Ngauranga Pumping Station
Thousands of drivers pass this point on SH1 every day, but few will know the importance of this attractively designed structure. Despite all these passing motorists, they will not be interested in what you are doing.
The Ngauranga Pumping Station, opened in 1992, plays a key role in the security of supply of drinking water to the Wellington Region. When required, the four pumps are able to draw water from the lower pressure Wainuiomata to Wellington pipelines on the Hutt Road, and deliver it to the higher pressure Kaitoke to Karori system. Water can be pumped from this pumping station towards Karori by way of the Ngauranga 20 million litre reservoir in Maldive St Khandallah, in the hills above, or by reversing the flow direction, back towards Upper Hutt.
Alternatively, if there is an interruption in supply from Wainuiomata to Wellington, water can flow in the other direction, by way of two pressure reducing valves, and supply Wellington city. The diagram below shows these different operational modes.
If you are interested in more information, follow this link to the GWRC publication Our Water History - on tap Water supply in the Wellington region 1867 to 2006 Click here
SPECIAL NOTE
Vehicle access to GZ requires quite a lot of care, coming off the 80km/h highway. Obviously GZ is only accessible from the uphill lanes. If traffic is very light, it is possible to turn directly into the maintenance parking area at the uphill end of the building. Otherwise take the next turnoff into the abattoir and make a left turn back down the hill on the road side of the wall/fence and through the unsealed parking area to GZ. After you have found the cache, exit north at the abattoir and bus stop intersection. If you want to go back to the city, a signposted u-turn is available by following the next offramp to Newlands. Of course pedestrian and cycle access is also available.
You are looking for a camouflaged 500ml screw top container with log. It has adequate space for trackables, and one was left when first published.