XN000022-1984-12-02 — Page 2

SUNDAY, DECEMBER 2, 1984

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FIRST STEP TO TAP WATER RESOURCES

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EVERY DROP OF WATER COLLECTED IN HONG KONG FOR DRINKING PURPOSES IS OWED IN PART TO THE HYDROLOGICAL UNIT OF THE WATER SUPPLIES DEPARTMENT.

HYDROLOGY IS A SCIENCE DEALING WITH THE MOVEMENT, OCCURRENCE AND DISTRIBUTION OF WATER ON AND BENEATH THE LAND SURFACE.

+ IN THE PLANNING OF WATER RESOURCES DEVELOPMENT, IT IS NECESSARY TO COLLECT HYDROLOGICAL DATA ON THE POTENTIAL CATCHMENT AREAS,+ SAID MR WONG SHIU-MING, A. HYDROLOGIST IN CHARGE OF THE UNIT.

+THEN, ON THE BASIS OF CIVIL ENGINEERING AND HYDROLOGICAL STUDIES, AS WELL AS ECONOMIC ANALYSIS, RESERVOIRS ARE CONSTRUCTED TO STORE RAW WATER COLLECTED FROM VARIOUS CATCHMENT AREAS.

+THE 'RAW WATER', AFTER PASSING THROUGH THE TREATMENT WORKS PROCESS, IS STORED IN SERVICE RESERVOIRS AND EVENTUALLY DISTRIBUTED TO CONSUMERS.+

THE HYDROLOGICAL UNIT, THOUGH LOW-PROFILED, THUS PERFORMS THE INITIAL AND ESSENTIAL FUNCTIONS IN WATER RESOURCES PLANNING.

IT ANALYSES DATA ON RAINFALL, RUNOFF, GROUND WATER LEVEL AND SEDIMENTS COLLECTED THROUGH A NETWORK OF SOME 60 HYDROLOGICAL STATIONS AND 120 RAINFALL STATIONS DISTRIBUTED IN VARIOUS CATCHMENT AREAS.

THE UNIT ALSO CONDUCTS HYDROLOGICAL STUDIES ON PARTICULAR NEEDS OF THE WATER SUPPLIES DEPARTMENT BASED ON THE COLLECTED DATA.

THESE STUDIES COVER, FOR INSTANCE, THE ESTIMATED YIELDS OF EXISTING AND POTENTIAL RESERVOIRS AND CATCHMENTS, AS WELL AS THE RELIABILITY AND ADEQUACY OF THE EXISTING SYSTEMS IN SPECIAL CIRCUMSTANCES, SAID MR WONG.

+THE TOTAL TAPPED CATCHMENT AREAS IN HONG KONG COMPRISE ONE-THIRD OF ITS LAND AREA. A SMALL PORTION OF CATCHMENTS HAVE NOT YET BEEN EXPLOITED ON ECONOMICAL GROUNDS AS WE NOW HAVE ADEQUATE SUPPLEMENTARY SUPPLY FROM CHINA,+ HE SAID.

THESE UNTAPPED CATCHMENTS INCLUDE AREAS ON LANTAO ISLAND AND

IN THE NORTH-WESTERN NEW TERRITORIES.

THE WATER SUPPLIES DEPARTMENT HAS ONLY CARRIED OUT LIMITED STUDIES ON THE USE OF GROUND WATER RESOURCES.

AMR WONG