Campaigners claim Wiltshire Council failed to carry out legally required checks at the Avon Valley Salmon site, raising fears about potential pollution.
WildFish, a national conservation charity based in Salisbury, said the council did not complete an Environmental Impact Assessment (EIA) ‘screening’ before approving the intensive salmon farm at Downton.
Justin Neal, head of law at WildFish, said: “The council’s failure to conduct an Environmental Impact Assessment is a significant oversight and there is a clear error of law.
WildFish, a national conservation charity based in Salisbury, said the council did not complete an Environmental Impact Assessment (EIA) ‘screening’ before approving the intensive salmon farm at Downton. (Image: Coldwater Salmon Ltd)
“The council did not take into account all of the potential environmental impacts.”
He added that an EIA would have identified risks relating to fish waste, water recirculation failures, and broader environmental harm.
WildFish had previously welcomed the closure of a trout farm on the site but objected to its conversion into a large-scale salmon operation, raising particular concerns about untested water recycling technology.
Despite these warnings, Mr Neal said the council went ahead with planning approval in May.
He said: “While there was an assessment of the risks to the protected features of the Avon – which we think was also defective – the lack of an EIA means that we still don’t know the true extent of several potential negative impacts, including what happens to the fish waste if it is spread on fields or what happens if and when the system fails and the river is polluted.”
WildFish has said it will continue to monitor the situation and may take legal action if it finds evidence of river pollution.
The operator, Avon Valley Salmon, has rejected the claims.
A spokesperson said: “As required by the Environmental Agency (Natural England) we did indeed supply a very detailed environmental report which they analysed for months and finally accepted.”
They added that they have complied with the regulations and use a significant waste water treatment plant which does not discharge into the River Avon.
The planning application concerned a temporary steel and PVC canopy structure of around 3,240 square metres over the existing ponds.
Councillor Mel Jacob, deputy leader of Wiltshire Council, said: “We granted planning permission on 21 May, 2026 for the erection of a temporary steel and PVC canopy structure of approximately 3,240 square metres above existing commercial fishponds. The temporary canopy was not deemed to cause any significant impacts and hence was found to be acceptable and in line with local and national planning policies.
“The decision was taken under officer delegated powers in line with the council’s constitution. Whilst the application received a significant number of comments, this does not in itself result in applications being determined by Committee. Most decisions on planning applications are taken by officers under delegated powers. The decision was therefore taken under officer delegated powers in line with the council’s constitution.
“We are confident in our decision making, and that the correct procedures were followed in respect of the decision that was made to approve the application.”