Environment Agency Flood Risk Decision Quashed.

Posted: 20th June 2012

An Environment Agency decision that threatened to slash development land values alongside the Manchester Ship Canal has been overturned by a High Court judge.
The Manchester Ship Canal Company Ltd. (MSCCL) went to court after the Agency decided that Victorian sluices that have successfully regulated water levels in the 36-mile-long canal for over a century should be classified as ‘formal flood defences’.
When assessing flood risks in the area, the Agency went on the hypothetical assumption that the sluices would fail and remain closed, although MSCCL argued that the chances of that happening were miniscule.
The result of the Agency's decision was that 300 acres of land owned by Peel Holdings (Land and Property) Ltd, in Salford and Trafford, were classified as having a ‘high probability’ of flooding. That meant the land was far less likely to be viewed as suitable for development.
At a High Court hearing, MSCCL and Peel Holdings pointed to another development close to the canal in Trafford, known as Pomona Island, which had been seen as a potential location for 1,500 new homes until the Agency classified it as being within high risk ‘Flood Zone 3’.
barges on canal
Lawyers for MSCCL and Peel Holdings argued that the Agency's decision to classify the sluices as formal flood defences and to base its flood mapping in the area on the assumption that the sluices would fail and remain closed was ‘irrational’.
Mrs Justice Lang was told that the chances of all four gates in any one sluic e failing to open simultaneously were ‘minute’. If there was such an occurrence, it would be ‘a 1 in 100-year event’.
However, the Agency argued that it had to assess flood risks on the ‘nationally consistent’ assumption that flood defences would fail and that it had followed its guidelines lawfully and rationally.
In her decision, Mrs Justice Lang accepted MSCCL and Peel Holdings' arguments that the sluices had been incorrectly categorised as formal flood defences.
She said: "On the evidence, the sluices are not owned or maintained by MSCCL for the purpose of providing a formal defence against flooding. Their primary purpose is to regulate water levels in the canal, not to limit the spread of flood water over land.
"The Agency failed properly to interpret, apply or have regard to its own policy when it classified the sluices on the canal as formal flood defences, and based its Flood Zone assessment and mapping on the assumption that the sluices would fail and remain closed.
"It was irrational...for the Agency to conclude that the sluices came within the description of 'formal defences'".
The judge accepted the Agency's plea that it was obliged to assess flood risks on the basis that the sluice gates would fail, however remote that possibility might be in the light of the three levels of back-up to ensure they operate correctly.
However, she upheld MSCCL and Peel Holding's judicial review challenge so that the Agency will now have to reconsider its decision.