On 1 July 2025, HAMBURG WASSER supplied 417,797 m³ of drinking water, its peak day of the year. Its maximum daily supply capacity is 460,000 m³, so that one day used 90.8% of what the waterworks can deliver.
A short heatwave, not a drought
The peak came without a long dry spell. HAMBURG WASSER warns that a dry period like spring 2025, when February brought just 5 mm of rain, could tighten the position if it fell in summer. On an average day in 2025, supply was about 322,000 m³, so the peak ran at roughly 1.3 times normal demand.
A 500,000 m³ target for 2030
The utility's target is 500,000 m³ a day by 2030, an increase of 8.7%. It plans refurbishment at the Stellingen waterworks, an expansion at Curslack and a new build at the Langenhorn site, all at existing waterworks sites. The capacity works sit within EUR 1.15 billion of planned investment for 2025–2029.
Annual margin is thin too
Peak days are one limit; annual volume is another. Abstraction reached 125.3 million m³ in 2025 against a usable groundwater yield of 129.9 million m³, leaving about 4.6 million m³ of headroom. Abstraction rose by 2.2 million m³ in a single year, while water delivered to customers was 1.7 million m³ higher than in 2024. More than 2.4 million people are expected in the supply area by 2050, against about 2.2 million in 2025.
How much of Hamburg's supply depends on the contested Nordheide permit, what the climate data say about recharge and hot days, and which policy changes would widen the margin are examined in the full report. The full report, Water Security and Supply Outlook in Hamburg, is available for USD 249.