The Dhaka WASA should develop surface water sources immediately because the ground Water reserve, until now the main source of water supply in the capital, is depleting last and can no longer meet the rapidly growing demand. according Io a regional report.
Il strongly recommended immediate implementation of the proposed Sayedabad surface water treatment project, utilising the waters of river Shltalakhva. but cautioned against pollution caused by industrial wastes in the river
The report by the Asian De velopment Bank (ADB). released recently, was based on a workshop held earlier participated by local consultants of eighi big cities including Bangkok. Beijing. Delhi Ja karta. Karachi. Manila and Seoul to develop strategies and actions for managing water resources in a sustainable
manner
A local firm. Engineering and Planning Consultants Ltd. presenting its paper at the regional workshop on ' Managing Water Resources to Meet Megacity Needs’ stressed the importance of developing management of water resources immediately as "there may I* a serious problem particularly due to over-extraction and increasing pollution.'
WASA records Indicate that liie ground water level in the city has declined at the rate of one metre per year since 1970 and In some places It has gone down to 28 metre below ground level.
"Consequently in recently drilled deep tubeweils. the pump house pipe is needed to be lowered down to 55-60m. Back in 1960 a pump depth of only 20 metres used to be suf ficient," according to the proceedings of the work, which aimed al helping formulate ap
proprlate strategies and actions for managing water re-sources in a sustainable way.
The present sub-soil reserve can meet only 60 per cent of the water demand of the capital.
WASA should embark on a plan to augment its facilities to alleviate critical water supply deficiency in Dhaka, set up a firm base for improvement geared to the ability of consumers and Improve billing arrangements and bring system loss, which is around 50 per cent, within control, the report said.
Highlighting the surface wa ter development potential, the proceeding of the workshop contained in the ADB report said. Both the Shita-lakhya and the Buriganga rivers successfully meet the water quantity and quality requirements. However, increasing pollutant load is anticipated in the Buriganga from industrial discharges."
Pollution risk in the Buriganga is very high due to high river traffic, which causes extensive oil spillage from passing river craft.
It further said, on the basis of a cursory examination, in the Shltalakhya in the upstream of Demra at Ghorashal. two large fertiliser plants were discharging wastes containing significant quantities of organic pollutants including ammonia and arsenic.
"In addition to the above-mentioned upstream pollution sources, there are several other point pollution sources whose discharges may reach the Sayedabad Water Treatment Plant intake proposed at Demra because of tidal effects and the reverse flow generated by the consumptive use of the river water." the report said.
The extent of water quality problems that may arise from the low level of fresh water In the Shltalakhya river should be ascertained and solved as re qulred for the satisfactory op eration of the proposed Sayed abad surface water treatment plant.’ it pointed out.
As regards ground water utilisation It suggested all new wells In the city with a life span of up to 2010 and be yond should be installed with a pump house pipe deep enough to accommodate the present rate of extraction of I 36 million cubic metres per
Dhaka WASA provides over I 40 lakh water connections in the city an.I Is able to supply 74 crore litres of water per day — only about half the total demand.