INTRODUCTION ABOUT RAIN HARVESTING:
Rainwater harvesting is a method of Accumulation and storage of rainwater into natural reservoirs or tanks, or the infiltration of surface water into subsurface aquifers by connecting the catchment areas with PVC pipes and diverting them into Harvesting pits for reuse. NaturesCureHub will completely explain how to install a Harvesting pit and maintain the same forever with a very minimum investment.
Water is the most precious resource on the earth, we cannot imagine a minute without water. No monsoon will guarantee us sufficient rains and it is our intelligence which will allow us to store water using different methods and Rainwater Harvesting is once such great method where you don’t need to manually store water but the accumulation of water can help you fill water in underground which will be purified using some filters and can be supplied as a regular water for our day to day usage.
Rainwater harvesting is the best method to conserve water by diverting the water from the catchment area to underground for reuse before it gets mixed into a drainage. Most importantly the harvested water can be used for various purposes such as gardening, drinking, etc. The lands are becoming dry and the humidity is increasing day by day, that is because of not having enough underground water, the harvesting not only conserve water but can also minimize the humidity and helps maintain the stable atmosphere.
BENEFITS OF RAINWATER HARVESTING SYSTEM:
- Improves water quality in the ground through dilution
- Help you overcome from droughts
- Reduce the rainwater stagnancy on roads and flood hazards
- We can use the stored water for various purposes
- Rejuvenation of dried up wells
- Reduces the dependency on Municipal water
- Save future generations from water scarcity problem
- Reduces water and electricity bills
- Cost-effective and can be easily maintained
COMPONENTS OF RAIN HARVESTING SYSTEM:
- Catchment: The surface from which rainwater is collected for storage, it can be rooftop, landscaped area or a paved flooring surface. The catchment area is the area of that surface where the water is frequently accumulated during rains.
- Gutters and Down take pipes: PVC pipes will be installed to collect water from the catchment surface and divert the same to storage tank or the harvesting pits.
- Filters and first flush devices: Remove grit, dirt and the other wastage that the rainwater may transport from the catchment before the water enters the storage tank. When it rains after a long gap, the rooftops are usually very dirty and the rainwater also carries with it a lot of dissolved air pollutants, we suggest that you maintain your rooftop clean, especially in the rainy season to have fresh water harvested. A first flush device diverts the water from the first rain so that it does not enter the storage tank.
- Storage tanks: These can be above the ground or below the ground. One can install the capacity of storage depend upon the need.
- Delivery systems: Piping systems that carry the stored rainwater till the point of end-use.
Roof catchments: The rooftop is usually the most common catchment surface and can be flat or sloping.
- Smooth, hard and dense roofs are preferred since they are easier to clean and are less likely to be damaged and release materials/fibers into the water.
- The catchment surface should slope slightly towards the down take pipes so that water does not stagnate on the roof.
- A catchment that slopes towards a single direction, preferably in the direction of the sump/bore (well) will reduce piping costs
Ground-level catchments: If the storage tank is below the ground level, paved flooring surfaces and open grounds can also serve as catchments.
Rainwater yield and quality varies with the size and type of the catchment area, climatic conditions, cleanliness of the catchment and the surrounding environment. A smoother and cleaner catchment contributes to better quality and greater rainwater collection. Regardless of catchment material, there will be certain losses due to absorption, evaporation, and inefficiencies in the collection process. The run-off coefficient is a factor that accounts for these losses and indicates the fraction of the rainwater that leaves the catchment to enter the collection pipes. For example, a runoff coefficient of 1 indicates that there are no losses and all the rainfall that falls on the catchment reaches the down take pipes and a coefficient of 0.8 indicates that only 80% of the incident rainfall reaches the down take pipes.
TYPES OF RECHARGE PITS:
1) RECHARGE DRY BORE (WELLS) THROUGH INJECTION METHOD
2) RECHARGE UNDERGROUND WATER BY INSTALLING RAIN HARVESTING PITS
- HOW TO RECHARGE DRY BORE WELLS:
- Inspect your area by investigating the most diverted water and try to install the pits near them or dig the well close to the dry Bore (Well) so that the water level in that area will improve and your Dry Bore (Well) will easily get recharged with sufficient water.
- Once you identify the place, you can dig the well with a size of 4 feet width, 6 feet height and 6 feet deep. Please make sure there is no brick construction or cement plastering inside the well
- Install a PVC pipe from below the pit and arrange holes every 3 inches up to 3 feet like it is shown in the above image and secure those holes with steel mesh
- In the sandpit, first 3 feet put 60 MM or 40 MM granite and above that put 20 MM Gravel chips for 1.6 feet and above that put small stones (the stone which you find after filtering the sand) or put sand for 3 inches and for remaining 1 feet 3 inches the cement plastering should be done on all the sides of the pit. Please see above image for clear understanding.
This type of recharge pit with above guidelines can suck any type of heavy rainwater and store water into the ground level, one can have a successful harvesting pit if the above guidelines are followed properly and live in a hassle-free environment.
2) RECHARGE UNDERGROUND WATER BY INSTALLING RAIN HARVESTING PITS
A recharge pit can be invisible when finished and can also be installed in Driveways in apartments because it will be covered with grills. As it is filled with stones, it doesn’t present any danger like an open well. The percolation rate of a recharge pit is much less than of an open well. The water percolates slowly because there is no hydrostatic pressure in the pit.
A recharge pit allows the rainwater to replenish groundwater by recharging the underground aquifers. It can be built to recharge a borewell or just to help the water harvesting from the catchment areas.
- Inspect your area by investigating the most diverted water and try to install the pits near the most percentage of water flow where you feel the water is wasted, you can do this by observing the catchment area and the release of that water.
- Once you identify the place, you can dig the well with a size of 4 feet width, 8 feet height and 8 feet deep. Please make sure there is no brick construction or cement plastering inside the well
- In the sandpit, first 4 feet put 60 MM or 40 MM granite and above that put 20 MM Gravel chips for 2 feet and above that put small stones (the stone which you find after filtering the sand) or put sand for 3 inches and for remaining 1 feet 9 inches the cement plastering should be done on all the sides of the pit. Please see above image for clear understanding.
- Construct 6 inches or 1 foot wall on top of the pit and plan to install 6 inches PVC pipe from the top catchment area which can directly connect to harvesting pit, this method will allow the water to divert into your harvesting pit.
COST OF CONSTRUCTING THE RAIN HARVESTING PIT
Rainwater harvesting methods are site-specific and it is not easy to analyse the general cost, it always depends upon the size of the pit and the amount of the water diversion.
I am providing the general idea of the recent harvesting pit constructed near my place and the size of the pit is 4 feet width, 20 feet length, 8 feet height and 8 feet depth.
The labour cost incurred is 20000 Rupees
The material cost is 30000 Rupees
1 pit has costed around 50000 rupees and they have installed 5 pits with the cost of 250ooo Rupees.
The above method is the excavation of Soil, but excavation of rock will cost you more than double because a lot of labour work will increase to break the rocks.
IMPORTANT TIPS FOR MAINTAINING CLEAN RAINWATER DURING MONSOONS:
- Every year during Monsoon season, clear the catchment area and keep it clean so that the water which will divert to harvesting pits will go as a clean water
- Do not through the garbage in harvesting pits and please make sure to avoid throwing plastic related waste nearby places.
- Every year remove the top portion 3 inches stones or sand from the harvesting pit and clean with water and keep it back in the harvesting pit, this will allow your pit to suck water even it is heavy rains just in minutes. This method will allow you to get benefited from rainwater usage and your water storage will also increase to enough levels.
1) Every year 92% of the rainwater will go waste
2) After implementations of Harvesting Pits, one monsoon rainwater harvesting can provide you 3 years of enough water supply
3) It will never be an obstacle for house construction
4) If you install Rainwater sump along with the harvesting pit then you can save water bill because you will be using your water
5) You can get clean water free of cost
please read our next blog on Millets by clicking below link