Planning permission has been granted for a micro hydro scheme on the River Don at Kelham Island in Sheffield, despite the fact that it will generate enough electricity to power just 20 homes per year, provided there is enough rainfall and the scheme is managed and operated with maximum efficiency. The scheme in Sheffield is not unique - many thousands of sites across the UK have been identified as 'suitable' for micro hydro development and they are being universally sold as a serious 'green' alternative, a key part of Britain's energy future and a lucrative 'community-based' investment that will help power the nation, paying sustainable dividends to those willing to part with their cash. This blog is a public resource designed to demonstrate the negative ecological impacts of 'low-head' or 'run-of-river' micro hydro schemes and asks why UK taxpayers are funding their development despite the fact that the evidence from the world over is that they do far more environmental damage than good.

Watch the film, 'Kelham Island Hydro', and ask whether what boils down to be a few kettles' worth of hydro-generated electricity is proportionate to the decimation of our little-understood and very fragile river ecosystems.

If you have problems viewing the film from here, please view on Vimeo or watch on Google where you can also download to your pc.


'Kelham Island Hydro'   

Preamble to 'Kelham Island Hydro'

Small scale and micro hydropower generation is a red herring. Investment in non-viable schemes is taking away investment in the development of genuine solutions. Reducing our dependence on fossil fuels is crucial – lets develop and use the things that actually work. Why are we happy to waste our time with anything that does not work? Why are we happy to pay for something that actively does more harm than good?

Hydropower comes in many shapes and forms – but is universally portrayed as perfectly “clean” and “green” energy. Investors are attracted to support these schemes on the understanding that they protect the environment. However, the amount of energy produced by such means is absolutely crucial in determining whether they do more harm than good. 

The greater the energy production – the more chance that a hydropower scheme can be justifiably be thought of as “green”. In other words, you need lots of energy production as credit to pay off your inevitable debt of damage to the planet. This concept is important if you are selling a “green” concept to potential investors and local residents.

Modern manufacture and installation processes are widely known to require a great deal of fossil fuel energy. This fossil fuel usage includes fabrication, transport and installation.  What is less obvious is the range of inevitable and significant impacts on the ecology of the recovering River Don that will result directly from the installation and operation of small and micro-hydropower schemes. The film highlights that the maximum amount of energy that could be produced is far too small to offset this inevitable environmental damage (both direct damage to the river and in terms of its carbon footprint).

The current system of regulation that determines whether such schemes are approved has a number of serious limitations:

·       The schemes that produce the least energy (energy that might offset inevitable environmental damage caused by their installation and operation) are exempt from a formal Environmental Impact Assessment

·       Such Environmental Impact Assessments are only compulsory for schemes with a generation capacity greater than 1 MW (one megawatt – or 1000 kW)

·       Schemes are only currently considered in isolation

·       The combined effect of several schemes  is known to be potentially disastrous – even when the impact of any single scheme could be absorbed by the environment

Sheffield Renewables estimate that electricity equivalent to that used by 20 homes per year will be generated by the Kelham Island scheme. Taking the UK average household electricity usage of 4800 kWh; this equates to a mean generation capacity of just 11 kW:

 20homes x 4800 kWh ÷ 8765.8 hours in a year = 10.95 kW

This is a pitiful capacity. How much energy will have been generated by the time replacement of components and other fossil fuel burning maintenance activities are required? How much of the ecology of the river corridor will suffer in the interim? Watch the film and make up your own mind.

Appendix 1 - Fish Pass This additional chapter to Kelham Island Hydro demonstrates some of the limitations and costs associated with the 'go-to' answer of a fish-pass

Kelham Island Hydro - Appendix 1 - Fish Pass from Waterfeature on Vimeo.


  1. I did not learn anything new, but was interested to see how it is possible to present specific facts in a way that does not provide a balanced view. Examples are:-
    1. You complain about the slow moving water upstream of the weir, but then describe the goit as great habitat specifically because of the slow flow.
    2. The film leads the viewer to believe that hydro schemes will result in many damaging weirs being built, but these weirs have been there for over a hundred years. Hydro schemes offer the ability to improve passage over them. If the scheme only produces 20kW then I calculate that at most 2500l/s would be required to operate it which would result in a very slow water velocity in the goit, not the 'torrent' predicted in your film. I doubt if this increase will change the existing habitat much at at, and could in fact improve it by preventing it silting up again.
    3. The emotive pictures of dead fish are from Holland, presumably because the AT could not find any evidence from the UK. Some figures on the actual likelihood of this happening would be helpful, as just presenting these pictures is a bit like showing a picture of a bloody car crash and suggesting that we all stop driving.
    3.Fish passes can indeed be poorly designed, and the one in your film is clearly not the best. However if built in conjunction with hydro which provides the attraction flow and the incentive to maintain them then they can work very well. If Niagara weir could not be removed then a hydro / fish pass combined scheme would have been very useful here.

    We design and build sustainable low head hydro projects. All of our schemes include full ecological and fisheries surveys, and 4 of the 5 'good' hydro schemes on the AT website are designed by us. We believe that hydro projects actually provide an opportunity to make fisheries improvements that would just not happen without it. I would comment that there is actually a better hydropower resource alongside the weir, which would also have no impact on the depleted reach and provide attraction flow to the fish pass there, so this would be the best place to develop a scheme and what we would have recommended. It seems that in this case the heritage value of the waterwheel has taken precedence.
    Dave Mann, Mannpower Consulting Ltd.

  2. Dear Mr Mann



    Thank you for your comments which are most welcome. In respect of the 'balanced view', you may be unaware of the majority positive press reports that schemes up and down the country, including that at Kelham Island, have been getting. For example, I wonder if you saw the BBC's Countryfile programme in November which reported for a full 8 minutes on the pro's of hydropower with a very glib 20 second section which basically said 'we can just put fish screens in'. This film is attempting to redress a balance which is already heavily overstated in favour of hydropower development.

    Regarding your specific points:

    1) This question has been raised elsewhere too so thank you for giving me opportunity to answer it here. There is a difference between an impounded reach of main river behind a weir (which we have many examples of in industrial rivers) and an off-main-river backwater refuge (which we have very few of). The backwater refuges are vital for many species for juvenile stages as well as being areas that all species of fish migrate into during spate flows to avoid being washed into the sea. The goit race is an 'impounded' stretch of water but its also purely man-made. By contrast, natural river watercourses upstream of an impounding weir are not allowed to run at their natural levels and currents thus affecting many many species but also not attracting the same kinds of habitat that one might expect to find in a mill race. Many tiny hydro schemes will be proposed for mill races too. If they are artefacts of the past which have, over time, actually become beneficial for habitats and they don't substantially affect the main watercourse that they draw from they are worth saving. I'm not certain how much the goit at Kelham Island actually detracts from the main channel but as you can see there's quality habitat below the weir and in the goit itself, and presently only very minimum flows are taken into it through the sluice gate. In any case, the hydro development would significantly impact on both these habitats - the goit habitat is obviously at very high risk, and its alarming to read in the Eco-Assessment (the one written by the same people behind the habitat management plan!) that species would simply move elsewhere, despite the fact there isn't any similar habitat within miles of the site. The goit is developing in a very different way to the impounded main river. It is not subjected to changes in water flow and as a result of this a complex aquatic habitat is developing, with rigid hornwort and Potamogeton water weeds which provide a great habitat for small fish and invertebrates such as dragonflies. These habitats have shown no sign of developing in the impounded river stretches. There is also a valuable sub-marginal habitat including reed mace, water parsnip and water plantain that is also a valuable refuge, and this again has not developed on the impounded stretches. One of the discussions we've had further to the argument in the film about 'notching' the weir in order to reduce the impounding effect upstream of it, is what would happen to the goit if it was then subject to reduced levels. There would certainly be increased vegetation and improved water-flow above the weir but could this be done carefully enough to also preserve the unique goit habitat? Frankly, we don't know yet, but I'd certainly hope so. In any case, that isn't the argument we're in a position to have - right now there is good habitat, which could be better; it will likely be decimated by the introduction of the water wheel.


    PART 2

    2) The film in no way suggests that any new weirs will be built and begins with an overview by an authority on the history of the impoundments. Weirs have been there, in some cases, for almost 900 years; most are much older than the 100 years you state. Most 'run-of'river' hydropower will be installed on redundant weirs. This is also clearly stated in the film. There is an innate presumption in hydropower development that old weirs should be allowed to continue the upstream degraded state of the watercourse – WFD requires that watercourses should not be allowed to deteriorate further; modification/lowering/removal should be the preferred choice of the environmentalist and this is a major point of the film, especially given the negligible returns on energy. What's more, and something that isn't stated in the film, is that some redundant weirs will actually be re-built as is the case on the Yorkshire Calder. Hydropower schemes certainly do offer fish passage opportunities but there is considerable evidence that they are not working in tandem with the turbines and are ineffective. As stated in the film, all flows above absolute base flow will be taken into the goit to power the wheel. The velocity of the flow feeding the wheel will depend to a large degree on the depth and cross-sectional area of the goit. When flow tests were carried out at the proposed site by the developer, a torrent was clearly visible, and it resulted in an 18” Pike being washed into the goit tail. These same tests concluded that the flow wasn't substantial enough and hence the plan to build a second sluice at the head of the goit and remove some of the bank there to accommodate it. Siltation is not a problem so far.
    3) The water-wheel proposals for Kelham Island are based on a German design and the physics of a system do not change simply because we live in a different country. Further, schemes in the UK are being allowed to go ahead with a 'fish-kill' allowance so the pictures are entirely relevant. Who is proposed to count the fish killed and call a halt to the operation once that quota is exceeded? Developers? The film aims to prevent similar incidents in this country – we are not hanging around until the scenario arrives just so that we can photograph it to be able to say in retrospect that we were right to be concerned about fish mortality! This is also the point of the 3mm x 3mm fish screen argument in the film.
    4) (3) Indeed fish passes can work very well but this is clearly not always the case. The 'incentive' to maintain the fish-pass, as you suggest, depends completely on the design of the 'system' as a whole. In the case of Settle Hydro, there is suggestion that there are other factors at play which prevent fish migration – in this case, the sheer vibrations of the turbine itself – indeed the 'fish-friendly' Archimedes Screw - are thought to be preventing salmon from moving upstream (see http://www.yorkshirepost.co.uk/news/at-a-glance/main-section/salmon_fishing_harmed_by_hydro_scheme_1_4193772) and the efficacy of the fish-pass in question remains unknown outside this context. The arrangement at Kelham Island means that it is impossible for the attraction flow to be anywhere other than up the goit channel, directly towards the mechanism.

    I hope to have clarified the points you raise. It would be interesting to know whether you believe the Kelham Island scheme, in its current guise, is a worthwhile venture, both financially, and for the environment.

    Ant Graham

  4. This Hydro Scheme needs to be stopped and stopped now, it will not bring any significant return in the electric supply. Should it supply 20 houses and at the very best output 365 days a year it will earn £12.000 per annum, how much will it cost to build and run, add maintenance to the bill the Good Burghers of Sheffield will be footing a hefty bill for years to come.

    There are enough fools in England full of crackpot ideas and solutions, where it viable it would have been done many years ago messing with nature has a strange habit of coming back to haunt you. Linton and Lynnmouth bear grand witness to that fact. Put the River Don and the Goit back to it's original state, and by the River Don I mean all the way to it's confluence with the Humber from South Sheffield, there are years of abuse still present in many stretches just waiting to get out and bite something or somebody.

  5. Dear Ant

    Many thanks for publishing my comments and for your considered response. I do understand your position and desire to alert people to the potential for problems to arise with hydro schemes, and along with others in the industry, were surprised that the EA issued a licence permitting a limited 'fish kill'.
    It sounds like the depth of water in the goit is very shallow, or the calculations on flow required erroneous as the kind of flow you describe should not be required. On balance I do agree that the current scheme is probably not worthwhile, especially given that the design of the waterwheel proposed does not restore heritage of the site either. As I said above it would have been better to build a larger scheme with an Archimedean screw and modern fish pass at the weir.
    I am pleased that you note that Settle fish pass efficacy remains unknown, as it is not at all clear whether there is actually a real problem here. There are many anecdotal reports and one-sided press articles written on the back of these, but no actual evidence either way. This is a great shame given the controversial nature of the scheme, and of course if there is a real problem then it is of concern and needs to be resolved. We have applied pressure to the EA to investigate and will assist where possible in gathering the evidence required. What is clear however from the fish counter data upstream is that hundreds of fish are still moving upstream, so there is no major issue with migration up the river. What is needed to prove that the screw does not cause any additional delay compared to the fish pass by itself is some detailed site specific monitoring and we would support this in the same way as we have supported other tests with our system. It should also be noted that the existing design of the fish pass at Settle is not ideal and could certainly be improved.
    This year we currently plan to build up to 10 projects with state of the art fish passes alongside screws, and will install counters to monitor the continuous movement of fish upstream for the first time on the River Dart, River Teign and River Camowen. These schemes will provide significant benefits to fish passage, and will also provide valuable data on fish movements in the river, as well as the operation of fish passes alongside screws.