Far-Sighted Project

Sun (Auckland), Volume II, Issue 557, 9 January 1929, Page 8

Far-Sighted Project

North Shore Sewage Difficulties

AFAR-SIGHTED scheme, and one which Presents many engineering difficulties, is progressing steadily on the North Shore, where the people are being given the benefits of a sewerage system costing, when complete, something in the vicinity of The uncertain nature of the country has created many hazards for those in charge of the job, but four years of solid work lias produced a gratifying change in the sanitary service in the seaside districts.

The project to provide a comprehensive sewerage system for Takapuna, Bayswater, Belmont and Milford was at first regarded as almost too ambitious to be undertaken by the Takapuna Borough Council, for the awkward lay-out of the locality was known to embrace many constructional difficulties, and it was considered likely that trouble would be experienced in getting the hack-bone of the sewer laid. But that was four years ago. The progress made with the enterprise in the meantime has been clearly indicative of a sound and profitable ven-

35 % -:p Hr % * at a as Hi 3K * * rr ture, and in a comparatively short time the residents of the North Shore districts will be grateful that the civic authorities decided to proceed with it. In some places near the waterfront the laying of the main line sewer had to be taken through solid rock, and blasting operations were necessary to ensure an efficient job. Nearby the construction gang would find a stretch of loose sand which presented the greatest difficulty in the laying of a three-foot pipe, because of frequent earth-falls. Again, trouble was experienced because both sides of the Takapuna ridge had to be served, and a drop was necessary from the east side subdivisions to the outfall into the sea oft' Takapuna Beach. One by one these difficulties were overcome. Steady progress was made with sinking the main sewer line, rocks were blasted where the way was blocked, and sand was boarded up where deep drains were being dug as a resting ground for the big pipes.

A suggestion that storage tanks be built off the rocks between Takapuna and Milford did not receive favour from the engineer to the Borough Council, Mr. Archibald Slinger, who pointed out at the time that the buoyancy would spell disaster to the scheme if they were constructed. Storage was then arranged for in a long line of pipes, 6ft in diameter, which has been built around the seafront and which acts in the threefold capacity of an erosion defence, a sewage store and an embankment for a future waterfront promenade. EAST TO WEST TUNNEL The service from the east side of the ridge was dealt with by a tunnel, well over a mile in length and 6ft in diameter, stretching at 10ft below sea level, through the hill from Shoal Bay and emerging at the bottom of St. Leonard’s Road, to be then conveyed 600 ft into the Rangitoto Channel to the ultimate outfall. This tunnel was an engineering feat of some magnitude for the small borough. It was estimated by the engineer that it would occupy two hours and 17 minutes to empty. When it was tested three weeks ago the emptying time was exactly two hours and 20 minutes —three minutes over the estimate, three minutes which could be added by wind or tide. The storage sewer along the waterfront, which cost about £17,000 to build, has accomplished splendid work in protecting the properties on the Takapuna and Milford foreshore, and if Mr. Slinger’s shore road is constructed eventually, will assist in making one of the most picturesque drives in New Zealand. CONNECTING UP RAPIDLY While these main lines were being put down, and elaborate provisions made for the ultimate disposal of the sewage, reticulation of the areas to be served was pushed on. Central Takapuna is now complete, Belmont and Bayswater are ready for connection to the system and the council estimates that by the end of the current summer the people of Milford will possess the advantages of the new scheme. The preparation of the outfall has entailed a great deal of time and work, and although good progress has been made with its construction, the job cannot be completed until the arrival from overseas of some of the material about the middle of Januarv. Ever since the establishment of ordered municipal administration on the North Shore, about a decade ago, sanitation has presented profound difficulties, and residents have always lived in hope that some project would be launched to solve their problem. This project has been more than launched; it has been in the course of construction for four years, and in the not distant future the whole area will be served, and the Takapuha Borough Council may then claim special mention in New Zealand municipal records for the success of its undertaking.