Planning permission for a slipway or jetty on a tidal river

Jetty planning permission river questions almost always have the same shape: someone owns the bank, wants a structure to reach the water, and discovers that planning permission is one of four or five consents rather than the whole job. On a tidal river you are normally looking at planning permission from the council, a marine licence, a flood risk activity permit from the environmental regulator, consent from the navigation or harbour authority, and a lease or licence for the bed and foreshore from whoever owns it.

They run on different timescales and none of them is conditional on the others in a helpful order. Sequencing is most of the skill.

Planning permission and where the low water mark changes things

A local planning authority's area extends seaward to the low water mark of medium tides, and development includes building operations on land covered by water. So a slipway running from the bank down across the foreshore is development requiring planning permission, and so are the shore-side works: the access track, the hardstanding, the turning area, any gates or fencing.

Beyond low water the council's jurisdiction ends. A pontoon moored in the channel and the piles holding it may fall outside planning control altogether while still needing a marine licence. This produces the awkward situation where the walkway needs permission and the pontoon at the end of it does not, and the sensible approach is to describe the whole structure in the application anyway so that the council is assessing what will actually be built.

Two categories of permitted development occasionally help. Works by a harbour authority on operational land, and certain works by drainage bodies, have their own rights under the General Permitted Development Order. Neither usually assists a private landowner.

The description of development on the form should name the structure, its length, its construction and whether it is fixed or floating. Vague descriptions on riverside applications cause trouble at the discharge of conditions stage, because nobody can later tell what was permitted.

Marine licensing and the regulator involved

Works below the mean high water springs mark, including the deposit of any substance or object and the construction of any works, require a marine licence under the Marine and Coastal Access Act 2009. In England that is issued by the marine regulator, not by the council.

Some small-scale activities are exempt, and the exemptions are set out in secondary legislation with conditions attached, often including a requirement to notify the regulator in advance. Do not assume an exemption applies because the structure is small. Read the exemption, check every condition, and register where registration is required.

A marine licence application asks for different things from a planning application: navigational safety, the effect on the marine environment, cumulative effects with other licensed activities, and the method of construction, including whether piling will be percussive and what noise it will produce underwater. Migratory fish are a standing issue on tidal rivers, and piling windows are commonly restricted to avoid smolt runs.

Allow several months. The regulator consults, and the consultation list on a tidal river is long.

Flood risk activity permits

Separately, works in, over, under or near a main river or a flood defence need a flood risk activity permit under the environmental permitting regime. On a tidal main river the control distance is wider than on a fluvial one, and works within 16 metres of a tidal main river or sea defence are typically caught, against 8 metres inland.

The permit is about flood risk and the integrity of defences, so the questions are hydraulic rather than ecological: does the structure obstruct flow, does it displace water, does it damage or obstruct access to a defence, can the regulator still maintain the bank.

Some activities are exempt or covered by standard rules, which are quicker and cheaper than a bespoke permit. Check which category your works fall into before designing, because a design that just misses a standard rules threshold is expensive.

The planning application will also need a Flood Risk Assessment, and on a tidal river that assessment has to address the flood zone, the climate change allowance for sea level rise appropriate to the region and the lifetime of the development, and the safety of anyone using the structure during a flood event. Check the current allowances at the time of writing, because they are revised.

Navigation and harbour authority approvals

Most tidal rivers have a navigation authority, a harbour authority, or both, with statutory powers over works affecting navigation. Their consent is separate from the marine licence even though the subject matter overlaps.

What they examine is practical. Does the structure project into the fairway. Is it lit and marked. Does it create a hazard at particular states of tide. Will vessels using it cross a channel. Is there a right of navigation over the foreshore that the works would obstruct.

And there is an ownership question underneath all of this. The bed and foreshore of most tidal waters belong to the Crown, so a lease or licence is normally needed for any structure resting on or over them. That agreement takes months and its terms, including the rent and the reinstatement obligation at the end, affect whether the project is worth doing. Start it early. A similar ownership and consent tangle arises with a residential mooring or houseboat, where the water itself becomes the planning unit.

Ecology in the intertidal zone

Tidal rivers are heavily designated. Estuarine mudflats and saltmarsh are frequently notified as Sites of Special Scientific Interest and designated as Special Protection Areas or Ramsar sites for overwintering birds, which brings the habitats regulations into play and can require the council to carry out an appropriate assessment before granting permission.

Even away from designations, the intertidal zone supports otter, water vole and migratory fish, and the bank supports nesting birds. A Preliminary Ecological Appraisal should be the first ecological step, with species-specific survey following from what it finds. Councils usually expect a suitably qualified author, and where protected species are involved a licensed ecologist is legally required.

Two design decisions carry most of the ecological weight. Open piled structures shade less and obstruct less than solid causeways, and they are far easier to justify. And construction method, particularly whether you pile, dredge or place rock armour, determines the disturbance footprint more than the finished structure does.

Access, parking and trailer manoeuvring

The landward end is where local objections concentrate, and they are usually about vehicles rather than about the jetty.

A slipway that will be used for launching needs somewhere for a car and trailer to turn, wait and park without reversing onto a lane. Work out the swept path for a vehicle and trailer and draw it. Where the access is onto a narrow rural road, the highway authority will want visibility splays measured to the current standard and may want the access widened, which brings the verge and any highway land into the application.

Think about intensity of use as well. A private slipway for one boat is a different proposition from a structure that will be used by a club, and a condition limiting use to the occupiers of the property is a common and reasonable outcome. Say what you intend rather than leaving the council to assume the worst.

Conditions, maintenance and public access

Expect conditions covering construction method and timing, materials, lighting, and often a requirement that the structure be removed and the foreshore reinstated if it falls out of use. That last one is worth negotiating rather than accepting unread, because the cost sits with whoever owns the land when the trigger arrives.

Maintenance access is the practical detail people forget. Timber decking on a tidal structure needs replacing, piles need inspecting, and the marine licence and the seabed lease may both control what you can do without a fresh application. Build a maintenance regime into the Planning Statement so that routine repair is clearly within what has been permitted.

Public rights of way along the bank, and the public right of navigation over tidal water, cannot be extinguished by a planning permission. If your structure crosses a path or a right of access, that needs a separate process and it will not be resolved at the same time.

This is general guidance, not legal advice. Consents for works in tidal waters are specific to the river and the authority involved, so check the position with your local planning authority, the marine regulator and a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. Enter your postcode on PlanScope to see which reports a riverside site is likely to need.