Getting permission for an open water swimming venue

Opening a lake to swimmers is a material change of use, so open water swimming planning permission is needed for almost any venue that charges, advertises or operates to a timetable. The water itself is only part of it. Changing facilities, toilets, parking and the foul drainage to serve them are the parts that attract conditions, and foul drainage on an off-mains rural site is usually the item that decides whether the scheme works financially.

Change of use of the water and the land around it

Section 55 of the Town and Country Planning Act 1990 defines development to include a material change in the use of land. Converting a fishing lake, a former gravel pit or a farm reservoir into an organised swimming venue changes the character of the use, the number of people on site, the hours and the traffic, so it is a change of use whatever the previous recreational activity was.

The use is normally treated as sui generis, outside the Use Classes Order, which means there is no permitted development route between it and anything else. That cuts both ways. You need permission to start, and you also get a use that cannot drift into something else without a further application.

The red line should cover the water, the bankside, the car park, the facilities and the access, because an application that covers only the lake invites a condition restricting everything that makes the venue usable. Set out the operating model in the Planning Statement: sessions, numbers, season, hours, staffing and whether the venue is members only or open to the public.

The 28 day route, and its limits

Part 4 Class B of Schedule 2 to the General Permitted Development Order 2015 permits the use of land for any purpose for not more than 28 days in total in any calendar year, together with the provision of moveable structures for that use. Many venues start there, running summer weekends with portable changing cubicles and a composting loo.

It is a genuine right and a sensible way to test demand. It is also easy to misuse. The 28 days are cumulative across the calendar year and across purposes, the structures must be moveable rather than permanent, and laying a hardcore car park or installing a drainage field is development in its own right regardless of how few days the land is used.

Keep a dated log of use from day one. Where a venue later applies for permanent permission, that log is the best evidence of actual traffic, parking demand and visitor numbers, and it is worth far more than a projection. The same approach applies to seasonal use of a field, as using a field for camping through the summer sets out.

Water quality and what the authority can control

Water quality is not a matter the local planning authority regulates, and an officer cannot refuse permission because a lake might make somebody ill. What the authority can do is ask how the use will be managed, and environmental health colleagues will take a close interest.

Designation as a bathing water is a separate process under the Bathing Water Regulations 2013, made on application to government, and designated waters are monitored by the Environment Agency. Designation is not a prerequisite for a swimming venue and most inland venues are not designated. Where a venue intends to seek designation, say so and keep the two processes distinct in the submission.

What belongs in the planning application is the management framework: a monitoring regime, the circumstances in which swimming is suspended, how that is communicated, and who holds responsibility. Authorities routinely condition a management plan, so writing a workable one yourself is better than accepting a condition drafted by someone who has never run a session.

Foul drainage for changing rooms and toilets

This is where rural schemes stall. A venue with 80 swimmers on a Saturday morning generates a peak foul load that a domestic septic tank cannot take, and most lake sites have no mains sewer.

The usual answer is a package treatment plant discharging to ground through a drainage field, or to surface water, with the discharge covered either by the general binding rules for small sewage discharges or by an environmental permit from the Environment Agency where the rules are not met. Proximity to the lake is the complication. A drainage field has to be set back from any watercourse or body of water, and on a site where the lake occupies the low ground there may be nowhere compliant to put it.

Resolve that before you design the building. A Foul Sewage Assessment covering peak occupancy, the treatment option, the receiving environment and the set-back distances is the document that answers the question, and on a constrained site the honest conclusion may be that welfare facilities have to be smaller, served by sealed tanks and tankered off, or sited well away from the water.

Ecology, nesting birds and the bankside

A lake with reed fringes, scrub banks and open water is good habitat, and swimming puts people exactly where the sensitive margin is. A Preliminary Ecological Appraisal is the normal starting point, and councils expect a suitably qualified ecologist as the author.

Three issues come up repeatedly. Nesting birds are protected under the Wildlife and Countryside Act 1981 and the season runs roughly March to August, which is exactly the swimming season, so entry and exit points have to be fixed away from nesting margins. Water voles, where present, use the bank between April and September and their burrows are easily destroyed by informal access. And bankside trampling spreads quickly once a desire line forms, so defined entry steps, a boardwalk or a short run of revetment usually does more for the ecology case than any amount of policy text.

New build elements on the site will also engage biodiversity net gain, and the statutory metric has to be completed by a competent person under the Environment Act 2021 regime.

Access, parking and the lane

Rural venues fail on highways more often than on ecology. A single track lane with no passing places and a blind bend near the entrance will attract a highway objection no management plan can cure, and the cost of a visibility splay or a passing bay is often the real constraint on numbers.

Size the parking from session capacity and changeover rather than from an average day, keep overflow on a surface that survives August and February, and show the swept path for the largest vehicle that will actually arrive. Where a venue is on a navigable river rather than a lake, the structures in the water bring a further consent layer, as getting permission for a pontoon or slipway on a river explains.

Flood risk, and the conditions to expect

Lakes and former workings often sit in Flood Zone 3. Water-based recreation without sleeping accommodation is classified as water-compatible development for flood risk purposes, which helps, though changing rooms, a cafe and a car park all need their own assessment of levels, access and evacuation.

Expect conditions on the operating season, opening hours, the maximum number of swimmers per session, approval of a water quality and safety management plan before first use, restriction or prohibition of external lighting, a car park management scheme, and the retention of bankside planting. Offer wording for the numbers and the season yourself, tied to the capacity you have evidenced. A venue that proposes a season of March to October with stated session limits usually keeps them. One that leaves it open gets whatever the committee decides on the night.

This is general guidance, not legal advice. Check the position with your local planning authority or 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. For specialist technical reports, qualified professional input may be required. Enter your postcode on PlanScope to see which reports a recreational use of water is likely to need.