Scottish Water is tunnelling under roads in East Ayrshire to avoid traffic disruption as part of a project to improve water supply.

Scottish Water's £120m investment in the drinking water network aims to improve the supply by installing more than 30 miles of new water mains to connect the system in Ayrshire with the Greater Glasgow network.

Caledonia Water Alliance used tunnel boring machines to install a section of a major a new water main under the A77 near Kilmarnock and to lay another stretch of the pipe beneath the River Irvine near Hurlford.

This approach is continuing to be used in the plan's second phase, which comprises of the installation of 13 miles of water main from Amlaird Water Treatment Works in the Fenwick Waterside area to Highlees Pumping Station near Dundonald in South Ayrshire.

The expanded network will enable Scottish Water to provide customers with greater security of supply and to respond more effectively to operational issues such as burst water mains.

Senior construction manager Sean Lavin said: "When planning the work, we did everything we could to minimise any disruption or inconvenience to road users.

"We recognised how busy the A77 is at this location and that is one of the reasons why we opted to construct a tunnel, which doesn't require any roadworks."

He added: "In addition, although we previously diverted a stretch of the Craufurdland Water further north to install a stretch of the same water main beneath the river bed and we decided to tunnel beneath the River Irvine at Hurlford.

"At all times during this project, we try to do whatever we can to minimise disruption to road users and the natural environment."

The construction of the new strategic water main is expected to be completed in 2020.