When it comes to mass diversion of water, we are geoengineering already:
What few are aware of is that the water is no longer the Shipra’s. Urbanisation, rising demand and two years of severe drought have shrivelled the sacred river. Its natural state at this time of year, before the monsoon, would be a dismal sequence of puddles dirtied by industrial and human waste. But the government of Madhya Pradesh, determined to preserve the pilgrimage, has built a massive pipeline diverting into the Shipra the abundant waters of the Narmada river, which spills westward into the Arabian Sea. Giant pumps are sucking some 5,000 litres a second from a canal fed by the Narmada, lifting it by 350 metres and carrying it nearly 50 kilometres to pour into the Shipra’s headwaters. To ensure clean water for the festival, the Shipra’s smaller tributaries have been blocked or diverted, and purifying ozone is being injected into the reconstituted waters in Ujjain itself.