—
714
In addition to the above, a new conduit, gauge basin, service and washout pipes between the filter beds and service reservoir, sand screening pit and eight Venturi meter chambers are included in the contract.
The construction of the new filter bed and of the conduit conveying the unfiltered water to the beds was first undertaken and, at the close of the year, both works were about half completed.
76. Kowloon Waterworks, Gravitation Scheme.-Fair progress was made with the various sections of the work with the exception of the main dam which continued to progress very slowly. Operations were, however, sufficiently advanced to admit of turning into the mains on the 24th March some of the streams intercepted by the catchwater and clearwater channel, thus augmenting the supply to the extent of at least 75,000 gallons per day. The. further progress made during the year enabled water to be impounded in the reservoir and, by the adoption of some temporary expedients, a filtered supply, sufficient for the needs of the whole of the Kowloon Peninsula, was turned on on the 24th December, 1906, thus superseding the original works for the supply of Kowloon, which came into operation on the 24th December, 1895, or exactly 11 years earlier.
(i.) Storage Reservoir. The height of the main dam was increased by 18 feet during the year bringing it to an average height of 418 feet above Ordnance Datum or 30 feet below overflow level. The following are the quantities of material used in its construction during the year :—
Cement Concrete,
Rubble Masonry Facework,
6,600 cubic yards.
400 75
Ashlar
>
"
9,500
feet.
"7
The pipes and valves were fixed in the valve well and culvert during the wet season, thus enabling water to be impounded in the reservoir for the supply of the Peninsula during the dry season.
The excavation for the Byewash Dam and Channel was practically completed in October and a commencement was made, towards the end of the year, with the concrete and masonry work.
(ii) Tunnels, Site for Filter Beds, &c.--This work was completed by the WING ON FIRM in the Summer. The laying of the 18" main for conveying the water from the gauge basin to supply Kowloon was completed on the 24th March rendering available from that date, as already mentioned, the water derived from the Clearwater Channel and from a portion of the Catchwater. The pipes for the 10′′ main connecting the Storage Reservoir with the gauge basin at the head of the 18" main did not arrive until the end of the year, so, to avoid delay in rendering the water stored available, temporary connections were made enabling the water to be passed to the Filter Beds on the 21st December and supplied to Kowloon a few days later.
(iii.) Filter Beds.-A supplementary contract had been entered into in December, 1905, with the WING ON FIRM for the construction of three Filter Beds each of about 800 square yards area. The actual construction of these beds was completed before the end of 1906, except as regards the forming of the necessary connections, the pipes and fittings for which had not arrived from England. Recourse was therefore had to temporary wooden troughs through which the water was conveyed to Filter Bed No. 3 and passed from it into the 18" main, a regular supply of filtered water to Kowloon being thus commenced on the 24th December.
(iv.) Catchwater and Clearwater Channel.—The clearwater channel was completed in January and connections made to the large stream at 1,400 feet on the Catchwater and to the stream taking the water from the Southern portion of the Catchment Area. This water could not however be made available for the supply of Kowloon until March owing to the delay in getting the main laid under the contract for the Tunnel and Filter Beds Site. The Catchwater was completed up to 5,900 feet by the end of the year and work on the remain- ing portion was well advanced. The raising of the Tai Po Road alongside the Reservoir and à bridge across the discharge channel from the Catchwater, which were also included in this contract, were completed in August.