliest indicator in the chain.
  2. Lake Kariba water level — the stock of usable water behind the region's biggest hydro plant, against the levels where rationing historically began (amber) and where generation halts (red). Three independent sources: ZRA gauge, NASA and DAHITI satellite altimetry.
  3. Kariba 2027 outlook — where the lake's next peak (Apr–Sep 2027) lands under each El Niño strength and analogue-rainfall scenario, with the probability it fails to clear the stress bands. The key two-season risk: a weak 2027 peak means entering the 2027/28 drawdown with no buffer.
  4. SEAS5 ensemble — what ECMWF's dynamical forecast model says about Nov–Mar rainfall, versus the statistical ONI relationship. When these two disagree, watch whether successive monthly initialisations converge.
  5. Kariba turbine discharge / implied generation — ZRA's revealed allocation policy. Cuts show up here weeks before load shedding is announced and months before economic data. Implied MW converts water decisions into power terms.
  6. Rainy-season rainfall tracker — from November, the first hard evidence of whether the forecast deficit is materialising, weeks ahead of any river or reservoir response.
  7. Regional water bodies — the spillover map: Cahora Bassa (Mozambique's exports), Lake Malawi (Shire cascade), Barotse floodplain (Kariba inflow lead), Itezhi-Tezhi tailwater (Kafue cascade releases). Z-scores flag departures from seasonal normal.
  8. Copper output — the economic endpoint: Zambian refined-copper exports react to smelter curtailment within weeks; DRC production shows the structural trend (and depends partly on power imported from Zambia).
  9. Data status — pipeline health: every series, its span, and freshness.

Niño 3.4 weekly anomaly — 2026 vs El Niño analogue years

Weeks since 1 Jan of onset year. The southern Africa rainy season at risk is Nov(onset)–Mar(onset+1), weeks ~44–65.

Lake Kariba water level

Operating band 475.5–488.5 m (usable storage 0–100%). Stress bands are empirical, from the 2019–2024 record: 30-day mean turbine discharge below 800 m³/s (heavy rationing, deep load shedding) occurred at levels 475.7–479.5m; deep cuts <500 m³/s clustered at 476–477.4m. Amber = levels where allocation cuts and load shedding historically began.

Kariba 2027 outlook — conditional peak-level projection

Monte Carlo through two fitted relationships: rain = 764 -49·ONI (r=-0.49, ±98mm, n=45); ΔL = 145.8 +0.0143·rain -0.321·L_nov (R²=0.76, ±1.1m, n=33). Reduced form — embeds ZRA's average allocation behaviour over 1992–2026, not reservoir physics. From current level 482.17m, projected season-start (Nov 1) ≈ 480.4m. Bars = 10th–90th percentile of the Apr–Sep 2027 peak; dot = median.

ScenarioSeason rainPeak 2027 (p10–p90)Storage at medianP(peak < 481)P(peak < 478)
ONI +1.0716mm481.9m (479.6–484.3)46%31%2%
ONI +1.5691mm481.6m (479.2–484.0)44%37%3%
ONI +2.0 (central)667mm481.2m (478.8–483.6)41%45%4%
ONI +2.5642mm480.9m (478.5–483.3)38%53%6%
ONI +3.0617mm480.5m (478.1–482.9)36%60%9%
SEAS5 ens. (init Jul 2026, 3/5 mo)753mm482.5m (479.0–485.7)51%28%5%
2023/24 repeat (495mm)—478.8m (477.2–480.3)23%97%26%
1982/83 repeat (672mm)—481.3m (479.8–482.8)42%40%0%
2015/16 repeat (760mm)—482.6m (481.0–484.1)51%10%0%
median season (777mm)—482.8m (481.3–484.3)53%7%0%

SEAS5 seasonal forecast — ensemble view

Each column: one forecast initialisation — box = 25th–75th percentile of the 51-member ensemble's Nov–Mar rainfall (as % of the model's own 1993–2016 climatology for the covered months), whiskers 10th–90th, dots = individual members (latest init only). Solid grey line = normal (100%); dashed red = the observed 2023/24 drought outcome vs CHIRPS climatology. Early inits cover only part of the season; coverage extends monthly through the October init.

Kariba turbine discharge — ZRA's revealed allocation policy

Daily, reconstructed from ZRA pages + Internet Archive snapshots (gaps where no snapshot exists). Cuts here precede load shedding and smelter curtailment. Implied generation (right axis) = discharge × head × 0.90 efficiency, head = level − 390m tailwater — constants validated against rated unit specs (180MW at 227.6 m³/s, 89m head); capped at the 2,130MW nameplate. Head effect: the same discharge yields ~8% less power at 476m than at 484m.

Rainy-season rainfall tracker — CHIRPS basin averages

Cumulative Nov–Mar rainfall over each catchment (ClimateSERV zonal mean of CHIRPS daily; HydroBASINS-derived polygons). Band = 20th–80th percentile of 1981–2020 seasons, dashed = median. The 2026/27 line appears from November — this is the first hard verification of whether the El Niño rainfall deficit is materialising.

Regional water bodies vs seasonal normal

Monthly mean level (solid) against that calendar month's full-history normal ±1σ (band). Chip = latest month's z-score.

Copper output

DRC: monthly mine production from the BCC statistics bulletin (Tableau I.2; ~4–6 month lag; monthly detail verified against annual totals). Zambia: refined copper export volumes from ZamStats posts and Monthly bulletins (~1–2 month lag) — the FX-receipts series, and the one that reacts first to smelter curtailment. Watch Zambia exports against the implied-generation series above during power stress.

Data status

series rows first last
altimetry_dahiti_barotse_floodplain_3241 576 2008-07-27 03:21:38 2026-05-28 17:15:11
altimetry_dahiti_cahora_bassa_209 992 2002-01-19 08:52:23 2026-07-03 20:01:24
altimetry_dahiti_itezhi_tezhi_tailwater_38838 527 2008-08-18 22:31:03 2026-05-31 16:27:33
altimetry_dahiti_kariba_31 2029 1992-11-22 19:58:14 2026-06-09 07:55:27
altimetry_dahiti_malawi_23 983 1992-10-14 16:24:16 2026-05-25 06:01:13
altimetry_dahiti_mweru_217 927 1992-10-21 02:52:57 2026-05-31 16:29:52
altimetry_dahiti_tanganyika_25 817 1992-10-21 02:53:51 2026-05-31 16:30:48
altimetry_gwm_cahora_bassa 754 1992-09-27 00:00:00 2026-06-26 00:00:00
altimetry_gwm_kariba 1017 1992-11-22 00:00:00 2026-07-03 00:00:00
altimetry_gwm_malawi 1220 1992-10-04 00:00:00 2026-07-03 00:00:00
altimetry_gwm_mweru 1199 1992-10-01 00:00:00 2026-06-30 00:00:00
altimetry_gwm_tanganyika 1208 1992-10-01 00:00:00 2026-06-30 00:00:00
copper_drc_production 48 2022-01-01 00:00:00 2025-12-01 00:00:00
copper_zambia_exports 11 2025-07-01 00:00:00 2026-05-01 00:00:00
enso_nino_weekly 2340 1981-09-02 00:00:00 2026-07-01 00:00:00
enso_oni 917 1950-01-01 00:00:00 2026-05-01 00:00:00
kariba_level_zra 28 2025-06-23 00:00:00 2026-07-06 00:00:00
kariba_reservoir_zra 2414 2017-04-01 00:00:00 2026-07-06 00:00:00
rain_kafue_daily 16587 1981-01-01 00:00:00 2026-05-31 00:00:00
rain_kafue_prelim 7 2026-06-01 00:00:00 2026-07-01 00:00:00
rain_kariba_daily 16587 1981-01-01 00:00:00 2026-05-31 00:00:00
rain_kariba_prelim 7 2026-06-01 00:00:00 2026-07-01 00:00:00
seas5_kafue 51 2026-07-01 00:00:00 2026-07-01 00:00:00
seas5_kariba 51 2026-07-01 00:00:00 2026-07-01 00:00:00

Generated 2026-07-08 17:51 · sources: NOAA CPC, Zambezi River Authority (live + Internet Archive), NASA GSFC Global Water Monitor, DAHITI (DGFI-TUM)