Colne Valley
Colne Valley
Road: M25 between J15 and J16Location: Iver, Iver Heath, Buckinghamshire
Developer: Welcome Break


Colne Valley is an unusual project resulting from a partnership between Welcome Break and Buckinghamshire County Council.
In February 2020, it was revealed that the two were in discussions about Welcome Break leasing the land, which would raise some money for the council and provide Welcome Break an opportunity to open a new site.
As a result, Welcome Break has drawn up a detailed plan for Colne Valley services. It is designed to handle a lot of traffic, and the initial plan showed a very high capacity layout with two lanes from the motorway to the car park, a small web of flyovers and one of the largest range of facilities in the UK.
A thorough rethink of the internal layout in June 2021 saw it scaled back a little, creating something that is still very large, but slightly more in keeping with other service areas on major motorways. No official reason was given for the change, other than that the revised plan increases the distance from the M40 and comes closer to the minimum specification. That last point is likely to be key, as the outcome of this planning application will ultimately come down to whether inspectors believe that the harm that it does can be justified.
Trivia and Design
Access would be provided from a new, dedicated interchange on the M25. This would involve a dual carriageway flyover, which would be attached to Slough Road, replacing the existing bridge. The M25 here is already due to become a five-lane 'smart motorway', but under this proposal the developer will pay for the M25 between the new service area and the M40 to be widened to become a six-lane 'smart motorway'. This would make it the widest length of road without a hard shoulder in the UK.
Access to and from the M25 southbound would use a new flyover, landing on the western side where a small roundabout would be provided. This roundabout would also provide access to and from the M25 northbound, via two slip roads with very sharp bends.
A single entry road would then branch off, separating cars from HGVs. An access road would run around the back, providing access to the parking for HGVs, coaches and caravans. These roads would then regroup before the roundabout, where a fuel filling station and drive thru coffee shop would be available. Emergency vehicles would be able to use a dedicated access from Slough Road, but staff would only be able to use it when walking or cycling. The emergency access would allow the 'secret exit' further down the M25 at Palmers Moor Lane to be closed.
The proposed amenity building would have a 'sawtooth' roof with solar panels along it. A long, grass canopy would run along the front. Next to the amenity building would be a large plaza, as well as a dog walking area.
In total 941 car parking spaces would be provided, including at least 100 electric vehicle charging points, making it the largest provision on the motorway. 150 HGV parking spaces would be provided. These figures are both very close to the minimum requirements, which call for 939 car parking spaces and 142 HGV parking spaces. There would also be 20 pumps for cars in the filling station, and 5 for HGVs.
Around 500 jobs are expected to be created, and construction would be expected to take around 16 months. The council added that a large tree planting programme should make the project "carbon negative", and that the woodland around the site boundary would be protected from development.
A formal request for planning permission was lodged with South Bucks District Council in January 2021. Considerable local outrage has built up, as residents feel there are a number of infrastructure projects in the Colne Valley area.
Planning History
See also: M25 Planning Applications
When the planning application was made in December 2020, the layout was considerably different.
Two roundabouts would have been provided, one handling all the traffic entering the service area, and one handling all the traffic leaving. This would have been made possible with longer slip roads and a supplementary flyover - a very rare feature in a private development - as the slip roads all untangled. A constrained area between the two roundabouts would have contained the car filling station, a drive thru coffee shop, and a drive thru restaurant.
The car park would have been larger, with almost 1,100 parking spaces, and 200 for HGVs. While the main building would have been similar, it would have had a hotel attached to it. Unusually, the HGV parking area would have included its own dedicated amenity building, with a gym and other facilities.
Regardless of what the decision is at Colne Valley, the M25 through here has a long history of failed service area proposals, generally dating back to before the road was built. These included the Department of Transport's original insistence that a service area be built at Iver, and more recent private proposals at Elk Meadows and Woodlands Park - only a few hundred metres from this site.
Right now there are three service areas proposed near here. Alongside Colne Valley is Moto's Kings Langley and Extra's Warren Farm. The latter already has an inquiry scheduled for August 2021.
Technically, there is no reason why all three couldn't be built, but the planning authorities are likely to rule that only one would be necessary. The involvement of Buckinghamshire County Council implies that the Colne Valley proposal wouldn't have any objections from them, although planning matters are rarely that straightforward.
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