Plans to develop a Pembrokeshire farm for dairy use by its new owners have been approved despite objections it would probably be the largest on coastal land in the north of the county.

In an application recommended for approval at the September meeting of the Pembrokeshire Coast National Park Authority’s development management committee, Christopher James, of Stackpole Quay Farm, through agent Cynllunio RW Planning Ltd, sought permission for a milking parlour, a collecting yard, feed pad, silage clamp, dirty water lagoon and associated works at Longhouse Farm, Abercastle Road, Trefin.

A supporting statement accompanying the application said: “The family are in the process of establishing a spring calving herd of 360 dairy cows plus 90 followers. The herd will be grazed all year round, in the spring, summer and autumn on grass, and in the winter-on-winter forage crops. The system will be a low input low output system seeking to utilise as much grass as possible to create quality milk.

“A key element of the proposal is an efficient dairy operation which includes a milking parlour, collecting yard, feed pad and silage clamp. A dirty water lagoon is also required to collect the slurry/dirty water from the collecting yard and feed pad and to store effluent from the silage clamp and parlour washings from the dairy.”

An additional application associated with the development, a cattle underpass, is currently running.

An officer report highlighted a number of objections to the scheme, including that “the proposal represents a significant intensification from sheep/arable farming to an intensive dairy operation, with associated environmental implications,” adding: “Objectors also question whether potential future herd expansion should be considered now.”

The report stressed “no planning permission is required to change the use of an agricultural holding from beef sheep or arable to dairy farming,” and: “The principle of agricultural buildings is supported where they are necessary for agricultural purposes on the holding. Any future related development would require a separate planning application.”

Speaking at the meeting, local objector Paul Nevinsky said the scheme would result in a dairy farm “twice the average size,” which would be “probably the biggest on coastal land in north Pembrokeshire”.

Call for strict conditions or for a site visit before any decision was made, he raised concerns of the size of the herd, the size of the slurry lagoon and visual impact, describing the lagoon as “three times the size of an Olympic swimming pool”.

Applicant Mr James said he had farmed at Stackpole for decades and expected this scheme would increase biodiversity, with the proposals actually seeing a decrease in building heights.

He stressed there was no intention to increase the size of the herd.

The recommendation of conditional approval was moved by Dr Rosetta Plummer, with nine members in favour and two against.