There are five notice boards giving information on Wilstone (and other) reservoirs. Selected Extracts. WATER STORE & WILDLIFE RESERVE: As boat traffic increased on the Grand Union Canal so did the demand for water to refill the locks. By 1802 spring water supplies could no longer keep pace with this demand and so Wilstone Reservoir was constructed. The reservoir was created by building retaining walls to trap water from chalk streams and springs. It was enlarged in 1836 and again in 1839, and today stores around 240 million gallons of water. When this water is needed it is channelled through underground culverts into a 23 metre (75 foot) deep well below Tringford Pumping Station. It is then pumped into the Wendover Arm Canal to flow to Tring Summit. WILSTONE'S WILDLIFE. The reservoir's mix of deep and shallow water, reedbeds and marsh make it a wonderful place for wildlife. Whilst the reservoir is owned by British Waterways, it is managed by Herts and Middlesex Wildlife Trust. Projects to encourage wildlife include cutting the reed beds to stimulate growth, installing floating rafts of gravel to entice terns to nest and retaining grassy banks, favoured by water voles. A NATIONALLY IMPORTANT SITE FOR BIRDS. Around 250 different types of bird have been recorded here including some rare species, like osprey and little egret, which call in to rest and feed on their journeys elsewhere. Willow warblers and sedge warblers are attracted by the reed beds, whilst herons nest in waterside trees. UNDERWATER RECORD-BREAKERS. Wilstone Reservoir is also an important fishery, managed by The Tring Park Estate. Record-breaking catches include a 15.9kg (35lb) pike and a catfish which measured 1.69 metres (5½ feet) long! Other fish to be found here include tench, bream, roach, perch and rudd.