27
of dealing with, in addition to the yield of the streams already taken into account. This will add 48 days' supply to that already available, bringing the total up to 233 days' supply of 4 million gallons.
9. This proposal will, I feel sure, commend itself to Mr. CHADWICK. The advantages of it are as follows:-
(1.) The site is a very favourable one for the construction of a dam.
(2.) It can be undertaken at once.
(3.) It will not interfere with any existing or proposed works.
(4.) The base of the dam being 112 feet above Ordnance Datum, it will not be overlapped by the construction of the larger dam to be un- dertaken hereafter and will therefore be of permanent benefit for storing water.
(5.) Being close to the small dam in connection with the temporary pumping plant already established, the work people can be con- veniently housed below the latter so as to avoid the risk of pollu- tion of the supply from this source.
10. The remaining works to which I have to refer are designed with a view to the carrying out of the complete scheme for developing the Tytam Tuk Valley and are shown on the accompanying plan. They comprise :
(a.) The formation of a site for the Pumping Station near the head of Tytam Bay and the erection of the necessary buildings to accom- modate the engines already ordered.
(6.) The construction of a new road contouring the lower part of the valley at an elevation of 130 to 150 feet above Ordnance Datum and then ascending to join the existing road near the new Bye-wash Reservoir.
(.) The laying of a suction main from the small pumping dan already constructed to the Pumping Station and of a rising-main from the latter to the gauge basin at the entrance to the Tytam Tunnel.
11. With regard to the Pumping Station, I consider that it will be advisable to establish it somewhat lower down the bay than I at first contemplated. The points which have led to this decision are the improved depth of water available at the altered site and the necessity of keeping the station clear of any place where material to be excavated from the site of the future dam may be deposited. buildings will be arranged in accordance with Mr. CHADWICK's views to accommodate the pumping engines now on order and so as to admit of their future extension when additional pumping plant is required.
The
12. The road will be constructed on the line already submitted to Mr. CHADWICK from a point of junction with the Stanley Road to near the Bye-wash Dam at Tytam. It will ultimately be carried across the top of the future large dam to effect a junction with the road to Shaukiwan.
13. The advisability of carrying it across the dam which I propose to construct at present and so saving a bridge has been fully considered, but the valley conveying the overflow froin the Bye-washi Reservoir is so unfavourable in its configuration for the diversion that practically no saving could be effected in the road itself whilst an increase in the length of the rising mains which will be laid in the road, would be entailed.
14. I propose to lay the rising main with cast iron pipes, 18 inches in diameter, and to make provision in constructing the road for duplicating the main at a future date. The question of the size of the pipes will, however, be submitted to Mr. CHADWICK When the indent for them is sent forward.
15. For the suction main, I propose also to use 18-inch pipes, which will be available for duplicating the rising main when the large reservoir has been con- structed and the suction main from the upper dam is no longer required.