Introducing better planning for small-scale hydropower in Wales

12 October 2018

Michael Phillips, Principal Consultant at Dulas, explains how potential changes to permitted development rights will impact small hydro projects across Wales.

The last two decades have seen a sea change in the deployment of new hydropower in Wales, with the number of schemes rising from 45 in 2000 to 175 in 2016, and adding approximately 120MW in new capacity. Total installed hydro capacity now stands at 163MW, generating around 300GWh annually, or 4% of all renewable electricity generation in Wales. While this may seem insignificant in terms of overall contribution, much of this total consists of small-scale hydropower that has been developed by Welsh landowners and communities, who not only benefit from additional income over the lifetimes of projects, but also through construction contracts and other local economic benefits. This is all the more important in rural communities, where income diversification is needed most. Such a model of sustainable development reflects the provisions of the Welsh Government’s Well-Being of Future Generations Act 2015, one of the first and leading legislative provisions worldwide for enshrining sustainability in the economy and wider society.

However, the substantial waning in policy and regulatory support at the UK-wide level over the last decade presents a significant threat to this growth, and there has been a substantial reduction in schemes applying for accreditation under the Feed-in Tariff (FiT). In light of this, devolved governments are exploring new mechanisms to stimulate the sector. The Welsh Government and Natural Resources Wales, supported by the British Hydropower Association, are pursuing several means of further stimulating the small-scale hydro market in Wales. Initiatives range from offering business rate grant relief to developers and communities to the possibility of allowing operational schemes to abstract more water in certain circumstances.

Significantly, and in an ambitious step to reverse the downturn in new hydro schemes coming online, the Welsh Government is seeking to reduce the regulatory burden on some scales of hydro development, and commissioned Dulas to examine the likely impacts of introducing Permitted Development Rights (PDR) for small-scale hydropower. These would allow landowners, communities and developers to introduce new schemes without having to apply for planning permission, thereby paving the way to more relaxed planning controls at a critical time for the renewables sector as the FiT diminishes and the route to market for new hydro capacity becomes more uncertain than ever. This is an ambitious move, but one that those working within the industry in Wales feel may greatly contribute to stimulating the delivery of additional capacity, by removing planning costs from anticipated project expenditures.

Greater flexibility

Dulas’ research focused on the impact of this greater flexibility with regard to planning and water abstraction, while mitigating the impact on the natural environment. This research was published in January 2018 as part of the Welsh Government’s Permitted Development Rights and Small-scale, Low Risk Hydropower report, which forms the basis of the current consultation seeking views on the introduction of such rights that could be realised as soon as later this year. Dulas’ research sought to define and identify those schemes most likely to be of lowest risk to the environment and that would benefit most from reduced planning controls; the research comprised extensive field research, impact analyses and stakeholder consultations with industry figures, local authorities and regulators.

The study established that site characteristics and flow requirements, rather than installed capacity, were the principal determinants of environmental impacts, and that each potential site has its own unique characteristics depending on the available water resource, topography, ecology etc. This presented a real challenge in determining how more relaxed planning requirements could be applied, especially given that the power output of a given scheme, which might more readily lead to a definition of schemes that may benefit from PDR, has only limited relevance to the impact of the development. For example, a 1kW low head scheme that depends on a relatively high flow rate may have a significantly bigger intake structure, and hence potentially pose a greater environmental risk, than a much larger capacity 100kW scheme running off a 200m head with a lesser requirement for construction activity and materials. It was therefore crucial to develop a means of categorising low risk hydro schemes for which more relaxed planning requirements may apply.


The research also collated the views of hydro stakeholders on relaxing planning controls, with responses from some 30 organisations, including seven planning authorities and Natural Resources Wales. Of this total, the vast majority (80%) supported the introduction of PDR for both domestic and non-domestic schemes. A slight majority of planning authorities (four of seven) were not supportive, citing concerns over ecological and flood risk issues, and difficulties in applying such a standard across a diverse range of unique sites. 

Other stakeholders were more supportive of PDR, and several felt that the abstraction licencing system would provide sufficient controls over developments.  Nearly 75% of respondents believed that the introduction of PDR would pave the way to more schemes, despite the recent changes in subsidy support, as planning requirements and disproportionately high planning costs were believed to be primary barriers to the realisation of more small scale schemes. The majority of respondents also concurred that permitted rights should apply to domestic and non-domestic schemes.

The research confirmed a common theme: that it is principally construction practices for new hydro plant that present the greatest threat to the environment, and that improved design and siting of components would lessen impacts. Consultees, such as Natural Resources Wales and local authorities, explained that most environmental incidents during construction resulted from a low level of concern for protecting watercourse and habitats. Dulas consequently formulated recommendations based more upon siting, design and planning aspects, in preference to a more arbitrary size of system. Schemes without required abstraction licences and permits would not qualify, nor schemes located in protected areas such as wetland sites of international importance, protected under the Ramsar Convention, and sites of special scientific interest.

However, locations in National Parks and areas of outstanding natural beauty are not necessarily excluded at this stage from PDR as long as they comply with a number of limitations and conditions. Examples of these include the distance from residential properties of the powerhouse and its permissible footprint (<30m2), preferred intake designs, lengths and widths of pipelines, and the nature of outfalls, among others. Whilst this makes it slightly more challenging to establish whether a given scheme would benefit from PDR, it will incentivise developers and landowners to modify schemes to meet the relevant criteria, thereby reducing environmental impacts, and hopefully encouraging the sector to deliver further schemes.

Despite this, the question naturally remains as to how much the small scale hydro sector will benefit from these changes – particularly given that no generation subsidies are currently planned beyond April 2018 when the FiT concludes. The majority of the developer community, in response to the stakeholder consultation exercise, is firmly of the opinion that avoiding the costs of planning will be an important element in post-subsidy viability. With the Welsh Government’s Energy Generation in Wales (2016) report highlighting the large number of additional sites available for hydropower development, particularly in north Wales, the outcome of the current consultation process will be an important stimulant to new schemes. Equally, and despite the absence of devolved powers over energy regulation, it is clear that the Welsh Government is determined to do everything in its power to sustain and build on the long history and positive contribution of hydro generation in Wales.

In a further recent development, the Welsh Government has instructed Dulas to prepare a Good Practice Guide for small-scale hydropower development that focuses on methods to best control the construction effects of these schemes. The guide includes siting and design advice, best practice construction methods, and information on site reinstatement and restoration practices to ensure the environment at hydro construction sites recovers as fast as possible. The Welsh Government expects to release the Guide as a corollary to permitted development rights, if adopted, later this year. Meanwhile, the Welsh Government consultation on the proposed PDR is currently open and concludes in August 2018. Details are available at



About Dulas

With over 30 years of experience in the renewable energy sector, Dulas is an award-winning renewable energy installer and consultancy, specialising in the wind, solar and hydro sectors.

Since 1982 Dulas has been at the forefront of renewables innovation, helping to plan and install some of the very first UK renewable energy systems. To date, the firm’s engineers, planners and consultants have worked on over 400MW of renewables projects across the UK, offering a complete package of development services to utility, commercial, community and landowner renewable energy schemes. 

Working on thousands of projects internationally, Dulas has provided innovative solutions to energy problems in a range of markets across Africa, Asia and South America.  For more information, please visit:

Intake Pico-hydro scheme intake
Small scale Typical small scale powerhouse
Bar screen intake Bar screen intake
Upstream Upstream scour protection using placed boulders
Michael Phillips Michael Phillips is Principal Conusltant at Dulas.
Powerhouse Stone faced powerhouse with slate roof

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