A climate change report by the government body states that the region’s peak river flow is expected to increase by 85 per cent – four times more than anticipated – while surface water is likely to increase 40 per cent by around 2070, which is double the previous forecast.

In light of the increased risk to the flood-prone valley, representatives are calling for the agency to rethink its support of an outline planning application for the business park between Sidford and Sidbury, submitted by Fords of Sidmouth.

But the EA states it has not taken the new figures published earlier this year into account because the site is already allocated in the adopted East Devon Local Plan – a development blueprint to cover the next 15 years.

The EA’s policy states: “The advice will come into immediate effect. However, where local plans or development proposals and associated flood risk assessments are well advanced, the application of the updated allowances could significantly slow down completion or add to costs.”

An EA spokesman said: “We considered the plan and application to be well advanced and therefore reasonable to base advice on the existing allowances.”

The Sid Vale Association (SVA) has threatened legal action if the agency does not review its ‘short-sighted and potentially dangerous’ position on the matter.