Board of Directors Meeting - October 21

New measures for clean and healthy water

The water authority has now developed a new package of measures for the 2028–2033 period to further improve water quality. The measures focus on specific improvements to the water system and research into the causes of water quality problems. In turn, this research will lead to proposals for new measures, on which the Board of Directors will take a decision subsequently. 
Among other things, the water authority aims for better identification of sources of pollutants, watercourses where “quality dredging” is necessary by removing contaminated sediment, promoting biodiversity with customised vegetation management, and implementing measures to further improve water quality in streams and other bodies of water. In this way, the package contributes to the goals of the Water Framework Directive as well as to Noorderzijlvest’s ambition for clean and healthy water.

Dredging the Boterdiep between Onderdendam and Bedum

The water authority is preparing to carry out quality dredging in the Boterdiep between Onderdendam and Bedum. We are doing this primarily to improve water quality in accordance with the European Water Framework Directive (WFD). There is a layer of contaminated sediment on the bottom, which causes phosphorus and nitrogen levels in the surface water to remain too high. Removing this bottom layer of sediment will improve water quality over the longer term. This has been demonstrated by previous projects in the Fivelingen area. In addition to improving water quality, the dredging also enhances water flow and navigable depth. The water authority is carrying out part of this project using zero-emission equipment. The contaminated sediment will be transported by water as much as possible to a location where it will be processed. This allows us to minimise road transport. The costs are estimated at €4.5 million. Implementation is scheduled from the third quarter of 2027 to early 2028.

Work on the Onlanden optimisation project Is in full swing

We are also working hard to keep our area safe.
De Onlanden is a balancing lake and a nature reserve. Its storage capacity is being expanded from 7.5 to 12.7 million cubic metres of water. This is being done within the existing flood embankments. In extreme weather conditions, the water level can be raised temporarily. This allows De Onlanden to store more water. 

To make the expansion possible, flood embankments are raised and reinforced, weirs are built, pumping stations are modified, and nature conservation measures are implemented. Approximately 60% of the embankment work has now been completed. Work on the Vischlust Weir and the Doolhof Weir is in its final stages. Work is still in full swing at the Rowolder Weir. Nature conservation measures are also underway at various locations, such as the construction of a channel and several refuge mounds. The work will continue into 2027, at which time various pumping stations customised will also be implemented.

Would you like to follow the meeting?

The meeting is open to the public and can be viewed online. It begins on October 21 at 7:30 p.m. at the Water-authority office, Stedumermaar 1 in Groningen. Noorderzijlvest Agenda - Board Meeting Regular Board Meeting Wednesday, October 21, 2026, 7:30 p.m. – 10:30 p.m. – iBabs Public Portal