What is ‘special’ about Cors Goch SSSI?

Cors Goch has 9 special features:

As well as the features listed above, Cors Goch has other habitats/earth science features that contribute to the special interest. These include wet heath, scrub and bracken, together with hedgerows, streams, small rock outcrops or individual trees. This mixture of habitats is important for much of the wildlife including great crested newts, adders etc., and these too are key components of the special interest of the site. Unless specified below, management of this site should aim to look after these habitats as well as the listed features of interest.

What do we want Cors Goch to look like?

The site should continue to have at least 25 ha of swamp and “open” fen (largely without scrub or tree cover), characterised in part by great pond- sedge and elsewhere by mixtures of black bog-rush and blunt-flowered rush, or swamps of bottle sedge and brown mosses. Small patches of bare peat and open water within the fen will be encouraged for the benefit of medicinal leeches and stoneworts. Patches of willow and birch scrub can be tolerated but should not exceed 10% of the fen area. Areas of heathland, characterised by heather and western gorse should be maintained with a diverse structure, including between 10% and 20% of bare ground to permit pale heath violet to thrive. The calcareous grassland, characterised by green winged orchid, should be maintained at a minimum of 0.2 ha. The lake should continue to support typical clear water aquatic and emergent species. The site will provide habitat for breeding great crested newts and a rich assemblage of invertebrates including dragonflies, marsh fritillary and medicinal leeches.

What management is needed on Cors Goch SSSI and why?

Although Cors Goch is an excellent place for wildlife and geology it will only remain so if the necessary management continues. CCW’s aim is to work with you to ensure that this management is carried out.

What does this mean in practice?

There are many factors that could damage the special features at Cors Goch if they are not properly managed. These are the ones we regard as most important:

Water level: A high water table is essential for swamp and fen plants and animals. It is therefore important that outfalls from the site are not deepened or widened to increase their capacity. Past drainage works may have affected the site and a weir or sluice could help to protect water levels, buffering the site against river works downstream. Regional groundwater in the aquifer is important in maintaining the water-table and the flow of springs. Thus actions within the catchment leading to a lowered water-table such as de-watering of quarry workings could have adverse effects

Water quality: High water quality (particularly the concentration of calcium and magnesium and low levels of nitrogen and phosphorus) is essential for maintenance of the swamp, fen and aquatic plants and animals. If nutrient levels increased, populations of tolerant species such as floating sweet-grass could increase at the expense of less common (and more desirable) species. Toxins could alter the balance of microscopic plants and animals, especially in the lake, leading to the loss of many species including fish.

Water movement: In addition to the quantity and quality of water, movement of groundwater from springs through the site is essential for the distinctive of fen here and requires great care in the management of water supply and levels

Grazing removes accumulated plant material and is important for swamp, fen, heath and grassland. The fen was formerly cattle grazed and as a result appeared much more open. Grazing by cattle, ponies or donkeys, particularly in spring and summer, helps to limit scrub development and maintains open areas within the fen and heathland. Livestock in the fen also provide food for the medicinal leeches.

Scrub control: Scrub has a role in provision of bird nest sites and shelter for invertebrates, but too much can alter the nature of the site. Should the grazing be inadequate to limit scrub growth, active scrub control may be necessary.

Fire: Although fire was used in the past to clear old growth from the land, uncontrolled fires can damage the invertebrate community and on heathland may encourage the spread and dominance of western gorse. A planned rotation of small controlled burns in winter may be used to rejuvenate patches of heath and fen. Burning must be followed by appropriate grazing. Firebreaks are required to enable control to be maintained and prevent the spread of wildfires

Cutting / Mowing: Cutting or mowing of heathland can open up dense dwarf-shrub vegetation but should be followed with grazing. Mowing / cutting is a recommended alternative to burning where western gorse is a problem. Cutting is often used in the first instance to provide firebreaks. Cuttings must be removed from the site.

Peat cutting: In former times, hand cutting of peat for domestic use occurred on the site as evidenced by shallow depressions that now contain many species of importance. Small scale excavation may be justified to rejuvenate these areas and provide early successional stages.

Public access: There is access along public rights of way and on the boardwalk installed by the North Wales Wildlife Trust. This is to be welcomed, to help increase public understanding and appreciation of the site, but must be managed so as not to damage the features of interest.


Our knowledge of wildlife is far from complete. It is possible that new features of value may appear and new management issues may arise in the future, whilst other issues may disappear. This statement is written with the best information we have now, but may have to change in the future as our understanding improves. Any information you can provide on the wildlife of your site, its management and its conservation would be much appreciated.

If you would like to discuss any aspect of your SSSI, or have any concerns about your SSSI, please contact your local CCW office.

Your local office is;

Cyngor Cefn Gwlad Cymru/Countryside Council for Wales

North Region

Llys y Bont,

Ffordd y Parc,

Parc Menai,


Gwynedd, LL57 4BN,

Telephone: 01248 672500

Fax: 01248 679259