Roger Brookhouse & Anor v The Environment Agency

Compensation for injury caused by flood-defence works depends on proof of causation, not proof of negligence. Where a claimant alleges that works have damaged an existing building by changing groundwater levels, the tribunal must determine that issue on the factual and scientific evidence. The facts do not speak for themselves where the building is old, pre-existing defects exist and time may itself explain deterioration.

If the works probably raised groundwater levels and that rise probably caused deterioration to the building, statutory causation is established. Future high-tide inflows may reinforce the causal risk where they further raise groundwater levels and introduce saline water.

The claimants owned The King’s Lodging, a historic building beside the River Stour at Sandwich. In 2014 the Environment Agency constructed a sheet-piling flood-defence wall alongside the existing river wall. Following the works, water entered the garden on several occasions and the claimants alleged that groundwater levels had risen, causing damage to the house and threatening further deterioration.

The reference was made under paragraph 5(1) of Schedule 21 to the Water Resources Act 1991. The Tribunal determined causation as a preliminary issue, leaving compensation quantum for later agreement or determination. The central questions were whether the works had raised groundwater levels, whether that change had caused damage to the house, and whether future extra-high tidal inflows would exacerbate the damage.

1. Outcome. The claimants succeeded on the preliminary issue. The Tribunal found that the building had been damaged by the Environment Agency’s works and would be further damaged in the future.
2. Applicable approach. The statutory cause of action did not require proof of negligence. The relevant question was whether the works had caused injury. The Tribunal rejected the submission that the deterioration itself established causation. The building was centuries old, had pre-existing cracks and damp, and had continued to age. Causation therefore had to be determined from the factual and expert evidence.
3. Evidence of damage. The surveyors and structural engineers established deterioration in dampness, cracking and outward movement. They also established that vibrations from construction were insufficient to damage the house. If groundwater levels had risen because of the works, the balance of probabilities showed that the deterioration resulted from the effect of groundwater on the foundations and structure, with further damage likely.
4. Groundwater levels. The hydrological evidence established that groundwater near the house was around 2m AOD in 2018. Evidence from the earlier GL Martin investigation, the swimming pool, local watercourses, expected river levels and the condition of the garden showed that pre-works levels were materially lower, probably nearer 1m to 1.3m AOD. The Tribunal accepted that evidence and found that the works had raised groundwater levels by approximately 0.5m to 1m, probably nearer 1m.
5. Future inflows. Extra-high tidal inflows would recur when river levels exceeded 3.1m AOD. They would introduce saline water and temporarily further raise groundwater levels. They could therefore exacerbate damage caused by the existing rise, with such events likely to become more frequent as sea levels rose.
6. The Tribunal accordingly determined that causation was proved under paragraph 5(1) of Schedule 21 to the Water Resources Act 1991. Quantum remained for later agreement or determination.

Not stated in the judgment. The matter was a notice of reference to the Upper Tribunal (Lands Chamber), which decided causation as a preliminary issue.