In the earliest times Calcutta had been dependent for its water supply on the river and on its tanks and wells. The Great Tank (Dalhousie Square, Lal Dighi at BBD Bag) was deepened and extended in 1709, to ensure a good supply of sweet water for the garrison of old Fort Williams and British Calcutta grew up near its banks.
Between 1805 and 1836, the excavation of large tanks in Cornwallis Square, College Square, Wellington Square and Wellesley Square of Mirzapore and Soortibagan Tanks and several tanks in Short's Bazaar, proved an inestimable boon to Calcutta.
In 1820 a small pumping plant was set up at Chandpal Ghat for lifting river water into open masonry aqueducts, which distributed the water by gravitation over a small portion of the town - Tallah, Chowringhee, Park Street, part of Chitpore Road, Lall Bazaar, Bow Bazaar, etc. M/s. Jessop and Co. worked the engine by contract at Rs 400 a month, running it seven hours a day for eight months in the year. River water, drawn at the ebb and preferably about the tenth day of the moon, was most generally used by the Hindu inhabitants, except those who lived at a distance from the Ganges.
River Water for Drinking
From October to March the river water was said to be wholesome for drinking and culinary purposes; from April until the break of the rains it was saline; in autumn the water was turbid, and it was customary to clarify it by the use of alum or muslin strainers. Some people collected river water in February, and stored it in jars until the rains, the more wealthy often brought water from Hughli or Khulna. Europeans often used rain water, which they stored in common Pegu jars.
Through Act II of 1848, the first explicit recognition by the legislature of the need of supply of pure and whole some water was made.
First analysis of River water leading to selection of Pulta
Between December 1861 and January 1863 Dr. MacNamara was deputed to carry out an elaborate set of analyses of the Hughli water. The water was taken manually from the centre of the stream at 6 feet below the surface and from three stations, namely, from opposite Cossipore, Pulta Ghat and Chinsurah. The analyst reported that water drawn either at Pulta or Chinsurah was comparatively pure and after settling and filtration would afford a pure and wholesome supply, though he personally favoured a scheme for turning the Maidan into a catchments area and source of supply. Mr. W. Clark, Secretary submitted a full report in 1865 on the Pulta Scheme. The works at Pulta water works started in 1868 on about 482 Acre land under Dr. Macnamara, Mr Clark Dr. B.N. De, Mr S.C. Mitra etc.
Pulta Water Works (Filtered)
The works were designed to supply 6,000,000 gallons of filtered water per day to a population to a estimated at 400,000 persons. The water from the Pulta river side to Tala Tank was made through 42 inch cast iron pipe. At Tala another pumping plant delivered the water partly to consumers and partly to another underground reservoir at Welington Square. Another pumping station was built at Welington Square. The total thickness of filter bed varied from 3ft 10 inches to 4 ft 4 inches. The pipeline from Pulta to Tala was drawn with a fall of about 11.5 inches per mile. 3nos. 50 HP enginees at the river bank of Pulta were used to lift into large massonary tanks. The reservoir at Tala and Welington Square had capacity of 1 ML 6.25 MLG. The total cost was Rs. 66 Lakhs.
In 1870 all principal streets and lanes (385 nos.) had been piped, total length 111.75 miles. Over 500 stand posts were erected as made accessible to the public. Towards the end of 1870 daily consumption was 4.5 MLG. In 1870 a 3rd engine was ordered for the Welington Square pumping station. Subsequently a new pumping station was built at Bhabanipore and other places.
Since the early days the water supply system has under gone many changes. The famous overhead Tala tank was built 1911.
Early days of water supply - few interesting figures : {source : Municipal Calcutta by S.W. Goode, 1916}
At the end of 1871, 2316 houses out of 16,000 in Calcutta had been connected with the mains, the number of Filtered Water House connection at the end of 1914-15 was 33, 221.
It will be interesting to mention the water charges at early days as follows :
Per 1000 Gallons
1)
Cossipore-Chitpore Municipality
:
4 annas
2)
South Dum Dum Municipality
:
8 annas
3)
Garden Reach Municipality
:
4 annas
4)
Manicktollah Municipality
:
4 annas
5)
South Suburban Municipality
:
4 annas
6)
Tollygunge Municipality
:
4 annas
7)
Barrackpore Cantonment
:
4 annas
8)
Dum Dum Cantonment
:
8 annas
Some Waterworks Statistics.—The following Table illustrates the great extensions made on the original system
112 miles
184 miles
310 miles
315 miles
324 miles
354 miles
363 miles
25 miles
64 miles
75 miles
155 miles
220 miles
246 miles
270 miles
470
990
1954
1997
2031
2467
…….
511
2,505
2,911
5,680
8,238
10,288
………
Thus, potable water supply to the city of Kolkata started from Palta in 1869 with the installation of a 6 million gallon per day (mgd) or 27 million litre per day (mld) capacity slow sand filteration unit at Palta. To cope with the increasing demand for potable water, the capacity of the water treatment plant at Palta was augmented in stages and brought to 46 mgd (209 mld) by 1911. In 1936 some new slow sand filteration units were added, but from 1936 to 1945 no further development works to increase the quantum of potable water supply were taken up. In the early fifties the filtered water supply increased from about 60 mgd (273 mld) to about 68 mgd (309 mld). Per capita supply however decreased from about 52 gpcd (236 lpcd) to about 27 gped (123 lpcd). In addition, there was unfiltered water supply and ground water supply from tubewells.
In the early 19th century the Howrah City used to get water from a 4 mgd. (18 mld) water treatment plant located at Serampore, about 19 km. north of Howrah City. For the other Municipal Towns water came much later. With phenomenal growth of population after partition of Bengal and independence of India, water supply situation reached alarming proportions.
Current Situation :
The water supply in KMA is dependent on treated surface water from the river hooghly and ground sources through Deep Tube Wells (DTW) and Hand Tube Wells (HTW). A considerable quantity of water for KMA is available from several water treatment plants with total rated capacity of slightly more than 1400 MLD, being located at different parts of KMA.
With regard to the ground water sources within KMA, several studies indicates that as a result of over withdrawal of ground water, piezometric levels dropped significantly alongwith ground subsidence. Such studies have also indicated that new challenges of threat are being faced in the form of Arsenic contamination of ground water, that has been knocking at the door forcing to adopt conceptual change in design parameters to ensure supply of safe water, to the community.
Service Districts :
Due to change in the development trend and addition of substantial area in KMA, the area is now proposed to be served by six re-delineated Water Supply Service Districts.
New water works:
New water works have been suggested for the municipalities including their immediate fringe areas under panchayats bodies consisting of both rural and non-municipal urban areas.
Augmentation :
The augmentation of Water Supply is taken up with the same objective for municipalities and their adjoining non-municipal urban and rural areas.
Tariff and Financial Reforms :
Tariff rationalization is an essential pre-requisite to financial viability. User charges in KMA happen to be the most important mechanism of cost recovery. Water supply also qualifies for imposition of user charges. The users are also slowly being accustomed to think of paying user charges for the services the government is providing. There has been talk of water pricing which has been implemented in a few states and is now being seriously considered obligatory under legislation.
Conservation Measures :
In view of the fast growing population, urbanisation and industrialisation and diminishing water resource, it is necessary to conserve available water and harvest rain water to the maximum extent possible, through:
» Leak detection and rectification works
» Rain water harvesting, through in-situ tanks, check dams etc.
» Controlling indiscriminate extraction of ground wate
» Recharging of aquifer.
» Meters to be installed along trunk mains and for bulk consumers
