Project decision adopted on additional balancing lake
August 14, 2025
The Noorderzijlvest Water Authority can start enlarging the balancing lake De Onlanden in September 2025. On August 14, the Provincial Executive of Drenthe adopted the project decision for the construction of balancing lake additional balancing lake De Onlanden.
Capacity expansion
De Onlanden will soon be able to hold more water. Within the existing quays, the storage capacity will be expanded from 7.5 to 12.7 million cubic meters. This will provide space for an additional 5.2 million cubic meters of water. In the event of extreme rainfall, this water can be temporarily stored (for a number of 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, with full completion following in 2027.
From design to project decision
The draft project decision for the additional balancing lake inspection from December 19, 2024, to January 30, 2025. A total of eighty opinions were received. These opinions were carefully considered by the province when adopting the project decision. Based on the opinions and discussions with local residents, additional measures and customized solutions were included in the final design.
The project decision came into effect on September 17. Appeals against the project decision can be lodged with the Administrative Law Division of the Council of State for a period of six weeks (from August 21 to October 1, 2025).