Media playback is unsupported on your device Media caption The NRW said its fisheries officer has visited the area five or six times over the past year

The main environment body in Wales has been blamed for allowing part of a stream to be destroyed during work to prevent flooding in Conwy county.

The £711,000 project in Llanrwst also took place in the fish spawning season when thousands of eggs are laid.

One senior assembly member called it an "abdication" by Natural Resources Wales (NRW) of its responsibility

NRW said it took a "pragmatic view" in an "exceptional case" where a delay could have threatened the project.

Alun Ffred Jones AM, chair of the assembly's environment committee, said he was concerned.

"It's an indication something went wrong on this occasion," he said. "Habitat restoration in rivers and lakes is their priority and official policy. It seems in this case they disregarded their own policy or because of financial pressure."

He said it seemed a "botched job" and someone should explain and apologise for it.

Former fisheries officer 'shocked and dismayed'

Image caption Stream with flood alleviation work

Image caption 'For fish, this is just like a desert' says Pierino Algieri

Image copyright Pierino Algieri Image caption Algieri said it is 'very important to leave the river bed to be left as it was' so fish can breed

Image copyright Pierino Algieri Image caption As well as trout and elders, eels, otters and kingfishers rely on the stream

The work was carried out last year near the Maes Tawel and Cae Person housing estate.

Pierino Algieri, a former fisheries officer with the NRW, said the gravel bed was removed from the stream where trout used to lay their eggs and it was now "lost forever".

The work also happened during crucial spawning period and had left the former stream "a desert".

"I was absolutely shocked and dismayed," he said.

"I knew there was going to be some concrete or some form or another, I didn't think it would take across the whole of the river bed."

He added: "This was the one of the main most important nursery streams for salmon and sea trout.

"I know the fish are in the main river but they come up these little streams to lay the future off-springs so this is so important, I cannot stress how important they are."

The NRW and council responses:

The NRW said its fisheries officer has visited the area five or six times over the last year.

It said initial advice was not to conduct the work during spawning season, but they were told this would jeopardise the whole scheme.

"We took a pragmatic view that with appropriate mitigation, which we advised needed to be taken by Conwy council, this was acceptable in order to reduce flood risk locally.

"We gave clear and comprehensive advice on what should be done to mitigate for the impact on spawning fish and grounds to enable the stream to recover."

Asked if the advice of the former fisheries officer was ignored or overruled, a spokesman added: "This was an exceptional case as it was made clear to us that a delay to the scheme would affect the availability of funding to Conwy council.

"We did not ignore the advice of our fisheries officer, we used this to advise on mitigation. We are investigating if this advice was followed."

Conwy Council said it consulted NRW "before, during and after construction and all reasonably practicable steps have been taken to minimise the impact on the environment".

It said it would in due course consider re-introducing river gravel.

The Welsh government said it provided more than £604,000 towards the cost in October 2013 with a deadline of March this year for it to be spent.

Conflicted areas?

It is nearly two years since the NRW was formed out of the former Countryside Council for Wales (CCW), Environment Agency Wales and Forestry Commission Wales.

Dr Maggie Hill, former CCW director and worked for nine months at the NRW as head of sustainable communities, said: "Nature, wildlife, landscape and protected areas are the territory where possible conflicts between the environment and economic development play out often and it's where we have tricky decisions.

"My feeling was NRW just didn't really want to be in that territory - they were often embarrassed about having responsibility for wildlife, nature conservation and landscape so on and they didn't really want to take pride in that as a role."

Mr Jones added: "They're a government-sponsored body but they are supposed to be objective in all things. And they're advisers to the government. If they refuse to answer it would seem they're either protecting themselves of someone else. That's not a promising way to start for a young body."