A group of anglers trying to restore the ecosystem of a river have seen off a challenge by the environment secretary, Steve Reed, who claimed that cleaning up the waterway was administratively unworkable.

Reed pursued an appeal against a group of anglers from North Yorkshire, who had won a legal case arguing that the government and the Environment Agency’s plans to clean up the Upper Costa Beck, a former trout stream devastated by sewage pollution and runoff, were so vague they were ineffectual.

The environment secretary decided, after Labour won the election last year, to continue the challenge, which had begun under the previous Conservative government.