Scottish Government

4. Existing hydro schemes

Awe Scheme

Ben Cruachan

4.1 The Committee sought clarification from Scottish Power (SP) on a number of issues related to the design and efficiency of new intake screens at Loch Awe.

4.2. The Committee has been aware of and has previously commented upon concerns of the local Fishery Board and Fishery Trust about some aspects of the design of this scheme and its operation. The Committee visited the site in September together with representatives from Assynt Hydro Ltd and Highland Light and Power Ltd.

4.3 The Committee received a copy of a report by consultants to the North and West Sutherland District Salmon Fishery Board regarding upstream access for migratory salmonids at Loch Poll. The local Fishery Board's concerns were summarized in a letter to the Committee in November.

4.4 On the evidence of what it has seen and heard to date it is difficult for the Committee not to conclude that sea trout and salmon were ordinarily present in Loch Poll before the scheme was constructed and, therefore, that the scheme should be subject to the Salmon (Fish Passes and Screens) (Scotland) Regulations 1994. Accordingly, the Committee continues to be concerned about a number of aspects of the scheme particularly the effectiveness of the current arrangements for affording unrestricted access to Loch Poll by migratory fish.

4.5 The Committee is disappointed that it has not yet been possible for Highland Light and Power Ltd to publish the three year Loch Poll Monitoring Programme Report.

Tongland

4.6 The continuing reduction in the adult salmon run of the River Dee (Kirkcudbright) is a matter of considerable concern to the Committee as is the longstanding concern about the effectiveness of the fish pass at Tongland dam.

4.7 Throughout the year the Committee has liaised with the Dee DSFB and in late August two members of the Committee made a further visit to the Tongland site. Particular attention was focused on the performance of changes to the cross-walls of the uppermost chambers of the fish pass and the new upper sluice gate controllers. The members submitted a briefing note as a basis for discussion at future Committee meetings.

4.8 Following a meeting at Kirkcudbright on 10 June 2003, an outline brief for "PIT" tag studies to assess the effectiveness of the fish pass, and other work to study fish movement in the river below the dam was drawn up by FRS for the Dee Board. The proposal was approved by the Board and put to SP for funding. It was anticipated that this plan would be developed to a point where it could be implemented for the 2005 salmon run. The level of funding support offered by SP, while significant, was insufficient to fully fund the whole project without phasing of the work. It is now intended that the "PIT" tagging system, for the fish pass studies will be developed during 2005 for full operation in 2006. The Committee emphasises the importance of all interested parties working closely together to ensure the project is not hindered by further delays.

4.9 In November the Committee received confirmation that SP was proposing to make changes to the compensation regime via the addition of a small turbine set on the existing needle valve outlet. The Committee discussed the proposal in January and wrote to SP requesting further information on a number of issues. In March, SP subsequently confirmed that detailed technical issues are still to be finalized and it is unlikely that any works will begin until 2005/06.

Mucomir

4.11 In March, the Committee sought information from SSE on the survival of smolts as they pass through the turbines. SSE undertook to monitor smolt passage during the 2004 smolt run and report back. The Committee subsequently received written confirmation in September from SSE that no smolts were seen in the area of the generating station during the 2004 run.

4.12 The Committee was advised of reports of large algal blooms in Loch Lochy and the possible impact on generating regimes/fish passage. SSE also expressed concern after algae began blocking both main machine and compensation set intake screens. The Committee sought advice from SEPA who confirmed that they were aware of the problem but could not attribute the phenomenon to a single causal factor.

4.13 In September, the Committee undertook a tour of the main elements of the SSE scheme on the Shin. The Committee inspected the Grudie smolt trap, the screens and Borland fish pass on the diversion dam at Lairg, the Duchally screen intake (upper Cassely), the Dalnessie intake (upper Brora) and Borland fishpass on the main Shin dam. Committee members were particularly interested in the efficiency of screening and fish passage facilities at all sites.

4.14 Committee members have expressed concern about the loss of the annual autumn parr run on the River Grudie into the Shin (due to the removal of screens), and the comparatively small numbers of salmon that ascend the Borland fish passes at the diversion dam and Loch Shin dam on the upper Shin at Lairg.

4.15 The Committee welcomed an announcement by SSE that they would be providing financial support for a research project on the survival of smolts passing through Loch Shin, and the impact of an experimental programme of smolt 'trapping and trucking' measures. The work will be undertaken by the Kyle of Sutherland (KOS) District Salmon Fishery Board and the KOS Fisheries Trust and is scheduled to begin in the Spring of 2005. The Committee looks forward to receiving a report of this record in due course.

Duchally

4.16 The Committee was advised in early 2003 that new screens were to be fitted. In February 2004 SSE gave their reasons for installing a different specification screen to that which the Committee had recommended.

4.17 The new screening facilities were inspected by the Committee in September - as part of their Shin Scheme tour. The Committee will continue to take an interest in the operational efficiency of the new screen.

4.18 In September, the Committee was informed by SSE that it intends to replace the current SSE Mark 10 fish counter with a new Mark 11 fish counter on Duchally Borland Fish pass. This development is part of a rolling programme of replacement of fish counter units at a number of sites around Scotland and is welcomed by the Committee.

Dalnessie intake (Upper River Brora)

4.19 The Committee considered an SSE report on the efficiency of the new intake screen and provided advice in May 2003. Particular attention was focused on the risks of distortion of the screen bars of this new design. The Committee inspected the new screens during its Shin scheme visit in September and will continue to take an interest in their operation and efficiency.

Pitlochry dam tail race

4.20 In early June it came to the attention of the Committee that a number of chains were hanging on the downstream side of the tailrace screens. The Committee raised this issue at a meeting with SSE whereupon they were assured that the chains were new and an important part of screen assembly and that they were unlikely to either cause damage to fish or interfere with fish passage. The Committee will continue to monitor the situation.

4.21 The Committee sought information from SSE on the operation of the Chliostair power station in Harris. The Committee has a particular interest in the lack of screening at the outflow and compensation flow at the site. SSE replied in March to say that the scheme was constructed under the Constructional Scheme No.35 almost fifty years ago, and that the Explanatory Memorandum for the scheme said consideration of electric tailrace screens would be given if it proved necessary after construction. In addition SSE said there is no provision in the scheme for compensation water.

4.22 The Committee sought information from SSE about the results of its trials with a VAKI fish counter on the Morar dam fish pass. The Committee awaits this information.