SCOTTISH Natural Heritage (SNH) is facing a clash with developers over plans to declare dozens of waterfalls off-limits to new schemes to provide hydro-electric power.
The government’s countryside protection agency has identified areas on more than 130 burns in remote ravines along the west coast that it believes are among the richest sites of internationally important mosses and similar plants in Europe.
A rapid expansion of hydro power is being encouraged by the SNP government to help Scotland meet ambitious targets to reduce reliance on fossil fuels such as oil and gas.
But experts at SNH fear that installing hydro schemes at environmentally sensitive locations will reduce the mist and humidity which appear to be vital for the survival of the plants, several of which are extremely rare.
The agency’s research has been disputed by some developers, who said their own studies found evidence that the plants had survived at sites left dry by the country’s original hydro schemes.
The research, carried out jointly with the Plantlife conservation charity and the James Hutton Institute, was presented last week to a conference marking the 70th anniversary of hydro power in Scotland. At the Scottish Renewables conference in Perth, Dr David Genney, the SNH policy and advice officer on bryophytes (mosses and liverworts), said: “Something about these watercourses in ravines is important for these species because they are not found anywhere else. There is something about running water, running down.
“We’re not saying hydro development should not take place there but I think, as an industry and a nation, we should not be looking at them [these sites] for hydro in the first instance.”
Genney said SNH had produced a map of the sites that had been based on assessing 29 nationally and internationally rare species, some of which were on an official conservation danger list.
“They live in the tiny habitat between the watercourse and the forest floor in steep wooded ravines, where the humidity and splash from the water seem to be the key to their survival,” Genney said.
“We would encourage developers to avoid these sites. If they still want to develop a hydro project on one of these sites we would not say they can’t, but they will need to look at it in a lot more detail.”
Davie Black, of Plantlife, said it would “hate to see key zones for mosses and liverworts sterilised by development”.
He said: “We have identified a large section of the west of Scotland as internationally important for these bryophytes, which are much overlooked.
“This oceanic habitat is often dubbed the Celtic rainforest, and for good reason. There are so many different species in such a small area.
“If you start damming rivers and diverting flows you will change the humidity and climate which is so important. We do have this international responsibility for these lush bryophyte communities so we must take extreme caution when doing anything in these areas.”
Hydro developer RWE Npower Renewables said scientists it had commissioned to conduct research had found no proof that hydro schemes harmed bryophytes.
Bill MacGregor, of RWE, said: “They found some of your rarest bryophytes in the zone of old schemes. I suspect that if there was an issue [with hydro schemes having a negative impact on the plants] these would not still exist. They did not find a link between humidity and water flow [and hydro schemes] either.”
Steven Brown, a partner at Harper MacLeod law firm, which specialises in hydro schemes, added: “We have had a hydro scheme knocked back because of the existence of moss on the basis of the precautionary principle.
“If the moss is internationally important, fair enough. But they are not looking at whether this is one out of 100 known sites in the UK.
“If there are 100 sites and yet the government policy is to promote green energy should we not at least have a debate about whether we can sacrifice one of these sites?”
Hydro power currently produces about 12 per cent of Scotland’s electricity.
A report to the Scottish Government in 2010 showed a range of small hydro schemes with a combined potential capacity of 1,204MW – sufficient to supply around a million homes – were viable in rural areas of the country.