© Duncan Hutt
Big Waters is the largest subsidence pond in the region, formed by the collapse of deep mine workings. Medieval ridge and furrow grassland supports many herbs including pepper saxifrage. Keys are available (to NWT members only, for £10) to gain access to both of the locked hides, which are otherwise closed to the public.
The largest of the South East Northumberland subsidence ponds and one of the largest bodies of open water within the area; the site has surrounding fen and carr. The pond formed in the 1920's as a result of mining subsidence along the Hartley Burn; impounded by tipped colliery shales. Most of the reserve is open water, reedbed and a skirting rim of wet woodland. The lake level varies significantly after rain and as a result many of the paths are on raised boardwalks. The nature conservation interest of the reserve is enhanced by a variety of closely associated habitats including: a meadow with relic areas of rigg and furrow; and a maturing wood planted in the 1960's. Since 1982 volunteer wardens have helped to manage the reserve, maintaining its high profile as a site for birdwatchers and other visitors. Hides (key required, contact the Trust), a bird feeding station and screens allow close observation of wildlife. The reserve has one of the largest colonies of tree sparrows; great tit, blue tit and chaffinch are also regular users. Many of the more common water birds are visible, including great crested grebe, mute swan, coot, moorhen, heron and tufted duck. Occasionally, unusual visitors such as water rail and bittern can be spotted. To the East of the reserve the pond is managed by Newcastle City Council as public recreation area. Great crested newt along with a range of damselflies and dragonflies occur here, including large red and azure damselfly and common hawker. The lake and the quiet reedbeds provide a home to otters.