UNDER THE CITY.

Auckland Star, Volume LXII, Issue 262, 5 November 1931, Page 9

UNDER THE CITY.

SUBTERRANEAN NETWORK.

There used to be told a fairy tale with a moral about a, small boy who would not listen when he was told not to "bolt' his food because it would harm his digestive organs. The little boy one day ° „ ■, ■, • u • x-u a woke to find himself m the midst ol a bewildering confusion of tunnels of all sizes running in all directions. He was much afraid "and only found his way out of the terrible maze with the utmost difficulty. Then he knew somehow that he had become a tiny miniature of Tom Thumb, and was in a human body, lost there because of the disrespect he had shown to his own. - The moral of the story does not matter but were it possible for a man to lit hi*h above the city and see it below him as perfectly "transparent, he would see just such-another orderly tangle of different-sized tunnels, and he would not take so much for granted the ordinary lenittes oflife. ° ■. ~ vr. - +ll To provide the city with W with power, with water, an wi r f vast organisation has een _ 13 7At any street intersection pipes and cables and wires mee , which past somehow. - eP a b we walk throb with t'Tif l mail who merely switches on ligut, or turns a tap for water, fails to realise. or tiuiib d tap An Underground Path.

WATER, LIGHT, SEWERAGE

SERVICES FOR THE PEOPLE

For instance, it is possible for a Gft man to walk upright under the city from one part of the waterfront to the Zoo, at a depth' in some parts of over 100 ft. Forty feet under the ground at different points are chambers large enough to hold a number of men. These are part of the sewerage system of Auckland and the suburbs. In that area there are 8A miles of main sewers, and along much of it it would be possible to walk. At its largest the pipe has an upright section of Bft 6in. That is at Orakei, .while at its smallest, at Avondale, the cross-section is 3ft 6in. The main pipe passes under Albert Park at a depth below the level of Queen Street, while it crosses the main 1 thoroughfare at Victoria Street far be-

low the earth's surface. He tunnel is shaped like an inverted egg, so that when the flow is email it will be more rapid than if the cross-section were circular. In the comparatively lower part of the city are four pumping stations, some 40ft underground. They consist of a storage tank and an outer chamber, in which there is an electric motor. As soon as the tanks fill to a certain height the electrically-driven pumps begin to work automatically, and also cease automatically when the tank contents fall to a certain level. Auckland's Water Supply, - the natural lie of the land /in the lower parts of the city is not towards the main sewer, these pumping stations have been necessary. There is one at Farnliam one at the foot of Con-g-ti-fciation Hill, one in Stanley Street, while the fourth is along Fanshawe Street. All the sewerage from the lower levels is collected by these stations and pumped into the main flow. Besides the eight odd miles of very large sewers, there are also almost 17 miles of subsidiary pipes, feeling their way out all over the city. Beyond these again is the vast network of pipes in every etreet-the reticulation system-. the total length of which it would take a week to assess. The system of Auckland's water supply adds yet another mtricacy to this tangle of pipes and tunnels. These may be called arteries 6f the city They carrv its life blood, so to epeak. But arteries in tMg case, from the Waitakeres to the reservoirs in the city, have a cr oss-seetion of 33in, are of steel, gome take tiiem from the different dams in the ranges to the reservoirs was a feat of gkm _ TunneUi wag exten . 1 *i oAnci t necessary, some of it 800 ft under g roun^i s ome 0 f the piping snakes over the top of the earth,

but all roads lead to Rome— the seven reservoirs in the city. As Auckland is so hilly, they have had to be placed at different levels, from the one at the top of Khyber Pass at 320 ft to that on the shoulder of Mount Eden, at 490 ft. These serve the various areas near them, acting, as it were, as the centre of a great wheel, from which spokes reach out irregularly in all directions.

First Come, First Served. , A* with the drainage, a:ad for that matter every other service, the pipes become smaller the further they are away from the "source of power." When the feeder pipes leave the reservoirs at a depth of . 20ft—the level of the bottom of the reservoir—they are 24in in dia-