Project decision adopted on expanded balancing lake
August 14, 2025
Noorderzijlvest Water Authority begin expanding the balancing lake De Onlanden in September 2025. On August 14, Provincial Executive the Province of Drenthe approved the project decision for the realisation balancing lake additional balancing lake De Onlanden.
Capacity expansion
De Onlanden will soon be able to hold more water. Within the existing flood embankments , the storage capacity flood embankments expanded from 7.5 to 12.7 million cubic metre. This provides space for an additional 5.2 million cubic meters of water. During extreme rainfall, this water can be temporarily stored (for a few days) before being discharged into the sea. The water level may rise to +18 cm NAP. The additional balancing lake is expected to be partially operational balancing lake 2026; full completion is scheduled for 2027.
From design to project decision
The draft project decision for the additional balancing lake was available for public consultation from 19 December 2024 to 30 January 2025. A total of eighty consultation responses were received. These consultation responses were considered carefully by the provincial executive when it adopted the project decision. Based on the consultation responses and discussions with local residents, additional measures and customised solutions were included in the final design.
The project decision came into effect on 17 September. Appeals against the project decision can be filed with the Administrative Law Division of the Council of State for a period of six weeks (from 21 August to 1 October 2025).