A balancing lake is a lake used to control flooding by temporarily storing flood waters. Before the development of the “New City” of Craigavon the area of land between Lurgan and Portadown was farmland and heavy rainfall which soaked into the ground was released relatively slowly into sheughs and streams eventually making its way via the Pound River and the Closet River to Lough Neagh at Oxford Island.
As the central areas of Craigavon – Brownlow and then Mandeville – were developed the increase in hard surfaces i.e. roofs, roads and footpaths meant that rainfall was dumped immediately into the storm drainage system. If left unchecked, this would have resulted in a surge causing flooding downstream. The balancing lakes were engineered to contain this surge and release it slowly minimising the impact on an obvious bottleneck where the Closet River runs under the M1 and M12 near Kilvergan and beyond that where it flows through an area of particularly flat land alongside the motorway before it turns north into Lough Neagh.
Thankfully this rather mundane but necessary balancing has resulted in an exceptional area of parkland which now supports some rare orchids and a wide variety of wildlife including fish, birds and otters, as well as offering great opportunities for water sports, walks and cycling. The mountain bike tracks may not be designed for walkers but at quiet times they provide a delightful route through the maturing woodland. Tannaghmore Gardens Farm/Museum and play area to the north of the lakes offer great attractions to families. Craigavon Civic and Conference Centre overlooks the lake in the south-west corner and its neighbour, the South Lake Leisure Centre, is a recent valuable addition.
The Closet River flows into the south-western corner of the South Lake - at the stepping stones close to the Leisure Centre. The outlet from the lakes is at the north-western corner of the South Lake where it flows into a culvert under the railway line reappearing on the northern side of the line as it again becomes the Closet River.
Footnote: Before the completion of the Balancing Lakes in the early 1970s the author recalls walking across the dry clay bed after the excavators had completed their work, observing kingfishers by the Closet River close to the site of the Civic Centre and listening to skylarks and a corncrake.