Fish Pass Clearance

SPRITE have posted a video of their massive efforts to clean up the fish pass on the River Don at Niagara Weir following a double spate.

'Only a few weeks after an exhausting effort to clear flood debris from the fish pass at Niagara weir on the River Don, another spate set things back to square one in July 2012. The local volunteers of the community group SPRITE set to work again and, along with their multiple additional works, become part of a long legacy of groups and heroic individuals from Yorkshire who have helped this post industrial river onto a fragile recovery path. It is significant that these works are going on at a time of great political pressure for widespread adoption of low-energy producing and ecologically damaging micro- hydropower schemes. These give a financial imperative to retain the impounding barriers in their entirety and also limit the efficacy of fish passes.'

Fish Pass Clearance by SPRITE from Paul Gaskell on Vimeo.

Screening and Cleaning

One of the issues raised in Kelham Island Hydro is the importance of adequate screening to prevent juvenile fish from entering the turbine channel from both up and downstream positions. The ideal size is just 3mm x 3mm. To give an idea of how difficult maintenance of such a screen can be, take a look at the before and after pictures below which show the accumulated debris caused by recent flooding at Niagara weir. The 'trash-screen' is at the upstream entrance to the fish-pass.

Before

After

The screen in this case is intended to allow passage of fish and is therefore deliberately large, but if you imagine the amount of debris that will frequently accumulate on much smaller screens intended to stop fish passage, i.e. those that need to be installed on a hydro-power channel, then you can also imagine the levels of maintenance that will be required to ensure that adequate levels of water flow through and keep the turbine running at an optimum. Cost effective? No maintenance costs were factored into the published feasibility survey for Kelham Island.

The maintenance of Niagara fish-pass is undertaken by volunteers working for SPRITE and I'm hugely indebted to that organisation for providing these illuminating images. Keep up the brilliant work!

Protecting Freshwater Diversity - A Promo!

Interesting new short video emphasising just how important colonies of freshwater invertebrates are to the planet, how impoundments - e.g. weirs - affect them, and highlighting the fact that they form the most overlooked and least understood component of many of the aquatic ecosystems we think we already know. Its from the States so they've gone for cheesey blockbuster production, but the message is, nonetheless, clear:


(Thanks to PG)

Some very overdue updates, regarding invertebrates and their habitats closer to home, are coming soon!

Settle Hydro - EA evidence that fishery is affected

The EA investigations into complaints about the Settle hydro scheme have begun. The basis of the complaints are that the scheme is affecting fish migration, in particular Salmon, which are prevalent in the River Ribble on which the hydro station stands. From the Yorkshire Post article: Brian Shields, senior fisheries specialist for the Environment Agency, said: “ We believe there is sufficient evidence that fisheries have been affected for some form of action to be taken. “There is a whole range of options and in discussion with the operators we will have to find something that is workable and legally enforceable.” It seems the scheme isn't exactly living up to its 'environmental' plaudits after all and all for the sake of just 50 homes worth of electricity per year.

River Itchen Hydro Abandoned

Excellent work by the Salmon and Trout Association (SATA), working together with local fishery interests, has led to the withdrawal of a planning application by Eastleigh Borough Council to develop a 'run-of-river' or 'low-head' micro-hydro scheme on the River Itchen in Hampshire. It seems that the winning thrust of SATA's objections, led by leading environmental solicitor Guy Linley-Adams, was focussed around the scheme's incompatibility with the EU Habitat Directive. The River Itchen, a chalkstream, is designated a Special Area of Conservation (SAC) due to its Atlantic Salmon populations which use the river as a spawning ground, and in which juvenile fish develop before they embark upon their incredible journey into our oceans. The Itchen is also one of the most prestigious pleasure-fisheries in the UK, attracting fly-fishers from across the globe, and, consequently, it holds significant economic value to the county.

SATA CEO, Paul Knight, highlighted the impact the intended scheme would have on the hydrology of the river by 'slowing and deepening the water' above the proposed micro-hydro site. Locally, in Sheffield, this point has real synergy with the proposed development at Kelham Island and its an argument clearly illustrated by Dr Paul Gaskell in 'Kelham Island Hydro' when he discusses the ecological impacts of the perpetuation of the Kelham Island weir. As viewers will know, the channel upstream of any weir is 'impounded', which is bad news for the bio-diversity of hundreds of metres of river habitat. By and large run-of-river micro-hydro schemes need to preserve, or, even worse, resurrect, similar impoundments in order to generate power.

Sheffield's River Don, and rivers like it across the UK, do not have SAC status, despite the fact that Atlantic Salmon historically spawned at their headwaters and the fact that, year upon year, these remarkable fish continue their attempts to repopulate. These efforts have been devastated over centuries by man-made obstacles and pollution. As Chris Firth says in 'Kelham Island Hydro', 'those structures still impede the free movement of fish'. In Sheffield, the river's ecosystems are recovering after centuries of industrial degradation, and voluntary organisations like SPRITE and the Don Catchment Rivers Trust have been instrumental in cleaning up the waterway and improving its habitats, giving a significant helping hand to the re-establishment of natural wildlife orders; Sheffield is not alone in its incredible efforts - see, for example, the work of The Wandle Trust, a group who have, against inconceivable odds, revived the London River Wandle from its official classification as 'an open sewer' to the vibrant inner-city watercourse it is today.

But we cannot hope to attract the talents of a Guy Linley-Adams or to access fully any other resource of a major pressure group such as SATA to examine, campaign against, or object to every local proposal because groups such as SATA have finite resources which are spread over many other serious issues affecting their cause, and they prioritise duly. Instead our objections are local and voluntary and we must hope that the decision-makers, especially those within local authorities across Britain, will truly understand the basic tenets of a sound environmental argument and that they will acknowledge the example set by SATA in the case of the River Itchen and consider the evidence of the negative ecological impacts that are beginning to emerge from that flagship of micro-hydro tinkering on the River Ribble, Settle Hydro.

David Browse, Secretary of the Hampshire Salmon Trust said of the Itchen proposal, 'This hydropower scheme would have provided minimal energy generation compared to the potential impact on salmon and other aquatic species, and we felt we were being let down by the very people who should have been responsible for their protection.' Sound familiar? The full SATA article is here.

River Lamprey Radio

Fascinating BBC Nature documentary about these ancient little critters and the significance of conservation measures being taken. Unsurprisingly such measures include tackling barriers such as weirs in an effort to allow lampreys to migrate and spawn. Specific 'Lamprey passes' are being pioneered with some success but barriers coupled with persistently low river flows mean that life for the lamprey is still far from easy.

Where's Whalley?

A micro-hydropower scheme proposed for the Lancashire Calder at Whalley looks set to be rejected planning permission, despite having received a 'feasibility-survey' grant of £20k from the UK government. It would seem that anglers and others were instrumental in the successful objections, based on 'the impact of the scheme on the river environment and fish stock levels, noise from the generator and the risk of flooding', but in actuality the overarching swing-factor for the local Councillor was that the scheme would have a harmful 'visual impact'!

Full article here .

Thanks to JayZS