Hydrological Recession of the Main Nile in Sudan 2026: Cascading Failures of Water Treatment Intakes and Surge in Waterborne Disease Outbreaks

Abstract

The Main Nile in Sudan experienced an unprecedented recession in June-August 2026, threatening drinking water security for over 10 million people across Khartoum, Gezira, River Nile and Northern States. This study provides the first integrated assessment of the hydrological-infrastructure-health cascade. Daily discharge at El Deim station (Sudan-Ethiopia border) averaged 120 Mm3/d versus historical mean 220 Mm3/d (2000-2020) for July-August - a 45% reduction with no flood pulse, attributed to reduced Blue Nile flows, Grand Ethiopian Renaissance Dam (GERD) filling operations, and a cyclical lean-year period. Water levels fell below critical fixed-intake thresholds, rendering multiple water treatment plants (WTPs) inoperable. Almanara WTP (400,000 m3/d, 1.9M served, Khartoum) suffered 50% production loss requiring emergency dredging and generator-supported pumping, Al-Salihiya (200,000 m3/d) and Berber (50,000 m3/d) failed completely (100% loss), Bahri -30%, Atbara -25%, Dongola -20% due to sandbar intrusion. Low-flow reduced dilution factor Cf=1.8x, increasing pathogen concentration: total coliforms exceeded 20 CFU/100mL (log 6.8) versus WHO guideline 0 CFU/100mL, turbidity high causing chlorination failure. Flood destruction of ∼11,000 latrines amplified cross-contamination. Treatment failures forced direct consumption of untreated Nile water, coinciding with major outbreaks spatially aligned with WTP failures: 24,609 cholera cases (699 deaths) nationally by October 2024, White Nile AWD >800 hospitalizations February 2025 linked to power outage and donkey-cart river collection, Khartoum 2,119 cases/70 deaths in two days May 2025 after 10-day blackout, and intestinal parasites affecting 77.5% of direct Nile users. We propose resilience framework: floating intakes, low-water design at -2.0 m, emergency groundwater wellfield, solar pumping, and binding daily GERD outflow sharing for transboundary early-warning