84
50. The Mainland already makes a considerable contribution to the City's water needs and in view of this being the only source from which increasing require- ments can be obtained, the importance of the security of the Cross Harbour Pipelines, already great, will gradually become more and more vital.
Proposed Alterations, Improvements and Extensions to Lines of Communication,
Island.
51. In view of the above and the present condition of these pipelines the follow- ing proposals are made:-
(a) The present 18′′ main should be provided, as early as possible, with a more
permanent protective coating to arrest corrosion.
(6) As the 12′′ main may fail at any time and as supplies of a greater amount than the capacity of the present 18′′ main are now required, a new 18′′ main should be laid as early as possible.
(c) In view of their vulnerability, the pipelines should be protected by a covering or other expedient to guard against any reasonable possibility of damage or dislocation by shipping.
52. In order to provide more flexibility in emergency, to relieve the Eastern resources and to make fuller use of the present supplies available from the Main- land, the water from the latter will need to be delivered to a higher level than at present, i.e. to Albany. This will necessitate (d) the extension to Albany Service Reservoir of the main now supplying the Gardens Service Reservoir, (e) the installa- tion of pumps at a suitable point to ensure delivery to Albany in sufficient quantity through this main (d) and (f) the replacement of the 12" dia. section of the Albany Elliot main by one of 18" dia.
53. It will be observed from the plan that the "Line of communication" from the Eastern source enables water to be delivered to any part of the City. The im- portance of this, in the absence of the supply from the Mainland through break- down or other cause, is therefore obvious. Water, though of limited amount, could be supplied to all districts.
54. It is therefore proposed that (g) the Bowen Road Conduit be reconstructed. Pumps would be installed at Eastern with the second set of new filters proposed in para. 71 (b) and these would pump water from these filters back to the Conduit and thence to Bowen Road Service Reservoir.
55. The reconstruction of this conduit would enable Bowen Road to be used for motor traffic.
56. Similarly in the absence of supply from the Eastern resources a limited amount of water could be provided to all districts from the Mainland by means of the pumps proposed in para. 52 and designed for the dual purpose. These would be designed to deliver water through the reconstructed Bowen Road Conduit in an easterly direction as far as the Eastern Filters and in a westerly direction to Elliot by means of Albany-Elliot Main.
57. The interconnection at Albany of the Eastern and Mainland lines of communication would obviate the total absence of supply in emergency in all districts.
58. A breakdown in the "Line of Communication" of the Western resources would not seriously affect the general supply in the City as these resources are of small amount compared with those of the Eastern and Mainland.