• Deepa Rao

Constant recharge of groundwater is the need of the hour

If you have the means to drill a well, you will almost surely find water beneath your feet. Even during droughts, groundwater takes a long time to be influenced. It's like a water reservoir that doesn't evaporate. It's because of this that it's so enticing for climate change adaptation and resilience.

Sustainable groundwater management is at the heart of the solution. It's vital to have a scientific understanding of groundwater and to manage it appropriately since if we use it responsibly and replenish it, groundwater might help address the problem.

Despite being submerged under the Earth's surface; groundwater plays an important part in the water cycle. Rivers, lakes, and wetlands are surface manifestations of groundwater that exchange flow with a groundwater reservoir that feeds them when they need water and eliminates some of their flow when there is plenty of it.

What is groundwater recharge and where is the need?

It's only logical that water conservation measures would become more important as the demand for water grows. Groundwater recharge, which refills aquifers, is one such measure. Artificial groundwater recharge can be done instead of waiting for time and Mother Nature to absorb and filter surface water. Surplus surface water is channeled deeper into the subsurface to accomplish this.

Artificial recharge has several advantages, including:

  1. recharging the aquifer beneath the ground.

  2. functioning as a reservoir for excess precipitation that can be collected during periods of water scarcity.

  3. avoiding seawater intrusion into aquifers in coastal locations.

  4. managing stream base flows.

  5. lowering the groundwater level, which lowers pumping costs.

  6. Because there is a considerable need for groundwater for drinking and agriculture in locations with limited surface water availability, artificial recharge is prevalent.

Smart infrastructure and methodologies must be assessed and used in order to solve this puzzle.

1. Basins for Spreading:

The spreading basins method uses surface flooding of water in basins excavated in existing terrain. For successful recharging, very permeable soils must be used, and a layer of water must be maintained over the soil. The amount of water entering the aquifer is influenced by three elements when employing direct discharge: infiltration rate, percolation rate, and horizontal water movement capacity.

Particle deposition delivered by water in suspension or in solution, algae growth, colloidal swelling, soil dispersion, microbial activity, and other causes cause clogging at the aquifer's surface. Spreading basins work best where there is a layer beneath the land surface and the aquifer, and clean water is accessible for recharging.

2. Fill Pits and Shafts with Water:

In these situations, surface flooding technologies for artificial recharge are rather unusual. Low-permeability lenses are common between the ground surface and the water table. In this instance, artificial recharge techniques like trenches and shafts may be successful in gaining access to the dewatered aquifer. The rate of recharge rose as the side slope of the pits grew.

To keep the high recharge rates running, unfiltered runoff water deposits a thin coating of silt on the sides and bottom of the pits, which must be maintained. Shafts can have a circular, rectangular, or square cross-section, and they can be backfilled with porous materials. Excavation above the water table may be coming to a halt. Recharge rates in both shafts and pits may diminish with time due to the accumulation of fine-grained debris and the clogging effect produced by microbial activity.

3. Detachments:

A ditch is a long, narrow trench with a shallow depth and a narrow bottom width. A ditch system is designed to match a certain location's terrain and geological circumstances. A series of trenches running down the topographic slope could be part of a ditch and flood-control project's design. The ditches could culminate in a collection ditch designed to transport away any water that does not penetrate, preventing ponding and the accumulation of small particles.

4. Wells for Injection and Recharge:

Deep-water bearing strata are immediately recharged via injection and recharge wells. If the earth materials are unconsolidated, recharge wells could be dug through the material overlaying the aquifer and a screen erected in the well at the injection zone.

Recharge wells are only suitable in areas where the soil surface and the aquifer to be refilled are separated by a thick impermeable barrier. They're also beneficial in areas where land is scarce. This method allows for a rather high recharge rate. The water level in the recharge well can climb excessively high due to a clogged well screen or aquifer.

5. Surface Dams:

A higher-pressure head to a lower-pressure head is where groundwater flows. This will help in semi-arid areas, especially in the upper reaches where groundwater velocity is high. Indirectly, more surface water can be used by accessing more groundwater in the upper reaches, reducing influx into lower supply zones. Groundwater is stored in subsurface dams or manmade sand storage dams made from natural aquifer materials.

6. Farm Ponds:

These are traditional rainwater collection equipment. Farm ponds are small storage tanks that collect and store rainwater runoff for irrigation and drinking. Farm ponds are split into three types based on their construction style and adaptability to diverse topographic conditions: dug farm ponds for flat topography, embankment ponds for hilly and ragged terrains, and excavated cum embankment type ponds for excavated cum embankment type ponds.

The location of agricultural ponds is influenced by rainfall, land topography, soil type, texture, permeability, water holding capacity, land-use pattern, and other considerations.

7. Streamlet's Historical Large Well:

If there are any old wells near the streamlet, connect drains to allow water from the streamlet to enter the well. The historical wells act as a recharge well in this case, providing for greater groundwater quality. Check dams are small barriers that are erected across the flow of water in shallow rivers and streams to collect rainwater. The little dams hold excess water in a small catchment area behind the structure during monsoon rains. The pressures formed in the catchment zone force the impounded water into the soil. The principal environmental benefit is the replenishment of nearby groundwater reserves and wells.

9. Alternative waters:

Alternative waters are sustainable water sources that aren't derived from fresh surface or groundwater and help to meet the need for fresh water. Alternative water sources include the following:

  • Rainwater collected from roofs

  • Stormwater captured, reclaimed wastewater, graywater, and captured condensate

  • Additional sources of alternate water

  • Discharged water from water purification procedures

  • Water from the foundation and water from the blowdown

  • Water that has been desalinated.

  • Atmospheric water generation

Based on this concept of Atmospheric Water Generation (AWG), Maithri Aquatech has developed MEGHDOOT — a sustainable water solution that generates clean water from the air without relying on ground or surface water.

MEGHDOOT generates clean water by sucking air into the system, condensing water vapour in the air into liquid water, filtering it through a multi-stage filtration process, and dispensing it as needed. The produced water is safe to drink and complies with World Health Organization (WHO) and Indian Drinking Water Quality Standards.

This environmentally beneficial solution has zero water waste and zero carbon emissions, can run on renewable energy and is a renewable energy source. The solution is built making use of a modular architecture, allowing it to generate from tens of litres to millions of litres of water, while itself being a decentralised source of water. With water being a universal requirement, MEGHDOOT is scalable even in terms of the wide variety of applications. Our company is dedicated to providing potable water solutions to meet the requirements of underserved societies on one side to large corporate offices, government undertaking as well as catering to the potable water requirements of people on the move in places such as railway stations, bus stops, airports etc. The agricultural water needs can also be addressed by aligning with sustainable technologies.

This alternate source of water helps groundwater to recharge and is a perennial source of water on this planet.

Learn from our experts about how Maithri’s water-related solutions are providing alternative sources of water that not only reduce the dependence on surface water but also aid in the recharge of groundwater by not completely extracting it.

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