In summary proceedings, the Federal Administrative Court ruled in a decision dated 17 February 2026 (Ref.: 9 VR 5.26) that the conversion of grassland may constitute a use of water bodies subject to authorisation. The ruling concerns preparatory measures for the laying of an underground cable. These measures were to include, amongst other things, the ploughing up of grassland. The operator of a waterworks successfully challenged this.
The ruling:
Specifically, the topsoil was to be removed within the working strip, which was 45 metres wide (in the standard profile) and 30 centimetres deep. The court, like the parties to the proceedings, regarded this as a use of water bodies. This is always the case where measures are capable of ‘causing permanent or significant adverse changes to water quality’ (Section 9(2)(2) of the Water Resources Act (WHG)). It is important to note that an adverse change does not have to occur with absolute certainty. The measure need only be fundamentally capable of causing such a change. This was the court’s reasoning in this case. This is because nitrate mobilisation is to be expected as a result of the ploughing. The accumulation of nitrate in groundwater constitutes an adverse change, as the nitrate concentration is subject to monitoring as part of the assessment of the chemical status of groundwater and is subject to compliance with a threshold value of 50 mg/l (see Section 5(1), first sentence, in conjunction with Annex 2 of the GrwV). It was irrelevant to the assessment that part of the affected area was situated within a water protection zone. This is because the reasoning is, in principle, applicable to the entire area covered by the measure. The court was prevented from ruling on areas extending beyond the water protection zone solely for procedural reasons. This is because the waterworks operator has no legitimate interest in the areas outside the water protection zone.
Another key focus of the judgment is the exercise of the authority’s discretion. The court examines in great detail the criteria by which it can be determined whether the authority has carried out the required, open-ended assessment, including the exercise of discretion, and when it has not. The authority attempted to retroactively introduce discretionary considerations by means of an amendment notice; however, the court had previously found a complete failure to exercise discretion in an earlier proceeding. This was unsuccessful, as a complete failure to exercise discretion cannot be remedied retrospectively by mere additions. A new, open-ended review would have been required. However, this is precisely what the authority had failed to do with the amended decision, as the court established through a detailed examination of the structure and wording of the decision.
Implications for practice:
This decision is highly relevant for agricultural businesses. Where grassland is to be ploughed up, the requirements under nature conservation law for authorising the intervention must be observed, as must the conditions for the use of water bodies. Consequently, the lower water authority, which is usually responsible, must be involved in the project. There are primarily two approaches to implementation. Either it can be demonstrated that, due to specific circumstances, the ploughing is already unlikely to cause an adverse change (small area, good natural protection due to the hydrogeological structure of the site), or the expected adverse changes are addressed with appropriate mitigation measures. It is clear from the decision outlined above that the authority originally authorised the ploughing as it accepted a number of mitigating factors, including the time elapsed since the last application of fertiliser.
Please feel free to contact us for further clarification of the decision or regarding your specific project.