27-11-2012, 05:32 PM
Mumbai's Water Supply
[attachment=41375]
Had the then Mumbai's British administrators not taken seriously an agitation by the island's natives over the drinking water problem in 1845 and subsequent search for water sources even 100km deep into the mainland, Mumbai's citizens, perhaps, would have been as harassed for water as Chennai's people are now. Like Chennai, Mumbai also depended on wells and ponds/lakes for its water supply. Overdrawing of water by ever-increasing population caused depletion of ground water sources and also ingress of seawater in Chennai. The same could have happened to Mumbai, as both these are coastal cities. But, water supply in Mumbai kept rising with newer schemes to meet the increase in demand for the growing population and the city is, comparatively, better off. However, the reasons for water shortages are distribution losses, pilferage, wasteful use etc., causing about 40%-60% loss of water.
Mumbai's Water Sources
From just 32mld (million litres per day) from Vihar Lake in 1860 for Mumbai's then population of only 0.7million, the water supply from various schemes has now reached 2,950mld for the city's 13million people. Table 1 shows how the water supply to the island city was augmented through schemes on six water sources Vihar, Tulsi, Tansa, Modak Sagar, Upper Vaitarna and Bhatsa.
As the population is projected to grow from current 13million to 16million by 2021, future water sources have been identified in Vaitarna River basin and Ulhas River basin that can take the total water supply to 6,382mld by 2021. The plan for Middle Vaitarna is at an advanced stage and a dam will be constructed at a cost of Rs1,250crore to avail 455mld water. This dam will submerge 3,473 hectares of land in Vaitarna basin and people from eight villages will be displaced. Middle Vaitarna, Gargai and Pinjal are gravity sources, whereas the Ulhas river basin sources will need pumping water adding to the cost; 5,108hectares will be submerged, while people of 19 villages will be affected.
Distribution System
Before Independence, Tansa was the major source and these water pipelines run along Bombay-Agra road. After independence, Vaitarna-cum-Tansa project envisaged a tunnel between Vaitarna and Tansa and the water supply to Malabar Hill Reservoir and Bhandarwada Reservoir increased, besides serving the remaining areas directly from the main trunk. The Upper Vaitarna Scheme, in 1973, provided 554mld through tunnels under the Thane Creek. Then came the Bhatsai Scheme which also envisaged construction of pumping, treatment and conveyance at Pise, Panjrapur and Bhandup. Bhatsai water is pumped into Vaitarna mains and brought through tunnels to Bhandup's water treatment-cum-pumping-cum-reservoir complex. From Bhandup's Master Balancing Reservoir I (MBR I) and MBR II at Yewai Hills, water is supplied to the city and suburbs through 17 service reservoirs and 650km transmission mains, 3,000km of distribution mains and 3,200km of service pipes. This, in a nutshell, is how water is conveyed to the city from the sources located at a distance of about 100km, although
distribution is a very complex structure. The cost of production is Rs 6 per kilolitre. This cost is low due to old assets but the cost of water from new Schemes will be much higher.
[attachment=41375]
Had the then Mumbai's British administrators not taken seriously an agitation by the island's natives over the drinking water problem in 1845 and subsequent search for water sources even 100km deep into the mainland, Mumbai's citizens, perhaps, would have been as harassed for water as Chennai's people are now. Like Chennai, Mumbai also depended on wells and ponds/lakes for its water supply. Overdrawing of water by ever-increasing population caused depletion of ground water sources and also ingress of seawater in Chennai. The same could have happened to Mumbai, as both these are coastal cities. But, water supply in Mumbai kept rising with newer schemes to meet the increase in demand for the growing population and the city is, comparatively, better off. However, the reasons for water shortages are distribution losses, pilferage, wasteful use etc., causing about 40%-60% loss of water.
Mumbai's Water Sources
From just 32mld (million litres per day) from Vihar Lake in 1860 for Mumbai's then population of only 0.7million, the water supply from various schemes has now reached 2,950mld for the city's 13million people. Table 1 shows how the water supply to the island city was augmented through schemes on six water sources Vihar, Tulsi, Tansa, Modak Sagar, Upper Vaitarna and Bhatsa.
As the population is projected to grow from current 13million to 16million by 2021, future water sources have been identified in Vaitarna River basin and Ulhas River basin that can take the total water supply to 6,382mld by 2021. The plan for Middle Vaitarna is at an advanced stage and a dam will be constructed at a cost of Rs1,250crore to avail 455mld water. This dam will submerge 3,473 hectares of land in Vaitarna basin and people from eight villages will be displaced. Middle Vaitarna, Gargai and Pinjal are gravity sources, whereas the Ulhas river basin sources will need pumping water adding to the cost; 5,108hectares will be submerged, while people of 19 villages will be affected.
Distribution System
Before Independence, Tansa was the major source and these water pipelines run along Bombay-Agra road. After independence, Vaitarna-cum-Tansa project envisaged a tunnel between Vaitarna and Tansa and the water supply to Malabar Hill Reservoir and Bhandarwada Reservoir increased, besides serving the remaining areas directly from the main trunk. The Upper Vaitarna Scheme, in 1973, provided 554mld through tunnels under the Thane Creek. Then came the Bhatsai Scheme which also envisaged construction of pumping, treatment and conveyance at Pise, Panjrapur and Bhandup. Bhatsai water is pumped into Vaitarna mains and brought through tunnels to Bhandup's water treatment-cum-pumping-cum-reservoir complex. From Bhandup's Master Balancing Reservoir I (MBR I) and MBR II at Yewai Hills, water is supplied to the city and suburbs through 17 service reservoirs and 650km transmission mains, 3,000km of distribution mains and 3,200km of service pipes. This, in a nutshell, is how water is conveyed to the city from the sources located at a distance of about 100km, although
distribution is a very complex structure. The cost of production is Rs 6 per kilolitre. This cost is low due to old assets but the cost of water from new Schemes will be much higher.