Marine licensing where a site reaches the tideline

If any part of your works falls below mean high water springs, you need a marine licence as well as planning permission. A marine licence for development at the tideline is granted by the Marine Management Organisation under Part 4 of the Marine and Coastal Access Act 2009, and the local planning authority has no power over it. The two consents overlap in a narrow strip of foreshore, and schemes come unstuck when the applicant assumes planning permission settles the question.

The strip matters more than its width suggests. Slipways, outfalls, revetments, piling, scour protection and even the temporary deposit of material during construction can all sit below the line.

Where planning jurisdiction ends

A local planning authority's area extends seaward to the low water mark, so the Town and Country Planning Act 1990 still applies across the intertidal zone. Marine licensing starts higher up, at mean high water springs. Between those two lines both regimes operate, and both consents are needed.

Above mean high water springs, planning permission alone is normally enough. Below mean low water, the marine licence does the work and planning permission is not required, although the authority will often still be consulted. In the overlap, the sequencing question becomes real: which application do you make first, and what does each decision-maker assume about the other.

The answer in practice is to run them in parallel and to make each application acknowledge the other. A planning committee that is told the marine licence is outstanding can still resolve to grant. One that discovers the point from an objector cannot.

Finding the boundary on the ground and on the drawings

Mean high water springs is a tidal datum, not a visible feature, and the mark on an Ordnance Survey plan is a generalisation surveyed at a point in time. On a soft or mobile shoreline it can be some distance from where the water actually reaches.

Three sources are worth having before the drawings are fixed. Admiralty tidal data for the nearest standard or secondary port gives the predicted levels. A topographic survey tied to Ordnance Datum Newlyn lets you plot those levels as contours on the site plan. And the local harbour authority or the Crown Estate will often hold a boundary position of its own, since ownership of most of the foreshore and the seabed rests with the Crown Estate and a lease is needed regardless of consents.

Show the line on the submitted drawings with the datum and the source stated. An application that plots mean high water springs as a dashed line with no explanation invites the Marine Management Organisation to disagree with it.

Activities that need a licence

Section 66 of the 2009 Act describes licensable marine activities, and the list is broader than most people expect. It includes depositing any substance or object in the sea or on or under the sea bed, constructing, altering or improving any works, dredging, and removing substances or objects from the sea bed.

The breadth catches construction method as well as permanent works. Temporary cofferdams, barge moorings, the discharge of concrete washings, and material placed on the foreshore to form a working platform are each capable of being licensable. So is maintenance dredging to keep an existing berth usable, which is a recurring obligation rather than a one-off consent.

Marine works also have their own environmental assessment regime. The Marine Works (Environmental Impact Assessment) Regulations 2007 sit alongside the terrestrial regime, so a scheme can require screening twice, on different criteria, for the same project. Where the terrestrial side is already heading towards an Environmental Impact Assessment, coordinate the two rather than running them as separate workstreams, and remember that an environmental statement must be prepared by competent experts.

Exemptions and the lighter routes

Not every activity below the line needs a full licence. The Marine Licensing (Exempted Activities) Order 2011, as amended, exempts a long list of low-risk activities, usually subject to conditions and often subject to notifying or registering with the Marine Management Organisation first.

Typical exemptions cover small-scale maintenance of existing structures, certain navigational aids, scientific sampling and some emergency works. The organisation operates a self-service route for registering qualifying exempt activities, which is quicker and costs less than a licence application and is the right starting point for minor foreshore work.

Read the conditions attached to each exemption carefully. Most are drafted narrowly, and an activity that exceeds a volume, an area or a timing restriction loses the exemption entirely rather than partially.

Marine plan policies and how they are applied

England's marine plans cover the whole inshore and offshore area, and under section 58 of the 2009 Act public authorities must take authorisation decisions in accordance with the relevant marine plan unless relevant considerations indicate otherwise. The UK Marine Policy Statement sits above them.

In substance the plans work much like a local plan. They allocate priority for certain activities, protect others, and contain policies on coastal change, access, seascape, fisheries, aggregate resources and designated sites. An application that cites the relevant plan policies by number and explains compliance reads considerably better than one that treats the marine side as a technical formality.

Designated sites drive most refusals and most conditions. Marine Special Areas of Conservation and Special Protection Areas require assessment under the Habitats Regulations, and the citation for the site tells you which features matter, in the same way described in our note on Special Protection Area citations and qualifying features. Marine Conservation Zones bring a separate duty. An intertidal Site of Special Scientific Interest often overlaps the works, and reading the notified features in the citation is the quickest way to understand what the objection will be.

The consultee list on a coastal scheme

Coastal applications attract a long consultee list, and the planning officer will not chase all of it for you.

• The Marine Management Organisation on the licence and on any planning application affecting the marine area.
• Natural England on designated sites, protected species and marine conservation.
• The Environment Agency on flood risk, coastal defence and any environmental permit for works affecting a main river or sea defence.
• The Maritime and Coastguard Agency and Trinity House on navigation, lighting and marking.
• The local harbour or port authority, which may also hold its own works licensing powers.
• Historic England on the marine historic environment, including wrecks and submerged landscapes.
• The Crown Estate as landowner of most foreshore and seabed.

A Flood Risk Assessment is almost always needed as well, because a site at the tideline is in Flood Zone 3 and usually within a coastal flood risk area. Climate change allowances for sea level rise and the design life of the structure are the two figures the Agency will test, and both should be taken from the current published allowances rather than from an earlier report.

Sequencing the consents

The practical order of work on a tideline scheme looks like this.

1. Establish ownership and secure agreement in principle with the Crown Estate or other landowner.
2. Survey the site and plot mean high water springs against Ordnance Datum.
3. Work out which elements fall below the line and whether any exemption applies.
4. Pre-application engagement with both the local planning authority and the Marine Management Organisation, separately.
5. Commission the survey work that both regimes need, particularly benthic and intertidal ecology, which has its own seasonal constraints.
6. Submit the planning application and the marine licence application in parallel, each cross-referring to the other.
7. Allow for the organisation's published determination period and consultation stages when programming, and check its current service standards rather than relying on an earlier project.

The honest uncertainty here is timing. Coastal schemes with designated site issues take longer than the service standards suggest, because the assessment work often has to be redone once the regulator has seen the first draft. Build that into the programme rather than discovering it.

This is general guidance rather than legal advice. Check the position with the Marine Management Organisation, your local planning authority or a qualified professional before relying on it.

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