Berliner Wasserbetriebe (BWB) is upgrading treatment for a city that will lose about 7 m³/s of mining-related Spree flow by 2038 at the latest. Until an ozonation stage for trace substances is running at its Schönerlinde plant, BWB is sending more of that plant's treated wastewater into the Panke and Spree, to reduce the load on Tegeler See. The lake matters because about 60% of Berlin's drinking water is bank filtrate, drawn from wells beside the Spree, Havel and Dahme. At the Tegel surface-water plant, BWB also doses powdered activated carbon as needed.
A four-plant programme
Ozonation is planned at Schönerlinde, Münchehofe, Ruhleben and Waßmannsdorf, a programme reported at about EUR 532 million. Schönerlinde's stage is under construction. At Münchehofe, BWB has awarded the planning contract and says the stage will be built by 2032. Its investment page still aims for a fourth treatment stage at all plants by 2027, within EUR 1.5 billion for treatment plants.
Why the lignite exit raises the stakes
Lignite mining in Lausitz adds about 7 m³/s to the Spree, against an average inflow to the Havel at Berlin of 38 m³/s. That flow ends with the phase-out, by 2038 at the latest. Stress tests in the Senate's Masterplan Wasser found river levels could be held with flows cut by up to 75%, but a water-quality problem remained. BWB names treatment upgrades as its most important response.
Pollutants already in the ground
In June 2026, the Senate reported that PFAS limits are exceeded at individual monitoring points in the Johannisthal water protection area. BWB plans to reactivate a waterworks there from 2036, for about 12.8 million m³ a year.
What the full report answers
The report sets out which treatment contracts come next, how BWB's 2027 and 2032 timelines compare, and how the programme is to be financed while charges remain unchanged since 2014.
The full report, Berlin Water Intelligence Report, is available for USD 799 at https://ourfuturewaterintelligence.com/reports/berlin-water-intelligence-report. For a free overview, see https://ourfuturewaterintelligence.com/cities/berlin.