Sessional_Paper_1896 — Page 262

(17)

259

Average supply per diem

1,175,000,000

365

3,200,000 gallons, say, storage required=3,200,000 × 242 less the yield of the catchment areas during the months of September to April inclusive (774,000,000 -342,000,000) viz., 432,000,000 gallons. The storage capacity of the reservoirs at Pokfoolum and Taitam on the completion of the works now in hand will amount to 458,000,000 gallons and will therefore be sufficient to secure a constant water supply at the rate of 3,200,000 gallons per diem.

PARTICULARS OF PROPOSED WORKS TO MEET PRESENT REQUIREMENTS.

134. Proposed Catchwater Taitam Valley.-The catchwater contouring the hillside on the west of the Taitam Valley to be constructed of lime concrete rendered in cement laid at a uniform gradient of 1 in 100 and to have a maximum discharging capacity of 2,000,000 gallons per hour.

It will be necessary to convey the water intercepted by this catchwater across the ravine imme- diately south of the present Taitam reservoir by cast iron pipes 14 inches in diameter.

This work is shown on drawing No. 7 and the estimated cost is $40,000.

135. Proposed Catchwater Reservoir near Wongneichong Gap.-The catchwater coutouring the hillside on the south of Wongneichong Gap shown on drawing No. 7 to be of similar construction to one above described and to have a maximum discharging capacity of 1,000,000 gallons per hour. This catchwater will discharge into a reservoir to be constructed near Wongneichong Gap as shown on drawing No. 13.

From this reservoir the water will be conveyed by a cast iron main 5 inches in diameter to the Taitam conduit.

The estimated cost of these works is $83,000.

136. Proposed Filter Beds.-Additional provision for the filtration of 1,000,000 gallons of water per diem is proposed to be provided by the construction of filter beds on the hillside below the Bowen Road as shown on drawing No. 1.

These filter beds are three in number and have a combined area of 1,700 square yards, in con- nection with them a covered service reservoir should be constructed having a capacity of 600,000 gallous.

A cast iron main will connect this reservoir with the existing distribution system and service reservoir at Wanchai now in course of construction.

The estimated cost of these works is $68,000.

Should a supply of water be required above the Bowen Road, I would remark that the project for the construction of filter beds immediately below Bowen Road furnishes facilities for actuating a small hydraulic motor.

137. Proposed Reservoir at the Peak.-A suitable site for the constructions of a covered service reservoir of a capacity of 400,000 gallons exists immediately east of "The Eyrie."

This reservoir would be 16 feet in depth with a top water level of 1,751 feet above Ordnance Datum.

Estimated cost $20,000.

138. Estimated cost of works immediately required.-The following tabular statement gives the estimated cost of works immediately required.

Description of Work.

Improvements Pokfoolum Conduit,

New Mains in the City and Repairs to No. 2 Tank,

Catchwater West of Taitam Valley,..

Reservoir and Catchwater Wongneichong Gap,........

Filter Beds and Service Reservoir,

Service Reservoir Peak,

Total,.....

Amount.

10,000

39,000

40,000

83,000

68,000

20,000

260,000

139. As it is of the utmost importance both on sanitary and general grounds that no time should be lost in providing the City and Hill District with an adequate and constant water supply, I would urge the necessity of at once taking steps to carry out the foregoing works.