Is rain harvesting a solution to Bangalore’s water woes? Rain Water Harvesting is a way to capture the rain water when it rains, store that water above ground or charge the underground and use it later. This happens naturally in open rural areas. But in congested, over-paved metropolitan cities, we need to create methods to capture the rain water. A sample urban installation - Roof rainwater collection - in a metropolitan city · If you live in a single dwelling house or a multi-tenant apartment complex, you already have 80% of the RWH system. We just need re-orient the plumbing design. · The present design of the house will take all the rainwater from the roof and all the ground level areas surrounding the house and flow the water towards the street. (where it floods the street, clogs the storm drains and sewer lines for a few days, before flowing away as sewage water) · From the roof tops, bring the rainwater down using closed PVC pipes and direct it to a sump. Include a simple 3-part filteration unit consisting of sand, brick jelly and broken mud bricks · If you do not have sump, use a well. In many parts of the country, old wells when they go dry, is used as garbage dumps. Please clean the well and put the rain water into it. · If you do not have a well, construct a baby well (about 2ft in diameter and about 16 feet deep based on soil structure) · Other types of RWH - collect the ground water and stop their flow at the gate. Put a concrete slab with holes in it, build a 2 feet deep pit, across the full width of the gate. Collect and connect a pipe and flow the water to a well or a baby well. All costs are subject to local variations in different parts of India. Use these figures for budgetary purposes only. · Most often, the cost is from the PVC pipes. A 4" diameter PVC pipe costs Rs xx per linear foot. A 5" pipe costs lot more than a 4" pipe. · If you do not have a sump, include about Rs 5 per litre of water storage. So, a 10,000 litre size sump...