The referendum on 23 June to decide whether the UK stays in or leaves the EU is generating significant debate. This article looks briefly at some of the possible implications of Brexit for marine and coastal development.

As many commentators are highlighting, the impact on the regulatory landscape of a vote to leave the EU will depend upon the nature of the post-Brexit EU/UK relationship. Existing EU legislation will continue to apply to the UK until the Treaty on the European Union ceases to have effect two years after the UK gives notice of its intention to withdraw, or when any negotiated withdrawal agreement comes into force or any agreed extension period expires. EU treaties and regulations would no longer apply from that point forward. However, EU directives that have been implemented through UK legislation would not automatically cease to apply, because the relevant UK legislation is likely to remain in force (as long as suitable saving provisions are in place when the European Communities Act 1972 (under which most EU Directives are implemented as UK legislation) is repealed).

One of the main pieces of legislation governing development in the marine environment in England and Wales is the Marine and Coastal Access Act 2009 ('MCAA'). Under MCAA, a marine licence is required for 'licensable activities' taking place up to the mean high water spring tide mark (including tidal estuaries, rivers and channels) unless an exemption applies. The scope of activities requiring a marine licence is huge and includes construction, alteration or improvement of any works in or over the sea or on or under the sea bed, and dredging. As MCAA is a piece of UK legislation it would remain in force following an exit from the EU. It may, however, require some amendment if there are changes in environmental legislation following an exit from the EU.

In terms of environmental legislation that applies in the marine environment, if the UK were to leave the EU but remain in the EEA most EU environmental legislation would continue to apply. However the Birds, Habitats and Bathing Water Directives would not. Therefore the UK government could decide to repeal the UK legislation implementing these Directives; for example, the Habitats Regulations and Part I Wildlife Countryside Act 1981.

In addition, most developers will be familiar with the requirements for an Environmental Impact Assessment prior to the grant of development consent for those projects that are likely to have significant environmental effects. The revised Environmental Impact Assessment Directive 2014 has to be implemented through national legislation by 16 May 2017. Therefore even if the UK vote to leave the EU, the revised Directive will need to be implemented during the period until the Treaty on the European Union ceases to have effect two years after the UK gives notice of its intention to withdraw, or when any negotiated withdrawal agreement comes into force or any agreed extension period expires. Following that withdrawal it would be up to each of the devolved administrations in the UK to decide how much of the EIA process to retain.

Marine European protected sites (SACs and SPAs) (within which development may be restricted) are not underpinned by national legislation. However, the UK could decide to re-designate all of the existing sites as Marine Conservation Zones (at least as an interim measure).

It is unclear at this stage whether the UK would amend existing environmental legislation or implement new legislation to afford a similar level of protection to that afforded by the EU Directives described above. However it seems unlikely that the UK would significantly lower the current environmental standards.

As described above, the impact of the vote to Brexit on marine and coastal development is unclear. However, those considering embarking on such developments at this time of uncertainty should continue to ensure that their environmental reports and surveys meet the requirements of all existing EU Environmental Legislation (including that likely to be in force by the time their applications for development consent are submitted in the next couple of years).