The Gatehouse PeldonAn independent guide

Abberton Reservoir

Seven hundred hectares of fresh water in a shallow Essex valley, dug and dammed in the nineteen thirties, and now one of the most important wintering grounds for wildfowl in Britain.

An engineered thing

Abberton is not a natural lake. It was built between 1935 and 1939 and first filled in the year the war began, by damming a shallow valley six kilometres south-west of Colchester, near the village of Layer de la Haye. It covers seven hundred hectares, about seventeen hundred acres, and holds forty-one thousand megalitres. At its deepest it is seventeen metres, though most of it is a great deal shallower than that, which is precisely why the birds are there.

It is owned and run by Essex and Suffolk Water as working infrastructure, not as a nature reserve that happens to hold water. Between 2010 and 2013 it was enlarged in a scheme costing a hundred and forty million pounds, which raised its capacity and connected it to the River Great Ouse in Norfolk through a tunnel fifteen and a half kilometres long running to Wixoe. Water arriving at Abberton may have started a long way from Essex.

The outline of Abberton ReservoirThe shoreline of Abberton Reservoir drawn from Ordnance Survey data, with the campsite marked on its southern shore and the village of Abberton to the east.

The shoreline of the reservoir, drawn from Ordnance Survey data by way of OpenStreetMap. The campsite sits on the southern shore.

Why it matters

Three separate designations sit on the same sheet of water. It was listed as a Ramsar wetland of international importance on 24 July 1981, notified as a Site of Special Scientific Interest in 1988, and classified as a Special Protection Area on 5 December 1991. It also appears in A Nature Conservation Review, the survey that set out Britain's most important wildlife sites.

The reason is arithmetic. In an ordinary winter the reservoir holds around thirty-five thousand birds, and in a hard one that rises well past forty thousand. Three species are there in internationally significant numbers: gadwall, shoveler and wigeon. When a cold spell locks up the water further east in Europe, this is one of the places the birds come.

The oddity is the cormorants. Abberton holds one of the few tree-nesting cormorant colonies in Britain, birds that elsewhere breed on cliffs and stacks sitting instead in the flooded trees along the margins. The colony reached five hundred and eighty-four pairs by 1993 and has since fallen back to something nearer a hundred and eighty.

A haven for bird watchers.

The campsite's own website, on the water at the end of the field

Seeing it

Essex Wildlife Trust runs the Abberton Reservoir Nature Discovery Park on the shore, with a visitor centre, a shop, a café and three bird hides, open daily from ten until five. From the campsite it is the near horizon rather than a journey: the water is what the field looks out over, and the birds come and go across it without anyone having to go anywhere.

The best of it is the cold half of the year. A summer visit gets a large, quiet reservoir; a January one gets tens of thousands of duck on it. The campsite on the southern shore faces straight into that, which is the single strongest argument for the place.

Figures on this page come from published reference sources for the reservoir. The campsite's own former website is the source only for its description of the water as a haven for bird watchers.

Abberton, in figures
Surface area700 hectares (1,700 acres)
Maximum depth17 metres (56 feet)
Capacity41,000 megalitres
Built1935 to 1939; first filled 1939
OwnerEssex and Suffolk Water
Ramsar siteDesignated 24 July 1981
SSSINotified 1988
Special Protection AreaClassified 5 December 1991
Wintering birdsAbout 35,000, rising well past 40,000 in hard winters
Internationally important forGadwall, shoveler, wigeon
Tree-nesting cormorants584 pairs by 1993, now nearer 180
Enlargement2010 to 2013, fed by a 15.5 km tunnel from the Great Ouse
Visitor centreEssex Wildlife Trust Nature Discovery Park, three hides, open daily 10 till 5
PositionAbout 6 km south-west of Colchester, near Layer de la Haye

Where sources disagreed, the claim has been left out rather than hedged.