Dudbridge Locks Hydro Scheme - Summary


By Keith Tibbitts

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Dudbridge Locks Hydro Scheme




The Cotswold Canals Trust is working with the Stroud Valleys Canal Company to implement a hydro power scheme at Dudbridge. Both organisations are registered charities.


The Stroud Valleys Canal Company was set up in 2009 to take on the role of maintaining the canal and is effectively the canal landowner.


The Cotswold Canals Trust is the largest canal society in the UK with over 6600 members and the restoration of the Cotswold Canals has massive local support and a support base nationally. The Trust is committed to provide £800k of funding towards the £25m restoration of the Phase 1A length of canal between Stonehouse and Brimscombe. About £640k of this has been raised to date. In addition, Trust volunteers and other waterways enthusiasts are restoring locks and carrying out a great deal of other practical work.


The funding of the proposed hydro scheme needs to be in addition to the £800k already committed as it is not part of the canal restoration as such. The Trust is therefore looking for sponsors and grant providers who may find this type of project particularly attractive.


Aim of the Project


The aim of the project is to derive a long term income to help support the maintenance and operation of restored sections of the Cotswold Canals. Initially this will be the six mile section between Stonehouse and Brimscombe that is currently being restored under the leadership of Stroud District Council. This is due to be complete in about 3 years and is expected to be followed by other lengths and ultimately involve the whole of the canal between Saul on the G&SCanal and Inglesham on the Thames.


In the absence of any likely substantial subsidies from the public sector, it is critical that all opportunities are explored that are capable of helping to sustain the canal into the future for the benefit of the public. We anticipate that the hydro scheme will generate about £21,000 of green energy per year to help sustain the canal into the future.


Technical Outline


The Dudbridge hydro scheme is reasonably straightforward and non-controversial in that it takes the water that currently cascades over two locks and generates power from it. The scheme has been fully discussed with both the EA and Stroud District Council and the necessary approvals should be forthcoming.


The scheme has an intake above the top lock and discharges immediately below the lower one. The fall is about 5m and the flow rates depend on the flows in the canal that derive from the combined flows from Painswick Stream and Slad Brook.


The analysis carried out in the design produced by HydroGeneration has proposed an Ossberger crossflow turbine with a maximum recommended flow rate of 0.700 m3/s but capable of operating efficiently down to 0.117  m3/s. This should generate a maximum of  23kW and 108,196 kWh in an average flow year.


The civil engineering element of the project is made more complex due to the nature of the site and the need for the scheme to be integrated with that necessary to restore the canal. It also means that the civil engineering works have to be undertaken at the same time as the canal works and these are schedule for this summer.


Further detailed information, including drawings, and a site visit is available upon request.




The value of this scheme is in its potential to provide funding towards the future operation and maintenance of the canal. There is little value in building the scheme if most or all of the income is consumed supporting a debt over a long period or is otherwise unavailable to the canal. Therefore whilst we intend to apply for the feed in tariff, the Government's chosen mechanism to subsidise this sort of scheme, we cannot use it as the main means to finance the scheme.


Furthermore, neither the Cotswold Canals Trust nor the Stroud Valleys Canal Company are in a position to take on large debts (always assuming there was someone prepared to lend the money) where there is a risk that future interest rate increases could pose a threat.


The civil engineering work has already been tendered and a budget of £110k has been derived from this.


The remaining works needed to purchase and fully install the rest of the equipment and connect it up are estimated to cost a further £200k making the whole scheme cost £310k.


The aim therefore is to seek sponsorship and grants for the project in the form of capital grants. Due to the need not to lose the opportunity, CCT has agreed that the civil engineering works must go ahead but we are urgently seeking funding to cover the M & E works.


For further information please contact Keith Tibbitts, Dudbridge Locks Hydro Scheme Project Manager tel 01453 860403 mob: 07715 104117





This page was added by Keith Tibbitts on 16/03/2012.

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