Q 18
The maximum quantity in storage was 2,842.71 million gallons on 1st January 1938.
The quantity in storage at the end of the year was 1,860.69 million gallons.
Measures to remedy the defects in the Pineapple Pass Dam, referred to in last year's Report, were carried out under the direction of the Consulting Engineers, who were represented locally by Mr. G. B. Gifford Hull, late Resident Engineer in charge of the Jubilee Reservoir construction. The work consisted principally of removing the sand wedge and substituting approximately 4,405 cubic yards of cement concrete. Despite a maximum downstream movement in the core wall of 8 inches, only hair cracks were discovered on its downstream face. These were caulked and patched with bitumen. The granite pitching, which had subsided on the upstream face and bulged on the downstream face, was relaid where necessary. The work was completed in August, but as the highest water level reached was 594.5 A.O.D. (30-6" below overflow level) in October, no opinion on its efficacy can yet be stated. Leakage through the dam on 1st January, when the water level was 606.5 A.O.D. was 3,000 gallons per hour, and reached a minimum of 500 gallons per hour in July when the water level was 559.0 A.O.D. At the end of the year, with a water level of 580.0 A.O.D. the leakage was 700 gallons per hour.
Leakage from the Yaumati service reservoir having increased considerably, the reservoir was emptied and thoroughly examined. Settlement and cracking of the invert in the north-east corner was discovered, whilst slight wall movement had also occurred. These were repaired at comparatively small expense, and leakage was reduced from 118,000 to 1,625 gallons per day. Observations for further movement are being continued. The western section of the reservoir is in good condition and showed no leakage on a three-day test.
4,122.75 million gallons were delivered into the reception reservoir from the Jubilee reservoir and Smuggler's Pass intake. There was no appreciable loss by overflow, as the Byewash reservoir only reached sill level for a few hours on 22nd March following a heavy thunderstorm.
A total of 5,270.23 million gallons was filtered, 1,378.30 being filtered by the slow sand beds, and the remaining 3,891.94 million gallons by the Paterson rapid gravity plant at Shek Li Pui. Of the latter quantity, 1,691.26 million gallons were supplied to Hong Kong.
The total quantity of water supplied to Kowloon was 3,463.72 million gallons (exclusive of 112.76 million gallons supplied to water boats at Lai Chi Kok) which gives an average daily consumption of 9.46 million gallons or 18.9 gallons per head per day based on an estimated population of 500,000. Details are given in Table XVI.
Particulars of the quantity of water supplied by meters are given in Table XVI, the total amount being 2,429.15 million gallons. 70.1% of the total consumption was, therefore, accounted for by meters, compared with 65% in 1937. After making allowance for unmetered supplies through public standpipes, cleaning filter beds, mains, and services, fires, etc., it is estimated that 78.4% of the total consumption was accounted for. The balance is mainly due to losses in the distribution system.
Samples of water were examined by the Government Bacteriologist with the following results:—
RAW WATER
Total number of samples examined 24 Number showing B.C.C. absent in 10 C.C. 2 (8.3%) Number showing B.C.C. present in 10 C.C. or less 22 (91.7%)FILTERED WATER--UNCHLORINATED
Total number of samples examined 24 Number showing B.C.C. absent in 10 C.C. 22 (91.7%) Number showing B.C.C. present in 10 C.C. or less... 2 (8.3%)Q 18
The maximum quantity in storage was 2,842.71 million gallons on 1st January 1938.
The quantity in storage at the end of the year was 1,860.69 million gallons.
Measures to remedy the defects in the Pineapple Pass Dam, referred to in last year's Report, were carried out under the direction of the Consulting Engineers, who were represented locally by Mr. G. B. Gifford Hull, late Resident Engineer in charge of the Jubilee Reservoir construction. The work consisted principally of removing the sand wedge and substituting approximately 4,405 cubic yards of cement concrete. Despite a maximum down stream movement in the core wall of 8 inches, only hair cracks were discovered on its down stream face. These were cauiked and patched with bitumen. The granite pitching, which had subsided on the upstream face and bulged on the down stream face, was relaid where necessary. The work was completed in August, but as the highest water level reached was 594.5 A.O.D. (30-6" below overflow level) in October, no opinion on its efficacy can yet be stated. Leakage through the dam on 1st January, when the water level was 606.5 A.O.D. was 3,000 gallons per hour, and reached a minimum of 500 gallons per hour in July when the water level was 559.0 A.O.D. At the end of the year, with a water level of 580.0 A.O.D. the leakage was 700 gallons per hour.
Leakage from the Yaumati service reservoir having increased considerably, the reservoir was emptied and thoroughly examined. Settlement and cracking of the invert in the north east corner was discovered, whilst slight wall movement had also occured. These were repaired at comparatively small expense, and leakage was reduced from 118,000 to 1,625 gallons per day. Observations for further movement are being continued. The western section of the reservoir is in good condition and shewed no leakage on a three days test.
4,122.75 million gallons were delivered into the reception reservoir from the Jubilee reservoir and Smuggler's Pass intake. There was no appreciable loss by overflow, as the Byewash reservoir only reached sill level for a few hours on 22nd March following a heavy thunderstorm.
A total of 5,270.23 million gallons was filtered, 1,378.30 being filtered by the slow sand beds, and the remaining 3,891.94 million gallons by the Paterson rapid gravity plant at Shek Li Pui. Of the latter quantity 1,691.26 million gallons were supplied to Hong Kong.
The total quantity of water supplied to Kowloon was 3,463.72 million gallons (exclusive of 112.76 million gallons supplied to water boats at Lai Chi Kok) which gives an average daily consumption of 9.46 million gallons or 18.9 gallons per head per day based on an estimated population of 500,000. Details are given in Table
XVI.
Particulars of the quantity of water supplied by meters are given in Table XVI, the total amount being 2,429.15 million gallons. 70.1% of the total consumption was, therefore, accounted for by meters, compared with 65% in 1937. After making allowance for unmetered supplies through public stand pipes, cleaning filter beds, mains and services, fires, etc., it is estimated that 78.4% of the total consumption was accounted for. The balance is mainly due to losses in the distribution system.
Samples of water were examined by the Government Bacteriologist with the following results :—
RAW WATER.
Total number of samples examined
Number shewing B.C.C. absent in 10 C.C.
Number shewing B.C.C. present in 10 C.C. or less
FILTERED WATER--UNCHLORINATED.
Total number of samples examined
Number shewing B.C.C. absent in 10 C.C.
Number shewing B.C.C. present in 10 C.C. or less...
24
2 ( 8.3%) 22 (91.7%)
24
22 (91.7%) 2 (8.3%)
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