The Carrs is a Site of Special Scientific Interest

Site of Special Scientific Interest

A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...

 in the Sedgefield

Sedgefield (borough)

Sedgefield was, from 1974 to 2009, a local government district and borough in County Durham, in North East England. It had a population of about 87,000 . It was named after Sedgefield; but its largest town was Newton Aycliffe...

 district of County Durham

County Durham

County Durham is a ceremonial county and unitary district in north east England. The county town is Durham. The largest settlement in the ceremonial county is the town of Darlington...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. It is situated on the eastern outskirts of Ferryhill

Ferryhill

Ferryhill is a town in south-central County Durham, England with a population of around 11,651 people, making it the 8th biggest town in the County. It is in the Durham County Unitary area...

, between the town and the East Coast Main Line

East Coast Main Line

The East Coast Main Line is a long electrified high-speed railway link between London, Peterborough, Doncaster, Wakefield, Leeds, York, Darlington, Newcastle and Edinburgh...

 railway.

The Carrs is an area of wetland that has formed in the low-lying parts of a glacial meltwater channel. A large part of the site is open water, which is fringed by fen

Fen

A fen is a type of wetland fed by mineral-rich surface water or groundwater. Fens are characterised by their water chemistry, which is neutral or alkaline, with relatively high dissolved mineral levels but few other plant nutrients...

 vegetation. Woodland and calcareous

Calcareous

Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...

 grassland cover the steep slopes on the western side of the site, where there is also a disused quarry.

The site's importance lies mainly in its areas of open water and fen vegetation, which are scarce habitats in lowland County Durham. There is also a small area of equally scarce magnesian limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 grassland, in which blue moor-grass, Sesleria albicans, and glaucous sedge, Carex flacca

Carex flacca

Carex flacca, with common names blue sedge, gray carex, glaucous sedge, or carnation-grass, , is a species of sedge native to parts of Europe and North Africa....

, are dominant.

The site adjoins the Ferryhill Carrs Local Nature Reserve

Local Nature Reserve

Local nature reserve or LNR is a designation for nature reserves in the United Kingdom. The designation has its origin in the recommendations of the Wild Life Conservation Special Committee which established the framework for nature conservation in the United Kingdom and suggested a national suite...

, which extends to the north, alongside the railway line.