Water supply in Karachi.
The existing water supply network in Karachi is over 100 years old and has become outdated and defective. Most of the mains have outlived their useful life and require renovation and replacement.
The water demand of this thickly populated city is 492 million gallons daily, while the supply of water is limited to 355 (if nothing goes wrong). It shows a deficiency of water upto 90 MGD. This deficiency is likely to increase to 468 MGD by the year 2000, when the demand would be 820 MGD. The on-coming projects will however, take care of the part of the demand for all uses, thereby leaving a gap of 268 MGD between supply and demand for which new proposals will have to be drawn up.
Losses in water supply through leakage are 30 per cent. If this leakage is controlled, and 30 per cent is saved, it is sufficient enough to meet the water requirement of Karachi.
Karachi water and sewerage Board is taking certain
necessary actions to overcome this problem. Such as:
Scientific study has been initiated for Leak Detection
and Repair techniques under UNDP assistance through
A Leak Detection and Repair Cell has been created
and over 2000 leakages repaired so far.
21 km Rehabilitation of Trunk Mains are near to completion
under IDA credit 1374 - Pak, to save losses in
the distribution system.
A Consumer Education Cell has also been established
to educate people to minimise wastage.
Presently, there is a deficiency of water both in residential
areas and industries, due to which the sanitary
conditions in the city are deteriorating and industrial
production is badly suffering. Sufficient data on water
consumption in different areas of the city is not available
which is essential to analyse the existing situation
and undertake planning for the future. Water consumption
surveys are required to be conducted regularly
as part of the water supply service. Karachi water
supply system is grossly deficient one in many respects.
The transmission mains and distribution system is old
and inadequate to distribute the water equitably as
many areas cannot be fed through the network and
have to be served through tankers at all times.
Frequent power breakdowns occur, causing disruption
both in bulk supply and area distribution.
The system is complex and highly vulnerable. Even
minor setbacks disrupt the supply to many areas and
major breakdowns paralyse the whole system.
The main bulk transmission system (syphon 19/20,
Hub canal/Kinjhar Guffo canal) is also very vulnerable.
There are substantial leakages in the system (estimate
to be 30%)
A large portion of the quantity of water supplied to the consumers in Karachi turns into sewerage. Presently, about 200 MGD of sewerage waste is being generated in the city but treatment capacity is limited to 45 MGD (20%) only.
With the increase in water supply, the sewage generation is expected to increase to 392 MGD by the year 2000. Due to the lack of the quality control in the manufacture of pipes and poor construction of sewers, the resulting sewerage system is not built up to the standard. This causes problems in operation and maintenance of the sewerage system.
A nominal quantity of sewerage is treated through water treatment plants, constructed at Gharo 1, Gharo 2, COD Hills, Pipri and North East Karachi.
All plants treat water derived from the River Indus. The remaining resources from Dumlotee and from the Hub are disinfected by chlorination alone.
Untreated sewage flows increasing continuously with the increase in water supply. Large amount of sewage flows into the adequate existing system. The sewers get surcharges and manholes overflow very frequently, causing unsanitary conditions in the city.
Missing and broken manhole covers on roads cause not only serious accidents and are danger to life specially during monsoon rainfalls but a source of environmental pollution and other health hazards.
Sewer lines are laid without allowing proper right-of-way and clearance for other utilities e.g. water lines, gas, and power lines etc. This often result in cross-connections and infiltration of sewage into water mains which causes contamination of water resulting in spread of diseases. Most of the pipelines are cracked. Because there is no twenty-four-hour supply of water to different areas of the city, the infiltrated sewerage water take the opportunity to enter the water pipelines through the cracks during the break hour. When water supply is resumed after the scheduled break the already deposited sewerage water began to run with the flow of normal water. It is not easy to check the cracks of underground laid pipelines. KWSB arrange areas. These samples are examined in the scientific laboratories. And if signs of pollution or bacterial elements are found, remedial actions are taken immediately.
All the waste water generated in the city brought to Mauripur Salt beds and Korangi for treatment in oxidation ponds.
Untreated sewage discharge into the sea affecting marine life. Its also causing coastal pollution and health hazard.
Uncontrolled discharge of industrial and trade wastes containing toxic chemicals and heavy metals and other non-degradable elements also cause serious pollution problems in the environment. Thus if industries discharge their waste-water into the receiving sewer or stream, they are required to treat their waste water to the required standards before discharge. Unauthorised connections from industries discharging large amounts of toxic wastes into the sewerage system may cause damage to sewers and treatment plants.
One time use of water industries and specially for non-potable purposes, such as cooling in steel industries, tanneries, etc. is to be avoided. This is required to economise drinking water supply. Industries may be encouraged to use their waste water to the maximum within the industry to cause consequent reduction in consumption of drinking water.
Gutter water is not advisable for gardening and other plantation of domestic level. Because it carries certain poisonous elements in it. If vegetables, fruits or other crops irrigated by gutter water are used, they will leave harmful effects on the user's health. If the waste water is to be used for irrigation purposes then international standards for affluent treatment have to be followed.
Underground water is brackish and unfit for human consumption. There is no other source except the River Indus to meet water supply needs of Karachi. In case the allocation of additional water supply from Indus is not ensured, Karachi will be subjected to water famine, which may give rise to "Water Riots" of unimaginable magnitude.
Besides, development activities, trade and industrial growth will be seriously hampered. Proper provision of water supply service in Katchi Abadis will not be feasible.
Therefore, it is imperative to stop the population migration from all over the country to Karachi.
There are about 23 different local agencies, responsible for operating the sewage collection service in the city. They operate different levels of service. There must be a coordination between all these agencies with respect to collection and disposal of sewage from different areas to the treatment plants.
It is advisable that in all sewerage schemes affluent utilisation should be an essential part of the scheme. Beside irrigation, other uses such as fish culture etc., should also be explored.
In all new township schemes all waste water should be treated and affluent utilisation with the scheme for irrigation of parks, playgrounds and road plantation as far as possible.
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|Title Annotation:||need to update outdated and defective water supply network in Karachi, Pakistan|
|Date:||Jun 1, 1991|
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