1931 Public Works Department Annual Report

Submitted by David on Sat, 11/30/2019 - 11:03

A copy of the original is available at HKGRO: http://sunzi.lib.hku.hk/hkgro/view/a1931/789.pdf



— Q 6 —


31.    New sewers and storm water drains in Hong Kong were constructed to a length of 6,186 feet. Improvements were effected to the main sewer in Aberdeen Valley. Stream courses were trained to a length of 263 feet.

32.    New sewers and storm water drains in Kowloon were constructed to a length of 12,682 feet.


33.    New sewers and storm water drains in New Kowloon were constructed to a length of 15,471 feet.

34.    One side wall and invert North of Camp, Shamshuipo, and Un Long Nullahs and Improvements were completed.


35.    Two steel balance tanks erected at West Point Filters. Reconstructions of Bowen Road Conduit between Tai Tam Tunnel and Stubbs Road completed. 1,120 feet of 18" main laid in Shan Kwong Road. 2,472 feet of 12" main laid in Shaukiwan Road, North Point, and Queen’s Road West. 1,308 feet of 10" main laid in Queen’s Road East. 6,570 feet of 8" main laid in Shaukiwan Road and from Elliot Filters to Kennedy Town Tank. In addition 5,761 feet of 6" diameter main and smaller sizes were laid in Hong Kong to improve distribution.

36.    The Aberdeen Scheme Pipe Line (8,620 lin. yards in length) and the connecting tunnel were completed.

37.    The Aberdeen Upper Dam was completed and opened on December 15th. by H.E. the Governor Sir William Peel, K.C.M.G., K.B.E. The First Section of the East Catchwater and the Outfall Section of the West Catchwater were completed and the 1st Section of the West Catchwater was commenced. Partial demolition of the Lower Aberdeen, or old Paper Works Dam was commenced. The Upper and Lower Pumping Stations and Depot were completed and occupied. The new Rapid Gravity Filter Plant at Elliot, four million gallons per day capacity, was completed and brought into use. The Aberdeen Scheme was brought into use and the water taken into supply on August 1st, one year and nine months after commencement of the works.

38.    In Kowloon the following lengths of mains were laid to improve distribution:—2,616 feet 12", 600 feet 10", 2,091 feet 8", 3,884 feet 6" and 1,906 feet under 6".

39.    The 3" Fanling supply main was duplicated for a length of 6,900 feet. Further trial pits at Shing Mun Gorge Dam Site were sunk for the Consulting Engineer who visited and inspected them early in the year and reported favourably on the site The site was later opened up over a considerable width and one

- Q 7 -

of the Consulting Engineers again inspected and reported favourably. The Hong Kong Public Gardens Service Reservoir, the last item of the 1st Section of the Shing Mun Scheme, was commenced and good progress was made. The Kowloon Byewash Reservoir was completed and brought into use, forming a link between the Shing Mun Scheme and the older works.


40. At Tsat Tsz Mui a reclamation of about 2 1/2 acres was carried out. An area of 1 1/2 acres approximately has been reclaimed for traffic adjoining the ferry pier under construction at Jordan Road. The China Light & Power Co. reclaimed an area of about five acres at To Kwa Wan. The reclamation at Cheung Sha Wan was extended by further dumping of Sanitary department refuse. The total of the area now formed amounts to about twelve acres.


41.    The construction of the pier at Wilmer Street was completed. Construction was commenced on a ferry pier 309 feet in length and 200 feet in width in front of the Fire Station Building between Queen Victoria Street and Jubilee Street. The seaward portion of the pier for 150 feet is constructed in the form of two arms providing a basin for berthing the vehicles ferry.

42.    Adjoining the reclamation at Jordan Road, the work was undertaken of constructing reinforced concrete arms to form a basin for berthing the vehicles ferry on the Kowloon side of the Harbour. The work of constructing the pier at Mong Kok was completed. The pier in structural steel work for Hung Hom Government Store was completed. The work of constructing the pier at Shamshuipo was completed.


43.    The following works were completed during the year: —

Electric light and power installations were fitted to the following buildings:—Victoria Gaol New Printing Shop; Government Stone Quarry, Aberdeen Pumping Stations (Upper and Lower); Married Quarters Lai Chi Kok Prison; To Kwa Wan Sanitary Inspectors Quarters and Bungalow at Tai Po Road. Two latrines and bathhouses and six ferry piers were wired for electric lighting. Twenty one Government buildings in Hong Kong and Kowloon were rewired. The telephone system and fans and lights in certain buildings of the Kowloon-Canton Railway were maintained. A number of telephones were installed at various places. Installation of additional 100 line switchboard was completed at the Kowloon Government Telephone Exchange.


— Q 23 —    P.W.R. Kowloon.

140.    Maintenance of Water Works. A constant supply was maintained throughout the year in all districts.

141.    Water from the new Byewash Dam became available on 16th January, 1931. This dam which forms the connecting link between the Kowloon Reservoir and the Shing Mun Supply has a capacity of 185.50 million gallons and provides a much needed addition to the mainland storage.

142.    Owing to intensive development in practically all districts of Kowloon, the distribution system is becoming inadequate and a big main-laying programme together with the construction of a large service reservoir will shortly have to be undertaken.

143.    The supply during the year was maintained at the necessary pressure by means of connections from the 24" trunk main from the Shing Mun Supply.

144.    The total yield of the Shing Mun River as measured by the Recorder and V. Gauge at the Upper intake was 5,098.45 million gallons as compared with 5,189 million gallons last year. Additions to the Shing Mun supply were obtained from the Needle Hill stream and from pumps below Pineapple Pass. The pumps worked on eighty-six days during the year and delivered 43.47 million gallons equivalent to 505,000 gallons per working day. During the year 2,035.84 million gallons were delivered from the Shing Mun Valley through the Tunnels into the Reception Reservoir, but a large percentage of this quantity could not be stored and ran to waste. The minimum monthly yield was in February when the quantity delivered was 55.50 million gallons. After the completion of the 2nd section of the Paterson Rapid Gravity Filtration Plant in 1932 it will be possible greatly to reduce the waste referred to above.

145.    The total quantity filtered by the existing Paterson Filtration Plant during the year was 1,377.66 million gallons 632.63 million gallons of which were supplied to Hong Kong.

146.    The Shek Li Pui Service Reservoir was completed early in the year and has proved of great benefit for distribution purposes. Incidentally it has increased the mainland storage by eleven million gallons.

147.    The total quantity of water supplied during the year was 1,840.39 million gallons (excluding 104.33 million gallons supplied to Water Boats at Lai Chi Kok) which gives an average daily consumption of 5.04 million gallons or 17.5 gallons per head, per day based on an estimated population of 288,000. Details are given in Table IX.

148.    The quantity of water stored in the impounding reservoirs on 1st January was 463.98 million gallons and a minimum of 240.58 million gallons was reached on 13th April.


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A summary of the works carried out under this vote is given below.



101.    New No. 2 Police Station.—This work was described in paragraph 107 of the Report for 1930 and a further report is given in paragraph 190 of the 1931 report. The work proceeded satisfactorily and was completed on the 2nd May 1932, one day in excess of the Contract time. Certain work additional to the original Contract was executed including the removal of the weighbridge from the Central Police Station Compound to this Station and an increase in the garages temporarily to house the Fire Brigade for Wanchai.

1932 Expenditure .... $108,166.90

Expenditure to 31st Dec., 1932... $372,192.07

102.    Sai Ying Pun—New Market.—.Reference was made to this building in paragraph 191 of the report for 1931. The work proceeded satisfactorily and the market was completed and ready for occupation on the 22nd April.

1932 Expenditure          $113,792.18

Expenditure to 31st Dec., 1932... $251,090.64

103.    Market at Praya East Reclamation.—This work was referred to in paragraph 194 of last year’s Report. The market was satisfactorily completed by the end of May and handed over to the Sanitary Department on 1st June, 1932.

1932 Expenditure                  $16,992.14

Expenditure to 31st Dec., 1932.... $26,942.61

104.    Latrine at Possession Point.—The Contract for the erection of a public trough closet and urinal which amounted to $15,434.20, was let to Messrs. Lam Woo & Co. on 1st March 1932. The work was satisfactorily completed on 30th September, 1932.

Expenditure              .             $10,819.10


General Works.

105.    Roads.—Consequent upon the erection of new buildings, kerbing and channelling operations were executed on sixteen roads, etc. Footpaths were paved and any necessary alterations in levels or alignment affected.

Expenditure                          $48,281.69


- Q 43 — Loan Works.

267. Surrender of the Royal Naval Arsenal Yard and Kellett Island.—An agreement was completed with the Admiralty by which the above properties will be surrendered under certain conditions and upon payment of $2,000,000. A first payment of $500,000 less a proportion to be met from the Praya East Reclamation Fund was made during the year. The balance will be paid during 1932 and 1933.

Expenditure .$263,741.00
268. Traffic Arrangement at Tsim Sha Tsui.—This work, which was referred to in paragraph 232 of last year’s Report, was completed in January.
1931 Expenditure   $3,327.36
Expenditure to 31st Dec., 1931 $11,042.52
269. Additional 100 line Telephone Exchange Switchboard. —This was installed at Kowloon Government Telephone Exchange.
Expenditure $458.41
Aberdeen Valley Water Scheme.
270. 1931 Expenditure   $624,722.35
Expenditure to 31st Dec., 1931...$1,868,983.12
271. Item B-1, Preliminary and Survey Works.—This work was referred to in paragraph 250, Item No. 1 of last year’s Report. A traverse survey 6,000 feet long for the 1st Section of the West Catchwater was put in hand and completed during the year. Other small surveys including one of the site of the Lower Dam was also done.
272. Item 2, Upper Dam.—This work was referred to in paragraph 250 of last year’s Report. Fair progress was made with this work and by October the Dam and subsidiary works were completed and general cleaning up in progress. Impounding in the reservoir for supply purposes commenced in July and water was brought into supply on 1st August when the water stood at forty-two feet below overflow. On 15th December His Excellency Sir William Peel K.C.M.G., K.B.E. performed the opening ceremony at a public function attended by members of the Executive and Legislative Councils. The Dam has a total length of 400 lineal feet at Roadway Level a total depth from roadway to bottom of foundations of 138 feet a maximum depth of water of 103 feet and an effective capacity of 175 million gallons. The overflow is formed on the main section of the dam and consists of sixteen arched bays each twelve feet long. The roadway ten feet wide being carried over it in a series of rein-

Loan Works. — Q 44 —

forced concrete arches. On either side of the back of the dam flood water channels have been formed to divert the flood water into the water cushion fifty feet by twenty-five feet formed at the base. On the front or upstream face of the Dam a valve well has been built outside the normal section in which is situated the 18" dia. stand pipe, 18" dia. draw off pipes and 15" draw off stop valves. Surmounting the Valve Well at road level is a Valve House in which is situated the headstocks and control gear for the 18" draw off penstocks and 15" stop valvees. There are four 18" dia, draw offs at 290, 310, 330 and 350 A.O.D. each controlled by an 18" dia. penstock and a 15" stop valve while the 18" washout 270 A.O.D. is controlled by an 18" dia. penstock and an 18" dia. stop valve. From the bottom of the Stand pipe the supply pipe is laid through the dam in the draw off tunnel and carried over the water cushion by means of a reinforced concrete skewed arch bridge of forty-two feet span. The dam has been built with an inner watertight seal of five to one (1-2-3) fine cement concrete varying in thickness from ten feet at the base to a minimum of five feet at the top. The main face is composed of precast six to one concrete smooth faced blocks in 15" courses with levelled edges the joints after being raked out to a depth of three inches were caulked with neat cement. The backing to the seal to a level of 275 A.O.D. was of six to one (1-2-4) cement concrete with displacers, from 275 A.O.D. to 315 A.O.D. seven to one (1-2-4) cement concrete with displacers, from 315 A.O.D. to 365 A.O.D. eight to one (1-3-5) cement concrete with displacers and from overflow level (365 A.O.D.) to road level twelve to one (1-4-8) cement concrete with displacers. The outer facing of the dam is composed of six to one concrete precast rock faced blocks in 15" courses the lowest special courses and steps to water cushion being cast in situ. The roadway ten feet wide over the dam is surfaced with 2" of granolithic and has a precast reinforced concrete open pillastered balustrading on either side divided into panels to suit the overflow arching. The foundation drainage of the dam discharges into the water cushion through a number of pipes near the washout and the hearting concrete is drained by a series of stoneware pipes with outlets on the overflow face. The dam contains approximately 26,400 cubic yards of cement concrete and 16,000 concrete blocks were used for all purposes. The concrete for the dam was proportioned and mixed by a mechanical plant erected at the South end of the dam and was placed by means of a chuteing apparatus fed from an elevator tower 100 feet high. The concrete blocks were manufactured at a blockyard in Aberdeen close to the old Paper Mills and were transported to the site along with the other materials by means of a cableway 1,200 yards long.
273. Under the Dam Contract the outfall section of the West Catchwater was constructed and the Wanchai Gap Aberdeen Road diverted. The outfall section of the West Catchwater which is 300 lineal yards in length, draining 184 acres has an


Loan Works.    — Q 50 —

290. Item P, Byewash Reservoir.—This work was referred to in paragraph 248 (P) of last year’s Report. Fair progress was made with the works during the earlier part of the year, and by the end of May the dam was brought up to road level. Final cleaning down was completed early in August. Water was impounded from the beginning of the year and brought into supply on January 14th by connecting the 18" dia. draw-off to the existing supply main to the Kowloon Filter Beds. In June the Reservoir was emptied and the original 18" dia supply main from the Kowloon Reservoir 2,100 feet long, was recovered from inside the Reservoir basin during which time the supply to Kowloon Filter Beds was maintained from the Reception Reservoir. The Byewash Reservoir was then allowed to fill and overflowed on 11th August. The existing overflow channel from the Reception Reservoir has been diverted so that it now discharges into the basin of the Byewash Reservoir. The Access Road to the Shing Mun Filtration Plant which was continued beyond the dam as far as the Shing Mun Filters was completed in June. The dam is situated in the Lai Chi Kok Valley about 700 yards downstream of the existing Kowloon Dam and impounds the water which overflows from the latter as well as the overflow from the Reception Reservoir of the Shing Mun Valley Scheme. The Reservoir has a direct catchment area of ninety acres and a nett capacity of 185.5 million gallons. The top water level is 380.00 A.O.D. and at that level the area of the impounded water is approximately fifteen acres. The dam is of gravity section constructed of mass concrete with pre-cast concrete block faces. The up-stream face is vertical except between the levels of 320.00 and 350.00 A.O.D. where it has a batter of one in sixteen while the down-stream face has a general slope of one in 1.492. The height of the roadway over the dam above the lowest foundation level is 143'-6" and 118 feet above the original stream bed. The various mixes of concrete used in the construction of the dam are as follows:—

  • To seal and upstream face 1 cement, 2 sand, 3 broken stone.
  • To backing below 290.00 A.O.D. 1 cement 2 sand 4 broken stone with displacers.
  • To backing between 290.00 & 330.00 A.O.D. 1 cement 2 1/2 sand 4 1/2 broken stone with displacers.
  • To backing between 330.00 & 380.00 A.O.D. 1 cement 3 sand 5 broken stone with displacers.
  • To Reinforced Cement Concrete Arches. 1 cement 2 sand 4 broken stone.
  • To pre-cast Blocks. 1 cement 2 sand 4 broken stone.
  • To dam above 380.00 A.O.D, Lime and cement concrete, with displacers.

The pre-cast blocks forming the up-stream face of the dam are smooth faced with level joints while those on the down stream face have an imitation rock facing with margin drafts.

— Q 51 —    Loan Works

291.    The overflow section of the dam consists of sixteen twelve feet bays, and the ten feet wide roadway, which traverses the dam, is carried over the overflow section by sixteen reinforced concrete arches twelve feet span and two feet rise. The overflow is collected in two flood water channels which discharge into a water cushion fifty feet wide at the toe of the dam and thence over a sill into the original stream bed. A valve well is constructed centrally in the dam and is surmounted by a rectangular Valve House containing the operating gear for the various control valves. There are four 18" dia. draw-off pipes each controlled by an 18" dia. penstock and a 15" dia. Sluice Valve at levels of 300, 320, 340, and 360 A.O.D. and each is connected to an 18" dia. stand pipe. The 18" dia. supply main from the stand pipe crosses the South-east flood water channel on a reinforced concrete skewed arch bridge of 42'-0" span. A total of 29,300 cubic yards of concrete were placed in the works, the total number of blocks made being approximately 14,100 of which 7,200 were rock faced and 6,900 smooth faced.

292.    The contractors for the works were the Hong Kong Excavation Pile Driving and Construction Co. who introduced modern equipment for the construction of the dam. Materials, except stone which was found near the site of the dam, were transported by road to a loading station at the East end of the dam and carried over the valley by overhead cableway to the mixing station. The sand and cement were deposited from the cableway direct into storage bins constructed immediately above a concrete mixer of one cubic yard capacity. The mixed concrete was hoisted inside a steel tower and discharged into a chuting equipment suspended from a cable slung across the valley. The pre-cast facing blocks were cast in gang moulds on a specially prepared concrete floor adjacent to the mixing station, the faces of the rock faced blocks being formed by cast iron moulds.

1931 Expenditure         $217,883.07

Expenditure to 31st    Dec.,    1931    $518,623.89

293.    Item Q, Hong Kong Gardens Service Reservoir.—This work was referred to in paragraph 248 Item (Q) of last year's Report. A Contract for the construction of the Reservoir was signed on the 15th September by Messrs. Yee Lee & Co. for the sum of $189,500.95 and by the end of the year very good progress had been made with the excavation, tipping to banks, piling, concreting of main walls and turfing. The steel work for the reinforced piers and roof arrived from England during December.

1931 Expenditure..     $32,390.38

Expenditure to 31st    Dec.,    1931     $32,601.88



This work was referred to in paragraph 124 of last year's Report. The large embankment at picket 23/00 was con­solidated by means of watering and rolling and the work of bringing it up to level was completed at the beginning of April.

A contract amounting to $17,186.00 was let to Messrs. Sang Lee & Co. in March for strengthening the Conduit. Progress during the year was poor. The Contract which comprised the construction of a new Conduit from the Tai Tam Tunnel Outlet to Stubbs Road, a distance of 2,273 feet, had been completed by the end of the year. The Conduit is designed to meet heavy traffic requirements, but as far as practicable it has been con­structed, in lighter section, clear of the roadway.

1931 Expenditure.............   ................. $22,037.01

Expenditure to 31st December, 1931    $63,830.97

—This work was referred to in paragraph 144 of last year's Report. The progress with the construction of the reinforced concrete portion of the work was unsatisfactory and was not completed -until the middle of April which was five months in excess of the Contract period. The construction of the steel bridge spanning the space between the concrete structure and the shore was commenced on the completion of the above work and completed at the end of the year.

1931 Expenditure                                     $38,597.22

Expenditure to 31st Dec., 1931            $56,957.00

299. This work was referred to in paragraph 252 of last year's Report. The work undertaken comprises the construction of a group of ferry berths and reclamation in front of the Fire Station frontage between Queen Victoria Street and Jubilee Street, Hong Kong, also the construction of a vehicles ferry berth and reclamation on the 'South "side of Jordan Road, Kowloon. The group of piers on the Hong Kong side will accommodate one vehicles ferry vessel and four passenger ferry vessels berthing simultaneously, in addition there will be a timber wharf on the West side of the reclamation and one side of the existing Queen Victoria' Street pier, the latter two berths to accommodate the fire float and craft under the Superintendent of Import and Exports. The reclamation to be carried out in connection with this scheme of berthage will be upwards of one acre in extent. The reclamation under construction in connection with the vehicles ferry berth on the south side of Jordan Road is upwards of two acres in extent and abuts on the western boundary of the Admiralty Oil Depot.