1.1. Early Water supply source to Chennai (Madras):
1.2. Development of organised water supply system:
1.3. Beginning of protected water supply system:
1.4. Development of new sources:
1.5. Improvement works carried out during 1946 to 1966:
1.6. Source Augmentation works:
1.7. Additional works carried out during 1968 to 1978:
1.8. Abstraction of Ground water:
2.1. To augment water supply to Chennai with consequential improvement and expansion of the existing water distribution system, a Master Plan was formulated in 1978. This Master Plan identified river Krishna as one of the viable sources for the Chennai Metropolitan Area. CMWSSB implemented the improvement works in a limited way till 1991 depending upon the funds availability.
2.2. Construction of 90 MLD Treatment lant:
In order to supplement the mechanical treatment capacity at Kilpauk Water Works, an additional module of 90 MLD capacity was sanctioned by the Government for Rs.295 lakhs in the year 1983. The works of construction of Filter House, Clarifiers, Chemical House and 9th filtered water underground tank were completed and commissioned on 14th April 1990. With this additional capacity, the total treatment capacity by Mechanical Filters increased to 270 MLD at Kilpauk which helped to treat the water at uniform standards before distribution.
3.1. An agreement was signed jointly by Governments of Maharashtra, Karnataka and Andhra Pradesh on April 14, 1976 to spare 15 thousand million cubic feet (TMC) of Krishna water to Chennai city. Following this, an accord between Andhra Pradesh Government and Tamil Nadu Government was signed on April 18, 1983 for drawing 15 TMC of Krishna water to Chennai City from Sri Sailam Reservoir to be conveyed through Somaseela and Kandaleru Reservoirs and ultimately a net quantity of 12 TMC (after loss of 3 TMC enroute in evaporation and seepage) will reach the Tamil Nadu border.
3.2. Initial works for supplying water under this scheme were completed in 1996 and from September 1996, water is received at Poondi Reservoir from Kandaleru Reservoir in Andhra Pradesh through 152 km. long open canal upto Tamil Nadu Border near Uthukottai. Then, the water is conveyed through 25 km. long open canal to Poondi Reservoir. From Poondi Reservoir, water is transferred to Redhills and Chembarambakkam Lakes through Link/Feeder canals and supplied to city after treatment.
4.1. The Master Plan for water supply to Chennai formulated in 1978, was subsequently updated in 1991 on the following basis:-
4.2. Increase in the storage capacity of the Lakes:
The Public Works Department executed the works for increasing the storage capacity of the Poondi, Redhills and Chembarambakkam Lakes under the Krishna Water Supply Project during 1991-92.
The Chembarambakkam Lake water is being used for the city water supply from the year 2000 during scarcity periods by conveying water to Porur Lake through an open channel and then by reverse pumping to conduit near Redhills for onward transmission to Kilpauk Water Treatment Plant for treatment and supply to the city.
The present capacity of the Lakes is as follows:
|Lake||Capacity (In Mcft.)|
5.1. The Master Plan updated in 1991 was revised in August 1997 based on the updated water requirement and water allocation for each beneficiary as per the actual census figure of 1991. The updated (1996-97) water requirement and water allocation for each beneficiary were assessed as follows:
|Area||Water requirement (in MLD)||Water allocation (in MLD)|
|2001||2021||Krishna Stage I||Krishna Stage II|
|1. Chennai City||710||942||525||760|
|2. Spl. Industries in Manali||170||330||140||300|
|3. Adjacent Urbanised Areas||333||511||130||228|
|4. Distant Urbanised Areas||114||197||32*||69|
* From Local Sources
5.2. As per the Revised Master Plan proposals, Chennai City water distribution system has been divided into 16 Zones. For this, 12 Water distribution stations were newly constructed and improvements to the 11 water distribution systems were completed. Leak detection and rectification works were carried out as water conservation measures by replacing the old and choked up water mains for a length of about 585 km. and 1.95 lakh house service connections were renewed. Transmission mains for a length of 36 km. were laid to convey water to various water distribution stations. The Kilpauk water treatment plant has been refurbished for treating 270 million litres of water daily. Also, bulk meters were fixed in the water treatment plants and water distribution stations.
Geographical Information System (GIS) was developed in a pilot area. Information System Technology Planning (ISTP) was implemented as a pilot project. A detailed study on the potential of Araniar-Kosathalaiyar River Basin for the extraction of ground water has been carried out during 2002-2004 and assessed that 100 mcm per year during normal years and 70 mcm per year during drought years can be extracted from these aquifers. These 16 Water Distribution Zones are provided with a separate water distribution station which is fed by a dedicated transmission main from the treatment plant.
The Veeranam Water Supply Project was implemented as additional source of water to Chennai City. The Project was commissioned in the year 2004 to supply 180 MLD of water to Chennai City by drawing water from Veeranam Lake. This lake receives water from Cauvery River system through Kollidam, Lower Anicut and Vadavar Canal besides rainwater from its own catchment area. The capacity of the lake is 1465 Mcft. The lake water is treated at Vadakuthu Water Treatment Plant by pumping raw water at a distance of 20 km. from Sethiathope to Vadakuthu through 1775 mm dia mild steel pipe. The treated water is then pumped at a distance of 8 km. to Break Pressure Tank at Kadampuliyur through 1750 mm dia mild steel pipe and from there the water is conveyed to a distance of about 200 km. through the mild steel pipe of 1875 mm and 1500 mm dia by gravity to Porur Water Distribution Station near Chennai. From this Distribution Station, water is pumped to a distance of 1.2 km. and distributed to Chennai City through Trunk mains and Water Distribution Stations.
Metrowater also purchased water from the private agricultural wells in the Araniar-Kosathalaiyar Basin to augment the source. The water from the private agricultural wells conveyed through the Well Fields pipeline network to the Chennai City and other consumers. Till Jan 2008. During poor storage in the lakes, the water from these wells may be drawn based on the boards requirements.
To treat the water received from Krishna water source under the Telugu Ganga Project, construction of a 530 MLD water treatment plant at Chembarambakkam near Chennai and transmission line was sanctioned by the Government during August 1996 with an estimated cost of Rs.296.00 crore. Now, the construction of the Plant has been completed by the CMWSS Board. The trial operation of the plant began on 8.4.2007. The plant has been inaugurated on 19.7.2007.
The surapet water treatment plant of 14 mld capacity was taken over from TWAD Board from 01.08.2009 for further Operation and maintenance.
A Desalination plant of 100mld capacity has been commissioned on 31.07.2010 at Kattupalli Village near Minjur. The plant was constructed by DBOOT (Design, Build, Own, Operate & transfer) basis by M/s. Chennai Water Desalination ltd (CWDL) and metro water has entered bulk water purchase arrangements with the firm for 25 years.
Presently the total water treatment capacity for Chennai City is as follows:
|Water Treatment Plant||Capacity (In MLD)|
|Vadakuthu (Veeranam Lake Source) (2004)||180|
|Minjur Desalination Plant||100|
The following is the growth profile in water supply since the formation of the Board in 1978 to July 2010.
|Operational Area||City 176 sq.km.||City + surrounding
areas(176 + 7.88 sq.km.)
|Population||30 Lakh||55 Lakh|
|Water produced (Normal years)||240 MLD||760 MLD|
|Area covered with piped supply||80%||100%|
|Treatment capacity||182 MLD||1,398 MLD|
|Length of water mains||1,250 km.||2,930 km.|
|No. of consumers||1,16,000||4,97,811|
|Distribution Stations||3 No.||16 Nos.|