Gauge basins, Craigmaddie Reservoir, Milngavie.

Milngavie Water Treatment Works are the primary source of water for the city of Glasgow and the Greater Glasgow area. Part of the Victorian Loch Katrine water project, construction of the first reservoir at Mugdock was started in 1855 and opened by Queen Victoria in 1859, replacing the previous water supply sourced from the River Clyde at Cuningar Loop in Dalmarnock.

Its completion led to the virtual eradication of typhoid and cholera, diseases which were widespread at the time, from the city. The success of the project was marked by the erection of the Stewart Memorial Fountain in Kelvingrove Park. The works were described by James M. Gale as worthy to "bear comparison with the most extensive aqueducts in the world, not excluding those of ancient Rome".

Craigmaddie Reservoir was opened in 1896 to cope with increased demand. Gauge basins take the water from the underground aqueduct and pass it from one section to another through apertures at the bottom of the walls. This checks the force of the water as well as stilling it before it enters the adjoining measuring pond or basin where the quantity passing into the reservoirs each day is measured.

There is a new, third, reservoir named the Bankell Reservoir, which went into operation in 2006. Most people don't know it is there because although it holds 20 million gallons the Bankell Reservoir is 80% underground to minimise ecological impact. It is one of the largest treated water holding tanks in the world.

The new reservoir and treatment works were developed in the wake of the discovery of the waterborne cryptosporidium parasite in Mugdock Reservoir on 4 August 2002, as a result of the 2002 Glasgow floods. Cryptosporidium can cause severe diarrhoea. About 140,000 people in Glasgow were affected, they were told not to drink tap water without boiling it first.

The works are currently operated by Scottish Water and at average demand, it can supply enough potable water to those it serves for up to 7 days. Its primary supply is via two aqueducts from Loch Katrine in the north, that are 35 miles in length, and can deliver up to 50,000,000 gallons a day. Milngavie itself is situated at almost 400 ft above sea level - sufficient to provide adequate water pressure to the majority of Glasgow without the need for pumping. The Milngavie reservoirs distribute water to secondary reservoirs, such as Cockmuir Reservoir in Springburn Park, and various Water towers throughout the city.