The problem with large-scale solutions India’s states have created climate adaptation strategies that call for big changes in behavior. The southern state of Karnataka, for instance, developed a plan recommending increased use of rainwater harvesting structures, wider adoption of drip and sprinkler irrigation in agriculture, tighter restrictions on borewells, and improved sewage management to prevent water bodies and aquifers from being polluted. But experts say these plans would be incredibly difficult and expensive to implement, and inadequate even if they were realized. India needs to overhaul the way it uses water. The dry parts of the country will have to create jobs in industries other than agriculture, which currently employs nearly half the workforce. Cities will need to build modern networks of water and sewage pipes, treatment facilities, and wetlands, and restrict development and add flood protections along waterways. But one of the most effective ways of dealing with an erratic water supply is to add storage, says Veena Srinivasan, a senior fellow at the Ashoka Trust for Research in Ecology and the Environment. That can mean everything from small-scale, private efforts like capturing rain on rooftops to centralized, large-scale dams, canals, and reservoirs. The federal government generally prefers the latter. The most obvious and ambitious example is known as the Indian River Inter-link, a civil engineering project costing more than 5.5 trillion rupees ($80 billion) that would stitch together more than 60 of the nation’s rivers into a network. The idea is that the government could smooth out imbalances across thousands of miles, sloshing water from a flooded area on one side of the country to a drought-gripped region on the other. The concept dates back to the 19th century, but it’s getting a boost from Prime Minister Narendra Modi, who pushed through approvals for the first phase. Critics say it’s a boondoggle in the making, driven more by the political appeal of a silver-bullet solution than by any scientific evidence that it will work. In a nation as large and spread-out as India, any broadly workable strategy requires better water management at local levels, Srinivasan says. That means capturing and filtering rainwater in tanks; rehabilitating lakes, ponds, and rivers; and using both to recharge aquifers. “You’ve got to rely on groundwater, which means you’ve got to figure out ways to manage it,” she says. Bangalore's sewage miracle On a morning in early March, Vishwanath Srikantaiah leads me on a tour around Jakkur Lake, a bowling-pin-shaped body of water in Bangalore. Srikantaiah, a 55-year-old civil engineer turned water activist, is known as the “Zen Rain Man” of the swelling megacity, in the southwestern state of Karnataka. Standing a willowy 6' 4" (1.93 meters), with a full beard and long, wavy, graying hair, he looks the part. Along the northeastern shore, he steps off the walking path around the lake and onto a thin trail leading into the surrounding wetland, a bright green thicket of cattails, water hyacinth, and alligator grass. About a hundred yards down the trail, he gestures toward a channel at the edge of the grasses, where a stream of burbling water feeds into the lake. “You can see it’s absolutely clear water coming in,” he says. Days earlier it was raw sewage. Most of Bangalore’s water is pumped up from the Cauvery River, around 100 kilometers south of the city. But about 40% of the residents rely on groundwater, largely drawn up from hundreds of thousands of borewells plunging into the ground throughout the city. The growing population has placed enormous strains on that resource both by sucking it up faster than it can be replenished and by polluting the water bodies that recharge it. Srikantaiah helped form Bangalore’s Rainwater Club in 1991 to help people install rooftop rainwater harvesting systems. They’re little more than open pipes that collect water at the ebb of an angled roof and then run it through a filter into a tank. But the water can be stored and consumed or sent down wells to replenish aquifers. Srikantaiah and his wife, Chitra Vishwanath, an architect who focuses on ecological design, later formed a nonprofit that lobbied the city’s utility to set up a water treatment plant at the edge of Jakkur Lake. The growing neighborhood had polluted the lake for years. Part 5 to follow.