It serves as a memorial to what was the largest public works project of its time, and is registered as a Category I structure by Heritage New Zealand.
[1][5] The 723 larger pipes had an internal diameter and a length of 3.7 m (12 ft), a wall thickness of 250 mm (10 in), and weighed 28 t (28,000 kg) each.
[1][6] As far as is known, these were the second-largest spun reinforced concrete pipes manufactured in the world up to that time,[4] exceeded only by those used in the United States for irrigation from the Colorado River and the water supply system for Boston.
[1] The minister of public works, Bob Semple, was an enthusiastic supporter of the project and drove his car into the first pipe laid at Surrey Hill.
In order to store explosives at this site, one of the RDR pipes was installed at the works camp using as a base a pre-cast control gate for the water race.
[1][8] The exterior is in good condition apart from a crack in the panel above the vent, but the internal floor has deteriorated, and the door is a replacement.
It is accessible through a gap in bushes and trees from Main Street, or via The Garden Of Harmony, a reserve on South Belt.