Planning a pond

With some idea on all the above, I contacted DHAN for professional help in the actual engineering design of pointReturn’s pilot pond. DHAN has several years of experience in implementing small and large watershed development programmes in several parts of south India. They are a trusted partner in the government’s national watershed development programme. There would be several organisations in your area you could consult. Various state governments now actively encourage private initiatives and their engineers can give valuable advise.

I called Ms Raghini Mohan, a senior DHAN executive and now a friend. She graciously arranged for a team of tank experts to visit the pointReturn site on June 29. At 10.30am that morning I picked up 6 of them from their office at Chengalpattu and drove to pointReturn. Friends Sangeetha, Sumathi and Ananth also joined us for the day. Once at the site they walked all over studying features. They crossed the western fence and walked along the foot-hills of Vellimalai to estimate what was the catchment area of rain water flowing into the pointReturn site. As the day wore on, they altered my way of thinking about farm ponds and taught me how I should design and build one.

Rain water falling on 10 hectares flows over the pointReturn site. Let’s pause here and get an idea of the volume of water that is implied. Annual rainfall in these areas is between 800 and 1,100 mm. To keep calculations simple let us take it as 1,000mm or 1 metre. Rainfall of 1m on each sqM is 1,000 litres of water. A hectare is 1,000×1,000 = 10,000 sqM. So water arriving from the skies on each hectare of pointReturn’s catchment area is 10 million litres. On ten hectares, it is 100million litres of water annually. Yes, it is not spread evenly throughout the year but arrives in just over 100 days. Still it’s an incredible wealth. Discounting for diversions, local percolation on the way and reduced rainfall, it’s still a great quantity. Yet, this 15 acres of land had been abandoned as worthless when I bought it. Water running over it has been allowed to become destructive, scouring and carrying away the valuable top soil away. There are possibly millions of similar denuded acres in the country. Why?

Because we, the individual Indian citizens, have gone to sleep on micro scale solutions like water harvesting. We have conveniently put the onus on the government to create lakes and tanks; we enthusiastically support hare-brained ideas like linking the rivers of the nation at costs of trillions of rupees. We behave like this because the responsibility for any of these will not arrive on our door steps. We then have the luxury of sitting and complaining about the inefficiency and corruption of the state. The more we have been connected by education, communication and transportation, the less local we have become. India ranks among the top 5 countries of the world in terms of annual rainfall but our agriculture is in deep crisis.

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