Landmark Chambers

Home > Our people > Barristers > Gwion Lewis

Environmental Law

Gwion advises on all aspects of environmental law and he has a diverse range of clients spanning the private, public and third sectors. The 2018 edition of Chambers & Partners UK recommends Gwion as a leading junior in environmental law ("He is a pleasure to work with and immensely collaborative. He creates a team feel”. “He picks up technical details very quickly and thoroughly, and is very good on his feet.”), as does the 2018 edition of Who's Who Legal ("Gwion never fails to impress with his ability to produce high-quality and succinct arguments designed to win in a very short time frame.")

For the last 8 years, Gwion has acted for Natural Resources Wales (and its predecessor, Environment Agency Wales) in all its environmental litigation in the higher courts. He is also frequently instructed by the Environment Agency, Defra, the Welsh Ministers and the Marine Management Organisation in cases raising issues of environmental law.

Gwion’s commercial clients in this area include several large international corporations (Dalkia plc, Covanta Energy, Kent International Gateway) and UK-based companies (Norton Aluminium, Bio E, Wharf Land Investments). He has also been advising many of the UK’s most respected environmental NGOs for several years, including WWF UK, ClientEarth and Friends of the Earth.

Gwion has particular expertise in the following areas:

  • EU environmental law
  • fisheries management
  • flood risk management
  • energy, including hydraulic fracking
  • environmental permitting
  • water resources
  • waste management
  • contaminated land
  • harbour management

Highlights of recent and ongoing work include:

EU environmental law

  • R (Seiont, Gwyrfai and Llyfni Anglers’ Society) v Natural Resources Wales [2016] EWCA Civ 797 – acted successfully for NRW in the first judicial review to raise issues under the Environmental Liability Directive (with David Forsdick QC);
  • Derwent Hydroelectric Power Ltd v Natural Resources Wales (2016) – successfully resisted an appeal against NRW’s decision not to grant licences to abstract and impound water on the River Clywedog due to the appellant’s failure to demonstrate no adverse impact on protected bryophytes;
  • Acting for the Environment Agency in several appeals against its decisions to issue penalty notices under (i) the Greenhouse Gas Emissions Trading Scheme Regulations; and (ii) the CRC Energy Efficiency Scheme Order (ongoing);
  • Advised the Welsh Ministers on the transposition of the Marine Strategy Framework Directive (2015);
  • Advised NRW in relation to the coal-fired operations at Aberthaw power station and their compliance with the Large Combustion Plant Directive (2014).

Fisheries management

  • R (Mott) v Environment Agency [2016] EWCA Civ 564 – resisting a challenge brought on A1P1 ECHR grounds to the Agency’s decisions to set low catch allocations for salmon fishing in the River Wye (with James Maurici QC in the Supreme Court, December 2017);
  • Cook v Environment Agency (ongoing) – acting for the Agency to resist a claim by a fish farm owner who alleges that the Agency has been negligent and/or in breach of statutory duty by not enforcing conditions in a water abstraction licence.

Flood risk management

  • King and others v Environment Agency (High Court, ongoing) – acting for the Agency in several claims seeking A1P1 damages for alleged use of land as a “flood storage” area;
  • Sharp v North Essex Magistrates’ Court [2017] EWCA Civ 1143 – successfully resisted, on behalf of the Environment Agency, a claim challenging its use of land entry powers under the Water Resources Act 1991 to carry out flood defence works rather than using compulsory purchase powers (with Dan Kolinsky QC);


  • Wylfa Newydd nuclear power station, Anglesey (ongoing) – advising Natural Resources Wales on the applications for development consent and various environmental permits;
  • R (Friends of the Earth) v North Yorkshire County Council [2016] EWHC 3303 (Admin) – defending the County Council’s decision to grant planning permission for hydraulic fracking, the first challenge of its kind in the UK (with Sasha White QC);
  • Springs Road, Misson (2016) – advising Nottinghamshire County Council on an application to carry out exploratory drilling for shale gas;
  • Tidal Lagoon Swansea Bay (2015) – acted for NRW throughout the 3-week examination of this application for development consent for the world’s first man-made, energy-generating tidal lagoon;
  • Hinkley Point C, Somerset (2013) – acted for the Marine Management Organisation in the public examination of proposals for a nuclear power station and associated development, with emphasis on marine licensing matters.

Environmental permitting

  • Atlantic Ecopark, Cardiff (2015) – acted for NRW in a 3-day inquiry, resisting an appeal against the Agency’s decision to revoke environmental permits held by the same parent company across several sites.

Water resources

  • River Tywi, Nantgaredig, Carmarthenshire (2017) – acted for NRW in resisting an appeal by Welsh Water against the decision to vary its abstraction licence due to concerns about shad numbers.

Waste management

  • R (Newport City Council) v Welsh Ministers [2009] EWHC 3149 – represented the Welsh Ministers in a challenge to their assessment of landfill allowances for waste disposal authorities in Wales (with Clive Lewis QC).

Contaminated land

  • Advising Basildon Borough Council on contaminated land issues arising from the clearance of the Dale Farm gypsy site (ongoing).

Harbour management

  • Advised the National Accounts Classification Committee on the classification of trust ports (2016);
  • R (Humber Oil Terminals Trustees Ltd) v Marine Management Organisation [2012] EWHC 3058 (QB) – acted for the Marine Management Organisation in its first judicial review, concerned with the ambit of harbour revision orders under the Harbours Act 1964 (with James Maurici).