An interview with...

 David Villis has been the South Gloucestershire Ecologist since 2001 and sits on the Avon RIGS committee. I asked him to tell me a little bit about himself and his involvement in geoconservation in the Avon region.

Hi David. I wonder if you could briefly explain what being the South Gloucestershire Ecologist involves on a day-to-day basis?

I am part of the Strategic Planning Policy and Specialist Advice Team for South Gloucestershire Council. I work with landscape officers, archaeologists and conservation officers and, whilst there to give advice to other Council departments and the public, my primary role is to provide comments to the Development Control and Major Sites teams on planning applications. These range from to new power stations to house extensions.

How did you come to be in your current job?

In terms of academic background, I studied Applied Biology at Hatfield Polytechnic. Immediately after I graduated I managed a record shop for four years, which was great fun!  I started work with the Nature Conservancy Council (subsequently English Nature and Natural England) in the 80s and in 1991 took up the position of Protected Species Officer, working predominantly with bats, badgers, great-crested newts and dormice. It was through this role that I gained an insight into the planning process and that led me to applying for my current job. 

A hibernating dormouse.  Protected Species Officers look after the interests of dormice and similarly legally protected species in the UK. Photo credit: John Robinson/Natural England.

Considering your biological background and ecological job title, how does geology fit into your role?

When a planning application comes in, the first thing we do is locate the proposed development on our GIS database. If an area has previously been recorded as having geological importance, such as a SSSI or RIGS, this will be flagged up and taken into account throughout the application. A lot of planning proposals have low geological impact; landfill and quarry expansions/restorations are generally the most significant issue that we have to consider with regard to RIGS.

You mentioned RIGS and SSSIs – what exactly is the difference between the two?

They are part of the hierarchy of how natural heritage, specifically geology, is defined and preserved. At one end of the scale you have outcrops that are internationally important and are UNESCO World Heritage Sites, such as the Jurassic Coast. Geological SSSIs (Sites of Special Scientific Interest) are considered to be nationally important and can comprise either exposures or deposits; a good local example is Burrington Coombe in the Mendips. The next step down from SSSIs are Local Sites. RIGS (Regionally Important Geological and geomorphological Sites) fall under this umbrella. They represent outcrops that have regionally significant scientific and educational value. 
 

In terms of legal protection, what does the designation of a RIGS actually mean for an outcrop?

A RIGS is a non-statutory designation.  This means that the site doesn’t have any legal standing but is protected from development under the South Gloucestershire Local Plan. Policy L8 of the Plan does not permit development that would cause damage to a RIGS unless the importance of the development is considered to outweigh the value of the affected RIGS, in which case measures will be taken to minimise and offset the impact on the outcrop. As a local authority, we have no influence over the management of RIGS although we of course encourage all landowners to manage them sympathetically.

How does a site in the Avon region become a RIGS?

Technically outcrops can be put forward for designation by anybody, although in reality nearly all are proposed by the Avon RIGS Group. Members of the RIGS Group evaluate any putative site against the criteria for designation and then present it to the Local Sites Partnership (of which the Avon RIGS Group are a member body) for official approval. Their recommendation is then taken by myself and presented to the Executive Member for the Environment for South Gloucestershire Council and, if approved, the information is sent to BRERC (Bristol Regional Environmental Records Centre) for digitisation and inclusion on the GIS database.

Have you been involved in any cases where the geology has significantly impacted on a planning proposal?

A recent success story for RIGS has been Barnhill Quarry in Chipping Sodbury. The quarry was operational from the late 19^th century until the mid-1960s with the Carboniferous limestone being exploited for aggregates and building stone. Extraction of the rock led to the revealing of some magnificent exposures in the quarry walls, including stromatolites, limestone pavement, ripple bedding, dolomitic wadi deposits, thrust planes and an well-defined unconformity between Triassic shales and Carboniferous limestone. Part of the site was assigned SSSI status in 1966, with subsequent audits awarding RIGS designation to the whole quarry.

Exposures at Barnhill Quarry, Chipping Sodbury. Left: Fossil stromatolites in Carboniferous Limestone. Right: Ripple bedding in Lower Cromhall Sandstone. Photo credit: WYG Environment, Barnhill Quarry Geoconservation Assessment

In 2010, we received a planning application to partially infill the quarry and build 170 house plus a large supermarket. Obviously the potential development posed a significant threat to the geology and we had to ensure any construction activities did not destroy important aspects of the site. For example, if any exposures would be covered by the infill, we needed to be satisfied that the characteristics were replicated elsewhere in the quarry wall.

In terms of implementing changes to the planning application, our approach was threefold. Firstly, we made provisions for surveying the site before and during construction activities. Secondly, we incorporated educational features into the proposed development such as an information hut, interpretation boards and a geo-trail, as well as improving public access, which is currently forbidden. Finally, it is essential the outcrops are monitored and maintained, for example keeping rock faces clear of vegetation.

All this is tied into a Section 106 agreement; this means that if the proposal goes ahead, the cost of the conservation measures is met by the developers.

What is your favourite RIGS?

My favourite local geological outcrop is Aust Cliff, a cliff exposure about 10km north of Avonmouth on the Bristol Channel. Not only does it have national significance with great exposure of the Westbury Bone Bed, the colourful strata are visually dramatic. It really is a spectacular sight when driving across the Severn Bridge in the late afternoon with the bedding planes in the rock face highlighted in the low-lying sun. The site accessibility is superb and it’s a perfect outcrop for educational and recreational visits. 

Aust Cliff SSSI, north of Avonmouth, is one of the best exposures in the country of uppermost Triassic and Lower Jurassic rocks. The colourful strata document the transgression of the Jurassic sea over Triassic desert plains. Photo credit: David Villis

Charly Stamper