A severe decline of 3 metres in the groundwater levels of the regions of Maharashtra, is haunting the authorities and people. The rainfall deficit and overuse of groundwater for irrigation during this year’s dry spell are the leading causes for this situation. City’s daily quota of water is being cut down, to quickly handle the crisis. However, the problem needs more sustainable solutions like rainwater harvesting.
Maharashtra is the third largest state of India, area-wise and second-most populous state. It has an economic importance for having the largest state economy and contributing 15% towards the nation’s gross domestic product. Being the most industrialized state, the product and service sectors are most prevalent and the population from other states of India is seeking an opportunity to make themselves a part of the state’s living. This trend has implications of its own. The larger settlement is putting pressure on the availability of natural resources for everyone, especially at the time of crisis.
The monsoons of 2018 are recorded to cause 30-50% rainfall deficit, in most of the tehsils of Maharashtra. There were long dry spells and to meet the food demand, farmers had to pump out more water from underground, leading to a dangerous decline in water levels beneath the ground.
The reports from IMD and GSDA
The India Meteorological Department (IMD) has presented the rainfall statistics for Monsoon 2018. In a gist, out of 353 tehsils in Maharashtra, 86 tehsils reported 0-20% rainfall deficit. 61 tehsils have reported 20-30% rainfall deficit while 109 received 30-50% rainfall deficit; 27 tehsils in Maharashtra received more than 50% rainfall deficit than average rainfall.
Consequently, the greater amount of water had to be extracted from the underground, through borewells, which further declined the groundwater levels. Marathwada and north Maharashtra regions were recorded to have the highest groundwater depletion levels.
Since Marathwada has received 22% less than average rainfall this monsoon season, 4,572 villages from Marathwada region have reported 1-2 metres decline in groundwater levels. The survey report by Groundwater Survey and Development Agency (GSDA) mentions the groundwater level decline of more than a metre in 11,487 villages, by 1-2 metres in 5,556 villages, by 2-3 metres in 2,990 and more than 3 metres in 2,941 villages of Maharashtra.
Apparent causes for the decline in groundwater level
Due to scanty monsoons, the farmers had to retrieve excess water from underground. Out of the total area under irrigation, 28.75 lakh hectares or 71% of the agricultural land uses groundwater for irrigation. The total groundwater can be segregated based on its area of use- 85% for irrigation, 10% for industries and only 5% for domestic consumption. To meet the demand, a continuous pressure is being laid on the underground water source.
Also, water percolation is difficult in Maharashtra due to the presence of a high percentage of basalt rock (82%). This further creates heavy dent between water table recharge and its consumption.
The absence of proper execution of state-wide or nationwide water policy is another reason for overexploitation of the groundwater.
Can rainwater harvesting, and other water conservation methods help Maharashtra?
The investment made in the installation of rainwater harvesting structures and other water preservation setups can release a significant amount of burden from the groundwater storage. The modern tools and RWH products are available to collect, transport, filter and store the rainwater. The preserved water reserves are not only used in day-to-day activities, but several methods can help in increasing the level of exploited water table.
Capturing rainwater and filtering it to get stored for future use is the practice of rainwater harvesting. There are basically three methods of rainwater harvesting in an urban setup:
Rooftop RWH – the water is collected on rooftops of the buildings, and transported to an underground or surface storage tanks, via conduits or pipes. This method does not contribute much in recharging the groundwater, but it surely helps in reducing the over-extraction of water from under the ground.
Surface RWH – the runoff water that flows on the streets/roads are made to percolate into the ground by constructing rainwater harvesting structures, thus recharging the groundwater table. The structures can be made as rectangular shaped perforate slabs on roadsides or the circularly shaped slabs for open grounds and spaces. The structures are efficient to recharge the underground aquifers with the desired quality of water, even in the event of scanty rainfall.
Groundwater Recharge – these are special additional structures made near borewells or wells to recharge the groundwater using the runoff from surface rainwater or nearby natural water sources like pond or river. Read our blog on groundwater recharge to know about these structures in more detail.
- Open jointed paver blocks with 25-50% gaps, instead of paving the garden and park paths with concrete or asphalt, helps in natural absorption of the rainwater by the grounds.
- Percolation tank is another option to improve the level of groundwater by recharging wells and borewells.
- To help in water percolation by the ground, constructing small tanks in the fields prove to be an effective solution.
- Construct bunds and catch drains along the field boundaries.
- Plant more and more trees in open fields or hillocks which could help in absorbing surface runoff water.
- Vertical drains constructed in wastelands can also help in percolation of water by the ground.
The state canal committee decided to cut down the city’s water quota by 15%. This may be a temporary solution to stop the exploitation of groundwater but in the long run, the authorities of Maharashtra must encourage rainwater harvesting and other groundwater recharge methods, at an individual as well as community level.
Chaitanya – Rainwater Harvest Products and Service Provider in Maharashtra
Stats regarding the decreasing levels of groundwater might be looking tough for the state of Maharashtra but the idea of rainwater harvesting and recharge structures are providing the hope it needs. We at Chaitanya Rain Harvest Products and Systems have resources and engineered tools to help individuals and organization to take on the construction of RWH structures with full confidence. Whether you need a team of engineers for rainwater harvesting feasibility report or gravels for groundwater recharge structures, we are known to provide all RWH solutions under one roof.