You have different options to conserve rainwater. You can either build a storage tank or buy a synthetic tank from the market. While purchasing a synthetic tank from the market is the faster option, constructing a tank according to your custom specifications can get you a tank of the perfect dimensions depending on your requirements.
What you need first is the foundation for the storage tank. Prepare an area large enough accommodate the tank. The best building material for such tanks are ferrocement water tanks. The ratio of cement to sand is 1. 2. 3. The mortar should be spread in two layers of 12 mm and 18 mm thickness across the chicken mesh. Such water storage tanks are very cost efficient. One litre costs around 1.0 to 1.40 INR. Including the cost of all the construction equipment, the cost will still only amount to 1.20 – 1.60 INR. You can also build storage tanks below ground level. Hand pumps will be required to access the water in such tanks.