The boardwalk trail at Wilderness Island Nature Reserve. Image copyright London Wildlife Trust Kingfisher. Image copyright RSPB Images

Upper River Wandle

Merton, Sutton

Grade: Metropolitan | Area: 57.89 ha


Free public access (all/most of site)


Despite reductions in flow caused by the regular removal of water for industry, the River Wandle is still one of the finest chalk streams in London (chalk streams so-called as they are fed by water from sources rising in chalk). The river has natural banks for much of its length within this site and supports abundant bankside and aquatic vegetation. This extends into various wetland sites alongside the river, sometimes developed on disused watercress beds.The site includes four Local Nature Reserves. Wilderness Island is owned by Sutton Council and run by the London Wildlife Trust and is always open - volunteer management workdays are on the last Sunday of the month. Spencer Road Wetland, again owned by Sutton and run by LWT has only restricted access, although workdays are on the first Saturday of the month (call 020 7261 0447 for further details). Bennett's Hole and Ravensbury Park are both owned and run by Merton Council.


The exceptionally diverse aquatic plantlife includes the London rarities chalk stream water-crowfoot, horned pondweed, opposite-leaved pondweed, arrowhead and unbranched bur-reed. Small areas of wet woodland occur at various places beside the river. Other uncommon plants on the site include ragged-robin, marsh-marigold, sharp-flowered rush and water chickweed.There is a large and diverse fish community, which includes dace, chub and bullhead. Breeding birds include kingfisher, grey wagtail, blackcap, chiffchaff and reed warbler. Wetland insects include several nationally rare moths as well as many species of butterfly including speckled wood, holly blue and comma.Wilderness Island: In the woodland occur horse-chestnut, some large crack willows and black poplar. The meadows support over 70 species of wildflowers, with vervain particularly noteworthy. An unusually large sedge bed is made up of both greater pond-sedge and pendulous sedge. The meadow areas also support a variety of insect life, such as Roesel's bush cricket and several butterflies.


Car parking; cycle paths; historic features; information; nature trail; waymarked walking route.


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