The extension was undertaken on behalf of Scottish Water by Black & Veatch which increased the height of the reservoir walls by 2.5 metres and used a unique ‘piano key weir’ extension for the overflow weir.
Project manager Jim Tudhope said in a statement that the weir expansion consists of 24 pieces of cast concrete, “each the size of a portacabin” which “to the casual observer has the appearance of a large plughole”.
“This is believed to be one of the first times such an approach has ever been undertaken anywhere in the world. The weir design adds to the operational efficiency of the reservoir, and also enhanced safety for the construction team,” Tudhope added.
Local councillors welcomed the completion of the expansion project as a key benefit for surrounding communities.
“This has been a very successful project, delivered under budget and on time, with good environmental and health and safety standards,” said councillor Archie Dryburgh.
Councillor Craig Peacock added: “Anything that Scottish Water does like this to increase capacity and supply to customers is welcome as it will benefit the communities in the area for years to come.”