Background
Concerns regarding the resource’s sustainability have been raised recently due to increased groundwater abstraction to meet rising residential and irrigation demand. However, it is possible to increase and sustain the levels of dwindling groundwater resources with the aid of an artificial well recharging system. The water cycle slowly and gradually replenishes groundwater reserves, but if drawdown is much more than precipitation, it dries. However, an artificial well recharge system can be employed to expedite the recharging process given the rising demand for this resource.
Introduction to wells
A well is a dug, driven, or drilled structure in the ground designed to access liquid resources, usually water. The most ancient and widely used form of well is a water well, which is employed to extract groundwater from underground aquifers. Water from the well can be brought to the surface with the assistance of a pump, manually using buckets, or through automated methods with large water containers. Additionally, it is possible to replenish the aquifer by injecting water back into it through the well, a process commonly referred to as well recharging. This recharging practice is primarily applicable to traditional water wells.
Classification of wells
Based on the type of aquifer the well is in, there are two major categories of drilled-well types:
- Shallow or unconfined wells are finished in the topmost saturated aquifer (the upper unconfined aquifer).
- Deep or confined wells are dug into an aquifer that is wedged between two impermeable strata through an impervious stratum.
Concept of well recharging
Deep water-bearing zones can be promptly replenished through the use of recharge or injection wells, which are part of subsurface groundwater recharge methods. To cover recharge wells, the surrounding material that encases the aquifer can be utilized. If this material has not yet solidified, a screen can be inserted into the well’s recharge zone.
Only in locations where there is a substantial impermeable layer between the soil’s surface and the aquifer that has to be recharged are recharge wells appropriate. They are helpful in regions with limited land as further wells can’t be dug out. With this approach, a comparatively high rate of groundwater recharging can be accomplished.
Ways to recharge a well
There are two most feasible ways to refill an aquifer that supplies the water to well:
- via Rainwater
There are further two methods, a well can be refilled by the help of rain water. One involves directing rainwater from rooftops to a filtration device, where it is then allowed to flow into the well like the way it is illustrated in the attached image. As seen, to begin with, rain water falls on the roof top and slides down to the roof gutter and with the assistance of network of pipes, it reaches a small filtration unit marked as ‘3’.
This filtration assembly has layers of charcoal, marbles and fine clay which purifies the water from any kind of impurity and finally the treated water is passed on to the well. The alternative is to create rain pits close to the well and let nearby rainwater fall into the pits. After a rain, the water will seep into the well under the action of gravity.
2. via Distant Water Body
Creating a vicinity (like lake) near the well region by making a downward slope near the extraction point i.e., well and drawing a water channel from a distant parent water stream. In this approach, we allow the water to spread around, in the vicinity area and ultimately seeping down to aquifer, getting filtered along, from the surface and subsurface layers. Here the water penetrates down due to the natural principle of gravity. This is a slow process and there is loss of water due to continuous evaporation, which happens at all temperatures above absolute zero (-273.16 °C).
Simple Process of well recharging
The overall process flow of all types well recharging is almost same. General rule is that water is brought near to the well, by any means and then water is retained there for some time and this water moves downwards and recharges the aquifer linked to our concerned well. The water level in well rises and the well becomes ready to use again
Benefits of recharging of wells
This technique is very beneficial for area with lesser space and lesser availability of aquifers. As digging new bores for every well cost, a lot of money and time. Building a mechanism which can replenish the existing well can solves this problem. Additionally, an increase in vegetation cover will produce more soil moisture when artificial recharge methods boost groundwater availability.
This could prevent soil erosion and result in an improvement in flora and fauna, including an influx of migratory birds and other wildlife.Artificial recharge improves water reservoirs and make it available for life for a longer period. Additionally, it can improve the aquifers’ water quality, which can subsequently be used for farming and livestock ranches close to the ocean.
Conclusion
Recharging wells is a phenomenon to restore and to intact water cycle. always a positive scenario especially for a water scare country like Pakistan. To combat with water scarcity , we have to take many measures, of water conservation, and to take it long way, water recharge. It is in our best interest to make some arrangements to replenish an existing well rather than discarding it. As there is not a consistent pattern of rains in Pakistan and the similar countries, with a different topography, and mostly due to climate change.
Preferred option would be to develop artificial lakes with deep bores, near pre-defined wells, artificial recharge, and drawing a water stream from nearby water bodies and recharge the groundwater at a higher rate compared to the pace at which we are depleting it. Water care focusing on water conservation, as well as water reuse, on rainwater harvesting, and groundwater recharging, to serve human in the best way of natural reserves.
In small villages of Pakistan, comprehensive approaches encompass recharging wells, solid waste management, and waste water recycling to foster sustainable environmental practices and community well-being.