11.10
of undersized or defective mains and general distribution improvement continued. 61 miles of mains were laid during the year. Details are given in Appendix CC.
Systematic waste detection continued throughout the year. Quarterly checks were carried out in 304 fresh water areas and annual checks in the 65 salt water areas.
A number of major leaks were discovered and repaired, resulting in an estimated daily saving of more than four million gallons of water. A report on the operation of the Waste Detection Unit (1968 - 1973) was completed.
House Service Sub-Division
11.11
The number of additional meters installed was 55,823, a decrease of 20% on the number installed during 1972/73.
SUPPLY DIVISION
Chief Engineer: NG Lin-hing, B.Sc.(Calif.), D.I.C., C.Eng., M.I.C.E., M.I.Struct.E., M.I.W.E.
General
11.12
The Division comprises a Headworks Sub-Division, responsible for the maintenance and operation of storage reservoirs, intakes, filter stations, trunk mains and service reservoirs, and an Operation Sub-Division, responsible for monitoring pumping stations, treatment works, service reservoirs and other facilities, for the collection and processing of hydrological data for design and record purposes, and for the development of rules for the operation of the multi-reservoir system.
11.13
The Plover Cove Reservoir filled to its newly increased capacity of 50,533 million gallons in September 1973 as a result of heavy summer rainstorms.
11.14
Details of rainfall, storage and consumption are shown in Appendix CC. Rainfall was 42% above average and yield, consumption and peak demand respectively increased by 22%, 7.59% and 9.45% over the previous year.
Headworks Sub-Division
11.15
Tunnel gates installed at the portals at either end of the tunnel linking Plover Cove and Tai Po Tau and that at the junction of the tunnel and the Tau Pass Culvert were tested. Draw-off from Plover Cove Reservoir was resumed on 21st April 1973. The tunnel gate at the Tai Po Tau end was shut during the period from 30th August to 10th December 1973 when the water level at Plover Cove was above 36 ft. A.P.D. to prevent loss of water into the Lam Chuen River at Tai Po.
11.16
During the period (10th August to 1st October 1973) when there was no delivery of Chinese water, modifications to the Muk Wu Balance Tank were carried out in conjunction with the Mechanical Division to improve control and reduce head loss. A 24-hour shut-down of the supply of Chinese water was required for blanking off a badly leaking 36 in. diameter pipe in River Indus.
11.17 was missing, however, the original text stopped at 11.16, hence no further action is required.