Scotland's biggest sewer superstructure, the Shieldhall Tunnel, is now operational.

The £100m tunnel which runs under Glasgow was constructed over two years by a team of more than 100 workers.

Built using a state-of-the-art tunnel boring machine (TBM) weighing 1000 tonnes, the three-mile sewer is designed to prevent flooding.

Scottish environment secretary Roseanna Cunningham officially "switched on" the tunnel at a ceremony on Monday morning.

The Shieldhall Tunnel is five times longer than the Clyde Tunnel and will help stop floods in Mount Florida, Toryglen and Giffnock.

It will do this by storing up to 90,000 cubic metres of storm water during periods of heavy rain and releasing it later on.

This amount of water is the equivalent of 36 Olympic-sized swimming pools.

The tunnel is the flagship project in Scottish Water's £250m, five-year programme of investment in the Greater Glasgow area's waste water infrastructure - the biggest in more than a century.

It aims to improve river water quality, to enable the area to grow and to tackle flooding and the effects of climate change.