The concept of rainwater harvesting has been in existence for over the last few thousand years, since its inception of settlements and agriculture. These rainwater harvesting can be utilized for various aspects such as drinking water for livestock and doing household chores. In fact the brighter side of this notion has broadened for the provision of water for domestic purposes, clean and safe supply of drinking water and irrigation, which is on high demand in arid regions.
The main source of water is rain and if this rain water is agglomerated and harvested, the scarcity of water in water scarce region can be minimized even to the extent of elimination. One of the major panaceas in water scarce area where there is inadequate groundwater supply in terms of quantity and quality can be resolve by the technique of rain water harvesting. In urban areas, rain water available from rooftop of buildings and paved road during monsoon goes as a waste. This water can be stored in tank and can be used directly or indirectly by diverting to treatment plant through various ground water tapping arrangements and catchments which in turn can be utilized at the time of need. The paper aims towards the development of the framework for domestic rooftop harvesting for its useful purpose in Nagaland.
The papers include estimation of appropriate size of water tanks along with detailed reinforcement to be provided. A mathematical equation expressing the relationship between the required size of water tank and different rooftop areas is developed. The RWH systems for one household is designed considering the existing rain fall data. Designing of water tank expressing the relationship between rooftop area and its capacity is developed. Under this case study only roof with flat slab base is taken into an account due to that fact that it can accumulate more water.
Rainwater harvesting is an ancient technique of collecting rain water from various catchments and diverting them into reservoir for further usage. Rainwater is valued for its purity and softness. It has a nearly neutral pH, and is free from impurities such as salts, minerals, and other natural and man-made contaminants.
Nagaland has a largely monsoon climate with high humidity levels. Annual rainfall ranges around 70-100 inches (1,800-2,500 mm), concentrated in the months of May to September. Nagaland despite being blessed with ample amount of rainfall throughout the year, especially during winter have to face water scarcity. Looking into this matter a case study is being carried out in a city of Kohima with all the available data.
With increase in population the water demand has grown rapidly. Due to these higher usage levels of water in proposed area, water supply agencies are unable to cope up demand from available sources especially during winter seasons. As a result of which people living there have to face water scarcity. This further lowers the underground water level. The panacea to all these problems can be minimized or completely eliminated if proper rain water harvesting system is being adopted. Various components involved in rain water harvesting mainly of three components.
a) Catchment: It is an area through which rain water is collected it is further transferred to the storage tank through conveyance line.
b) Conveyance System: the water so collected in catchment is allowed to pass through various sizes of conduits known as conveyance.
c) Storage tank: It is storage for storing water. Design of the required size of tank depends on the amount of water that is likely to be collected.
ROOF TOP RAINWATER HARVESTING
Rooftop Rain Water Harvesting is the technique through which rain water is captured from the roof catchments and stored in reservoirs. Harvested rain water can be stored in subsurface ground water reservoir by adopting artificial recharge techniques to meet the household needs through storage in tanks. The Main Objective of rooftop rain water harvesting is to make water available for future use. The use may be temporary, seasonal or permanent except in years of exceptionally low rainfall. The rain water from the roof may also be used for recharging the ground water through nearby water sources such as open dug wells or bore wells. In terms of economic and human welfare it has a crucial role to play. Rainwater in many cases is most reliable, easiest to access, and least polluted source. It can be collected and controlled by the individual household or community as it is not open to abuse by other users. Some of the following advantages are
1. Provides self-sufficiency to your water supply.
2. Cost investment for pumping of ground water is reduced.
3. Supply better and safer quality of water.
4. Improves the quality of ground water through dilution when recharged to ground water.
5. Soil erosion can be eliminated and flooding in low lying area is avoided.
6. Comparatively less expensive.
7. This method is simple to adopt for all individuals.
8 It is easy to construct, operate and maintain.
- Quote paper
- Tsaroli Sangtam (Author), 2018, Rooftop Rain Water Harvesting. A Case Study, Munich, GRIN Verlag, https://www.grin.com/document/427542