Common or Eurasian crane Grus grus, flock flying close to wind turbine, Near Diepholz, Lower Saxony, Germany

Strategic Environmental Assessment

Strategic Environmental Assessment applies to 'plans and programmes' rather than individual projects.

What is Strategic Environmental Assessment?

Strategic Environmental Assessment (SEA) is a similar procedure to Environmental Impact Assessment (EIA) but applies to 'plans and programmes' rather than individual projects.

The European Directive on SEA came into force on 21 July 2004. It applies to a wide range of plans and programmes prepared by statutory agencies, regional planning bodies, local authorities and others.

The directive aims to ensure environmental protection and sustainable development. It requires an assessment of the environmental effects of plans and programmes to be carried out as they are being developed. Public participation is an integral part of the SEA process.

Berney Marshes RSPB Reserve, view across Breydon Water showing wildfowl and windpump, January 2005

Guidance for practitioners

Together with the Countryside Council for Wales, English Nature and the Environment Agency, we have published guidance on Strategic Environmental Assessment and biodiversity.

This helps ensure that biodiversity considerations are appropriately addressed in Strategic Environmental Assessments (SEA).

The guidance explains step-by-step how biodiversity implications can be considered at each stage in SEA.

It examines links between SEA and other procedures such as sustainability appraisal, and provides a ‘toolkit’ of more specific techniques for promoting biodiversity through SEA.

Learning from practice

We have published a booklet of strategic environmental assessment case studies entitled Strategic Environmental Assessment (SEA) – learning from practice.

It shows how UK practitioners are rising to the challenge of carrying out effective SEA for public plans and programmes.

Each case study demonstrates an aspect of SEA or Sustainability Appraisal which has been carried out to a high standard or in an innovative way.


Welsh edition of Strategic Environmental Assessment - Learning from practice. PDF, 912Kb.

Asesiad Amgylcheddol Strategol - dysgu o ymarfer

Major infrastructure plans

In 2009, we commissioned a review of the application of Strategic Environmental Assessment (SEA) to major infrastructure plans in the UK.

The report found significant weaknesses in the way SEA has been used in assessing Scotland’s National Planning Framework (NPF2) and the UK’s National Policy Statements for ports and energy.

To find out more, download the interim and final reports and the report summary, visit our National Policy Statements page.

Strumpshaw Fen RSPB reserve, southern marsh orchid and yellow rattle, in wet meadow

Offshore energy

We have been directly involved in Strategic Environmental Assessments (SEA) for UK offshore energy plans for oil, gas, wind and tidal power through representation on steering groups.

We also respond to consultations on the scope of offshore energy SEAs and on SEA Environmental Reports. Read some of our recent responses from our downloads section.


Offshore oil, gas licensing and wind leasing environmental report consultation (PDF, 257Kb)

UK offshore energy plan SEA environmental report

Department of energy and climate change scoping report consultation (PDF, 208Kb)

Offshore Energy Strategic Environmental Assessment (OESEA2)

Phase one consultation response (PDF, 357Kb)

Severn Estuary Tidal Power Feasibility Study