Tag: Public Infrastructure

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Rainwater Harvesting: The Key to Mitigating Flooding and Protecting Soil Health

In our previous blog, we delved into the swift cascading of water from upstream regions, unfortunately resulting in a rapid departure without replenishing groundwater aquifers.

Consequently, this water accumulates downstream, particularly in plains and farmlands, for an extended and undesirable duration. Besides the visible surface flow, there is an ongoing, invisible subsurface movement beneath the Earth’s surface.

When water falls on hills, it can infiltrate the ground, becoming subsurface water. Excess water accumulates in the subsurface if the soil is saturated or the terrain is poorly drained. It then flows downhill, potentially causing flooding through a process called emergence.

This type of flooding disrupts the delicate ecological balance in a given area, affecting the intricate relationship between soil and plants. Plants require a specific depth of aerated soil for optimal growth, with oxygen playing a vital role.

The Impact of Flooding on Soil

The aftermath of such flooding leads to waterlogged soil, nearing saturation and impeding aeration, creating anaerobic conditions. This depletion of oxygen in the root zone adversely impacts microorganisms crucial for supporting plant growth, restricting overall plant growth.

Water logging reduces soil temperature and increases dampness, disrupting biological activities within the soil. It also vastly affects operations related to soil enrichment and development, affecting irrigated agricultural lands.

Water logging often coincides with soil salinity, impeding the leaching of salts brought in by irrigation water. This exacerbates adverse effects, especially when salts from lower soil layers are transported upward by capillary action.

Rise in soil salinity disrupts nutrient absorption by plant roots, damaging plantations and altering the physical characteristics of the soil. The soil becomes less permeable to water and more prone to runoff, negatively impacting neighboring lands and vegetation. Even fodder grown in such soil may pose health risks to livestock.

Based on our three decades of experience, we have learned that flooding exerts a prolonged detrimental influence on soil. While immediate effects may not be readily apparent, long-term consequences involve a gradual degradation of soil quality, diminishing its water absorption capacity.

In reality, the water wreaks havoc both upstream and downstream, presenting a clear situation before us.

Case Study: Trial Bore in Flood-Prone Haryana

At SILVERON, we recognize the tangible and intangible losses incurred due to flooding in India, seeing it as an immeasurable national setback. We recognize the challenges of rapid infiltration posed by limited soil permeability or impermeable layers. We have proposed a strategic solution involving the implementation of drilling recharge shafts.

Our well-established design not only facilitates surface water infiltration but also intercepts subsurface flow, contributing to the replenishment of groundwater levels. The unlined bore design of our recharge shaft enhances its effectiveness in checking subsurface water.

Once water finds an easy path through the shaft, it establishes a regular route, attracting more water towards it. By enhancing the rate at which water permeates the ground, our solution holds the potential to significantly mitigate the impact of flooding.

We conducted a trial bore to test our shaft design in challenging flood management conditions, despite our confidence and experience.

As part of our social responsibility, we installed a Trial Recharge Shaft, at our own cost, in the flood-prone plains of Haryana. These plains experience annual inundation during monsoon as they sit below the mountains of Himachal Pradesh.

Our Endeavor

  1. We drilled the trial bore to appropriate depth to take advantage of soil strata having good absorption capacity and developed the recharge shaft following our standard basic design.
  • We deployed custom-designed Hume pipes, with a special 3 feet diameter and 8 feet length. These pipes featured holes of varying diameters (2, 4, and 6 inches) to facilitate water entry into the Recharge Shaft. Positioned at an 8 ft. length, 5 ft. of the pipe submerged into the ground, with 2-inch diameter holes positioned about 6 inches above the ground. Hole sizes are arranged in increasing order, considering the diminishing quantity of suspended silt as the water level rises.
  • A wire mesh barricade, standing at a height of 3 ft., was grouted around the Hume pipe, 3 feet away in all directions. We fill the space within the Hume pipe, between the pipe and the wire fencing with aggregate. This system prevents entry of suspended leaves, paper, polythene, and captures a portion of the suspended silt by reducing velocity. We then cover the top of the structure with wire mesh and aggregate.

These structures effectively mitigate the impact of running or collected rainwater, preventing serious damage to field soil or crops.

It’s noteworthy that each recharge shaft maintains a consistent intake speed, with observed likely intake flow around 200 cubic meters per day.

               Triumph is attainable solely through proactive endeavors.  

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Rain Water Harvesting : The need for a macro vision

We at SILVERON have been getting regular emails from people who have received notices from government departments because their properties lack proper Rain Water Harvesting (RWH) systems.

Since awareness & outreach about water conservation is an important mission for SILVERON, we often guide people, free of cost and to the best of our capabilities, on ways in which they could implement simple and affordable RWH systems.

One such email that we received lately was from a retired person from Bhilai who on a subsequent telephonic conversation narrated a distressing tale of bureaucratic harassment that is not uncommon.

This gentleman has a small residential house and usual financial constraints of a pensioner. He has been struck with a financial penalty for not constructing a RWH system in his plot and has been threatened that this penalty amount will be increased each year if he does not construct a rainwater harvesting system.

The recommended contractor gave an estimate of Rs. 70,000. He doesn’t have that kind of money to spare and has no knowledge about how to do RWH on his property.

Urban rain water harvesting
Rain Water Harvesting is for the public good

This is the sad reality where the whole burden of doing rainwater harvesting, water conservation and ground water recharge has fallen upon individual citizens with meager resources and no expertise in the field.

There is no doubt that the water crisis with rapidly declining groundwater levels is a serious issue of our times. However, our government agencies and civic bodies either ignore this problem completely or shrug it off on to individual citizens.

Consider a scenario where in response to an enemy attack on a country, the government instead of deploying trained armed forces, calls upon only untrained civilians to buy weapons with their savings, move to the battlefield and fight the enemy. The outcome will be complete chaos and defeat.

Consider for a moment, if a nation’s economy faces recession & unemployment and the government instead of taking appropriate fiscal and policy measures simply orders ordinary citizens to become entrepreneurs and provide employment to others while putting fines on those who cannot take such risks. The outcome will be an irreparably broken national economy.

Like the above scenarios, when it comes to environmental issues and the climate crisis our governments cannot simply ignore their responsibility and pass the buck onto ordinary citizens. It is also the government’s responsibility to protect our natural resources, provide clean air and water to the citizens.

Starting with the Ministry of Water Resources, central & state ground water authorities, local   municipalities and public health departments – all have the authority and resources to fulfill their prime responsibility of providing adequate quantity of high-quality water to every citizen.

The ground water table has not reached these precarious levels over night. It has declined every year. Region after region has gradually slipped from safe to critical to being marked as notified.

Authorities have looked the other way when rampant over exploitation of water resources has been continued unabated. Even when this problem has reached crisis proportions, these agencies have been unable to formulate an effective plan or put adequate rainwater harvesting infrastructure in place in order to arrest the decline of water table for decades.

However now the system suddenly wakes up and decides to make ordinary citizens, such as the gentlemen from Bhilai, do what the government machinery should have done for a long time.

Every expert in the realm of water conservation knows that rainwater harvesting is a site-specific effort and to do successful rainwater harvesting one needs various site-specific data-points such as the geophysical report, knowledge of topography, existing water table levels etc.

Hence, without providing any required inputs, structural designs or financial support and simply pressurizing untrained citizens to construct RWH structures on their properties is a meaningless & unscientific exercise.

Without hesitation one can compare this approach with the complete failure & ineffectiveness of the Chennai-model where people were forced construct rainwater harvesting structures that have had no positive impact of the groundwater table as the city remains critically water deficient during the dry season.

We have been trying to explain that rainwater harvesting is not simple and sooner than later water stands un-absorbed in most structures if these are built unscientifically. It is the job of experienced experts who know the science.

Ordinary tax paying citizens should be spared from the pressure of constructing rainwater harvesting infrastructure without any assessment, guidance, support and information from the concerned government agencies.

Their efforts may be pointless without large scale, scientifically built public infrastructure for doing Rain Water Harvesting. We need a macro vision.