The pump house at Mt Para was part of the Baring Head / Ōrua-pouanui water supply system, not part of the main Wainuiomata town waterworks. Its job was to lift water from the Wainuiomata River up to the high ground of Para Hill near Para Trig, where the military observation post and related wartime buildings stood.
The actual pump house is down beside the Wainuiomata River, on the true right bank, about 300 metres from Coast Road and about 800 metres south of the access bridge to Baring Head. From there, pipes climbed the hill to Para Trig. A concrete storage tank near the top held the water before it was distributed to the military buildings, and later down towards the lighthouse station and naval signal station.
The system appears to have been built around 1940, when extra accommodation and services were added for the Fortress Observation Post. Water was carried uphill through 1.25-inch galvanised pipe to a concrete tank above the barracks and wireless room. From that height, gravity then provided enough pressure to feed nearby structures.
Its main purpose was practical: men stationed on the exposed hilltop needed a reliable water supply. The site around Para Trig included the observation post, wireless room, possible mess room, barracks, ablutions area, and associated military infrastructure. The observation post itself had been built in 1935 and was later used during the Second World War in connection with Wellington’s coastal defence network.
After the war, the water supply did not immediately disappear. The system passed into Marine Department use, and water continued to be pumped to Baring Head for some time. The exact date when it stopped operating is not known. The pump house remains in place, along with sections of galvanised pipe and the concrete water tank near Para Trig.
