DELHI'S future -to mix metaphors -is in the hands of three dams. But of Renuka, Kishau and Tehri, only the last is under construction; it should supply the city with 675 million litres daily (mld) feeding the proposed 630 mld treatment plant at Shahdara. But next century.

The Tehri Hydel Development Corporation project will cost Rs 5,583 crore, but Delhi has paid up only Rs 4 crore of its Rs 184.78 crore share. The original plan was For Tehri to crank out supply by 1997. "A minimum of four years will be needed for the construction of the carrier, system from Murad Nagar to the site of the treatment plant," says a Delhi Water Supply and Sewage Disposal Undertaking (DWSSDU) spokesperson.

The Renuka, dam on the, Giri - a tributary of the Yamuna in Himachal Pradesh - is a multi-purpose protect that will supply a dedicated 1,237 mld water from its 456.74 billion litre storage, says T S Bateeja, director, Central Water Commission. Delhi's pro rato share is Rs 715 cro're, and, it has already paid 1.45 crore to the Himachal Pradesh State Electricity Board. "An additional Rs 1,200 crore will be needed for an independent carrier system,"says,,the DWSSDU spokesperson.

The dam's construction will take nine years, but gaping holes in the study might trip it up - among them, the project's environmental cost. Government records show that Renuka will submerge 1,210 ha in Himachal Pradesh, with forests, a major portion.

The Kishau dam, still "under contemplation", will be on the river Tons, a tributary of the Yamuna on the Himachal Pradesh, Uttar Pradesh border. CWC officials say that there are two plans: "It can be built to a height of 186 m with flood control," says Bateeja, "or to 176M without flood control capacity or idle storage." The latter, at Rs 380 crore, would cost about half the former.

Government officials beam at the mere mention of the dams. Says K S Rana, CWC chief engineer, river management, "With the completion of these projects, Delhi's water problem will be overcome." Enviromnentalists, however, are remarkably less blustery. Nalini Jayal of the Indian National Trust for Art and Cultural Heritage, which has conducted several studies on the Tehri dam, calls it "a complete sham". Let alone supplying water, to Delhi, "the, dam will run short of water to meet even its own power generation requirements".

Environmentalists say that the total peak water availability of 4,950 mld is grossly overstated. Private tests put the flow at the dam site at as low as 40 cusecs in tbe lean period. Jayal also points out that the dam would. affect about 100,000 people, but the government's rehabilitation package is watery.