Manton Dam
Manton Dam is adjacent the Stuart Highway and its a great place for a swim or a picnic, or for canoeing or windsurfing. However, not so very long ago it was a vital facility in Darwin's water supply system.It may be difficult to imagine now, but until 1939, when Howard Springs water was piped into Darwin, the town was dependant on private wells, bores, and household tanks which stored run off from roofs. Even the supply from Howard Springs didn't solve the problem - there was no water on Sundays because the pumping engine didn't run!
Sometimes there had been serious shortages, as in 1934 when water had to be strictly rationed and ships in the port were unable to get any water at all. In 1937 there was a crisis when a water spout dropped salt water on the town, contaminating supplies.
The problem became more acute in the late 1930s when defence construction works brought many workers to the town and boosted demand for water on project sites. Underground supplies diminished because of heavy pumping from them. At one time there was not enough fresh water to mix the concrete for Larrakeyah Barracks construction!
Something had to be done. In 1937 a dam site on the Manton River was selected, then in 1938 tenders were called to construct the dam and a twelve inch pipeline to bring water to Darwin. Work began early in 1939 and good progress was made until 1940 when there was recurrent industrial trouble.
The dam was ready to hold water during the 1940 wet season, although it was not finished until late 1941. The first water from the dam was pumped to Darwin on 11 March 1941. In the meantime, from 1939, water had been pumped across from Howard Springs into the new pipeline from Manton Dam and thus Darwin's most urgent needs were met.
When the war with Japan broke out in December 1941 there were frantic efforts to protect the dam wall against air raids. Had a bomb burst the dam the resultant water shortage would have been catastrophic, because the population in the Darwin area was increasing swiftly as men were brought in to resist the anticipated Japanese invasion.
The first step was to install anti-torpedo nets to protect the dam wall. Then a heavier steel net was stretched across the dam, supported by floating drums and anchored to large steel towers on either side. Finally, in 1943, anti-aircraft searchlights were installed.
After the war the dam was handed over for civilian use and a second pipeline was installed to service Darwin's growing population and increased water use with the extension of sewerage schemes.
From 1964 the Manton Dam water was supplemented with about 10% bore water from the McMinn's Lagoon borefield. However, Darwin was growing rapidly and a second dam was necessary. In 1972 the Darwin River Dam, eleven times larger than Manton Dam, was opened. Subsequently, Manton dam was made available for recreational use.