Eco-friendly Rainwater Harvesting Ponds

SILVERON’s unique design for rainwater harvesting and groundwater recharge

Land surfaces are uneven. After a rain shower, rainwater can often be observed to flow from higher ground to low-lying areas. As rainwater flows, it collects suspended silt and salts from the soil and accumulates at low points – as puddles, ponds, lakes, streams or even around urban infrastructure such as roads, housing societies and underpasses.

These pools of rainwater are a common sight during the monsoons. They spread over a large area making evaporation easy and quick. This evaporation leaves behind the silt and salts to quickly deposit on the ground in that area.

As this cycle repeats, monsoon after monsoon, gradually the low land becomes hard and non-permeable leading to 100% loss of collected rainwater by way of evaporation.

To help conserve rainwater, we at SILVERON decided to identify such natural locations where water collects and also map the flow path of rainwater coming into these locations.

Thereafter, we worked on remodeling the landscape such that the area available for water to spread and lost due to evaporation is reduced. We enhanced the water holding capacity of the selected spot by excavation.

From our experience and insight, we know that merely building a pond to collect rainwater is not sufficient for rainwater harvesting. This is because the surface of the freshly dug pond would allow percolation of water for one or two monsoons and saturate after that, becoming hard and impermeable.

To continue using these ponds year after year for rainwater harvesting and for helping improve soil-moisture & groundwater levels, we installed SILVERON recharge shafts within this pond. This ensures that the water isn’t merely collected but also finds an artificial pathway to enrich the underground aquifer.

Rainwater Harvesting Shaft installed at the base of a recharge pond.

We recognized that rainwater flowing freely through fields and farms over large distances tends to gather considerable quantities of silt that is the finest particles of soil that get suspended in rainwater. This silt eventually starts filling up the ponds each year.

Silt accumulation is an unavoidable, natural phenomenon that can over the years cause rainwater harvesting systems to degrade in performance. SILVERON designed a novel system for silt-removal that sits in the flow-path of the water just before it enters the pond. The flowing water is channeled through a silt removal tank and enters the pond only through the windows in its walls.

In this unique design, even if the silt removal tank fills to the brim, it would not hamper the flow of water into the main pond through its windows placed at a slightly lower level. Once inside the pond, water flows down over a stone pitched slope. This helps reduce its velocity and increases the deposition of any remaining silt as the base of the slope.

Thereafter the water fills the pond and gets absorbed into the recharge shafts by the holes on the side of the shaft.

The unique highlight of this SILVERON Rainwater Harvesting system design is that it does not confront nature or go against natural principles at any stage. This system stands as testament to SILVERON’s core design philosophy that is to support natural processes and work with nature to recharge groundwater. Ingenious designs for durable Rainwater Harvesting and Groundwater Recharge systems are a hallmark of SILVERON’s success.

SILVERON’s site-specific designs of Rainwater Harvesting systems recharge the groundwater aquifers and simultaneously enrich the root zone with moisture supporting trees, shrubs and foliage to grow.

Increased moisture content in the topsoil and vegetation raises the humidity in the air that in turn helps in the survival of diverse interdependent friendly organisms like bacteria and earthworm etc living both over and below the soil surface.

The vegetation generated by this enriched root zone forms a network of roots helping check soil erosion and improve plant and animal life.

This SILVERON project demonstrates the significance of developing ponds in the low lying area with recharge shafts in appropriate numbers to allow rain water to flow into the pond during rains and enrich the groundwater levels. 

The SILVERON Recharge Shaft

The ever-increasing population, urbanization, industrialization and rise in agricultural activity are major reasons for growing water demand. Rapid decline in the water table can be attributed to over exploitation of ground water resources for meeting these demands.

The basic purpose of artificial recharge of groundwater is to replenish water into aquifers that have depleted due to excessive groundwater extraction. Artificial groundwater replenishment systems involve techniques that modify the natural movement of surface water and use civil construction methods to enhance the sustainable yield of groundwater in areas where over extraction has depleted underground aquifers.

SILVERON’s dedicated team led by Sunil Sharma started experimentation to determine the various factors affecting groundwater conditions such as thickness of alluvium, depth to rock, the extent and depth of aquifer and quality of ground water. The team conducted several Geophysical Vertical Electrical Soundings  in the targeted areas.                                          

In our earlier blog Geophysical Survey: An essential tool for Rainwater Harvesting, we discussed the importance of variations in soil formation and presented sample data from our records showing major variations in ground strata.

Explains Ground Resistivity Tests for Rainwater HArvesting
Clockwise from top left: (a) Soil-Layers cross-sec view (b) Team SILVERON performs Ground Resistivity Test (c) snapshot of Soil Resistivity Testing and (d) Imaginary Ground Profile Illustration

Geophysical measurements are based on the fact that subsurface consists of a sequence of distinct layers of finite thickness. Each layer is assumed to be electrically homogeneous and isotropic and the boundary planes between layers are assumed to be horizontal.

Lessons from Field Experiments

Based on the Geophysical Survey and analysis of soil samples obtained from various depths while drilling trial bores using a Rotary drilling machine, it was observed that the changing compositions of soil components are very diverse. The soil strata keeps changing as we drill deeper into the earth and we are likely to encounter some layers that absorb more water, some which absorb less and some which absorb no water.

Since it is impossible to modify this naturally occurring soil strata, hence the research team came to the conclusion that for rain harvesting, Diameter of the recharge bore has less meaning while its depth is more important.

Team SILVERON also studied existing rainwater harvesting designs and observed that most structures had worked well in the initial months but gradually their efficiency reduced, and water started stagnating in the structures. This happened as most existing structure designs were not in line with natural laws but rather attempted forcing water absorption against natural processes.

The conclusion drawn was that for rain harvesting, supporting natural process is a sure path to success while going against nature is a recipe for failure.  

In view of the above valuable lessons, Sunil Sharma and his team started experimenting with multiple design ideas to be able to develop an Eco-friendly shaft design which would recharge the ground water in a sustainable way closest to the natural recharge process.

The Vision

SILVERON’s dream was to create a Rainwater Harvesting System that recharges ground water aquifers and simultaneously enriches the root zone with moisture supporting trees, shrubs and foliage. The vegetation generated by this enriched root zone forms a network of roots, binding the soil together to check soil erosion and provide fodder for animals.

Increased moisture content in the top soil and vegetation raises the humidity in the air that in turn helps in the survival of diverse interdependent friendly organisms like bacteria and earthworm etc living both over and below the soil surface.                                   

The conceived design would allow water to flow down an unlined borehole in direct contact with soil starting from the root zone. This matches the natural process where the rainwater is not flowing through artificial ducts such as a failure-prone slotted pipe system .

An Ingenious Design

We had determined that the soil profile is not uniform and there are layers of varying composition, porosity & permeability. It is conceivable that in the natural process, rain water on the surface would runoff since it was the easiest path and droplets which percolated into the ground due to gravity encounter other obstacles in the flow that may delay movement and point of contact with groundwater.

Slow Natural Ground Water Recharge

To facilitate both vertical and horizontal flow of water across the varying permeability of soil strata, SILVERON shaft depth was planned in a way that pierces through all layers and provides easy passage for the flow of water. The shaft’s bore hole is filled with material of high permeability providing an automatic connection between all layers in the ground.

Natural Ground Water Recharge supported by Rainwater Harvesting Shaft

It was observed that the recharge shaft had its own absorption (or intake) speed and any excess quantity of water reaching it would tend to runoff on the ground surface.

Encouraged by the success of recharge due to the vertical inter-connectivity that the shaft provided through natural formations inside the ground, it was decided to interconnect the adjoining recharge shafts by PVC pipe at the top so that the excess water entering the shaft could reach an adjoining recharge shaft without evaporation losses. This would help in avoiding flood hazard during storm showers by capturing the rainfall run-off which would otherwise overwhelm sewer or storm drains and also results in soil erosion.

Shaft Inter-connectivity boosts Rainwater Harvesting
Shaft Inter-connectivity boosts Rainwater Harvesting

The team while examining choked recharge structures observed that most rain water harvesters focused entirely on silt removal before the water was allowed to enter the recharge structure.  SILVERON recognizes that silt is the finest particles of soil, suspension of silt in flowing rain water is natural and since the turbulence is high during monsoon season, silt does not get time to settle making the water appear murky. 

The challenge is not only to ensure unhindered recharge performance in condition of normal silt naturally flowing into the structure but also to incorporate design features that would make silt removal and cleaning an easy & cost effective process.

Natural performance of the SILVERON Recharge Shaft in a village pond

SILVERON designed recharge shafts such that the silt which enters the shaft in the previous monsoon is removed easily by back wash arrangement before onset of next monsoon, at almost negligible cost and as simple process.

Removing silt through backwash

SILVERON shaft was designed conceived that rain water transported from roof tops, paved surfaces or low-lying areas to the recharge shaft would percolate and make the soil wet all around the entire depth of the borehole.

This in turn would attract naturally percolating rainwater coming from any direction, any distance and at any depth – since the shaft column is available to provide easy downward flow passage. The main design principle was to let nature develop an inter-connected network of streams below ground howsoever minute, since once created these channels would remain available as a path for water to flow when it rains.

Naturally Percolating Streams Find Recharge Shafts
Naturally Percolating Streams Find Recharge Shafts

The SILVERON Edge

We at SILVERON, understand the importance of considering all natural factors when designing a rainwater harvesting structure. These variations make the scope of work differ from location to location. Site specific work of such magnitude calls for years of experience and understanding on the part of the harvester.

Ingenuity, untiring efforts, trials, determination to succeed and decades of experience stand behind the performance of SILVERON Rainwater Harvesting Systems.

The wide acceptance and appreciation of the performance of SILVERON recharge shafts makes SILVERON the first choice in the field of water conservation.

Sunil Sharma – Our Founder & CEO

At SILVERON, we pride ourselves on our ability to meet client requests with enthusiasm, passion and most of all with innovative solutions that continue to provide outstanding results.

SILVERON’s journey started with one man’s focus and relentless efforts over decades safeguarding availability of water resources for the nation.

It gives us immense pleasure to introduce our visionary founder & CEO, Sunil Sharma, the inspirational force that powers Team SILVERON.

A forward-looking industrialist & environmentalist, he has done pioneering work in the world of Rainwater Harvesting (RWH) research & development in India with a singular goal – conserving water resources for our nation’s future.

The Journey

Sunil Sharma, an MBA (1979, Lucknow University) is a first-generation industrialist involved in manufacturing of formulations, electronic milk analyzers and specialized chemicals since 1982.

Over 2 decades ago, he started taking out time and part of the profits from his businesses ventures to experiment on soil and water relationship and pursue his passion for water conservation.

The initial purpose of these experiments was to understand the role of varying soil profiles and natural ground water recharge process along with analysis of the reasons which led to choking or failure of most existing artificial ground water recharge structures.

Years of untiring efforts has helped him uncover causes of high failure rates in conventional RWH system designs. Under his leadership, SILVERON has developed unique designs for economical & effective Rainwater Harvesting techniques. 

A testament to the success of Mr. Sharma’s design – under his leadership, SILVERON has installed thousands of RWH structures and as of date, each of these structures is giving excellent performance, year after year, without an instance of failure or collapse.

Talk on Rainwater Harvesting by Sunil Sharma, Founder & CEO, SILVERON

Corporate Projects & Success

SILVERON was born when Mr. Sharma’s passion for water conservation and his desire to benefit the society led him to take additional responsibility by associating with Coca Cola India to consult on Corporate Social Responsibility (CSR) matters and as an Advisor for Water Conservation (2003 – 2017).

Under his guidance, SILVERON installed 150 RWH structures and ensured creation of groundwater recharge potential equivalent to more than 9 times the groundwater extraction by the company in Rajasthan.

Over the next decade, Mr. Sharma has worked with Hero MotoCorp for water conservation by spearheading projects such as the installation of over 160 SILVERON RWH structures at Hero MotoCorp’s  Halol Plant (Gujarat), over 150 structures at the company’s R&D facility CIT, Kukus (Rajasthan), 140 structures for Neemrana Plant (Rajasthan), 21 each at Dharuhera and Gurgaon plant (Haryana) of Hero MotoCorp and 105 SILVERON RWH  structures at Chittoor in Andhra Pradesh.

Under Mr. Sharma’s guidance, SILVERON continues to expand its footprint with several projects with renowned corporate houses such as ISGEC and SSM in Yamunanagar (Haryana) & SCL, Noida (UP).

Social Engagement & Recognition

The water conservation efforts pioneered by Sunil Sharma & his expertise in the domain are of great value to SILVERON & the community of Water Conservationists.

His pursuits for preserving our water heritage has helped rejuvenate two 15th Century water bodies (Bawari) at Jaipur. These previously dilapidated & defunct step-wells are now are full of water round the year even today.

A recipient of the Jal Mitra Puraskar for his outstanding work in the field of water conservation, Mr. Sharma is regularly invited as a guest speaker by various management institutions, seminars pertaining to water related issues both by State as well as Central government agencies. He has also served as a member of Task Force constituted by Government of Rajasthan to address water issues for the state.

Vision for Water Conservation

Mr. Sunil Sharma firmly believes that nature supports every effort that does not interfere with natural laws and that there can be nothing nobler than Rainwater Harvesting because here is an act by which you are restoring the balance of nature & safeguarding our future generations.

The development of the SILVERON recharge shaft is the outcome of one man’s passion & innovation for Rainwater Harvesting. Mr. Sharma’s patience for trials and experiments on relation of water with different soil formations, his vision of incorporating maximum environmental benefits in one design and still keep it simple – is a foundation stone for SILVERON.

In a subsequent blog we will cover more details on the SILVERON Recharge Shaft – what led to its design as a ground water recharge system, how this design naturally improves opportunities for water to move within the ground by creating connectivity between porous formations and SILVERON’s RWH systems give excellent performance, year after year.

Understanding Earth & Soil

Experiencing nature gives us immense joy & pleasure. Be it in walking along a park trail lined by lush green trees, seeing vast green spaces or perhaps even seeing puddles and little streams after a rain shower. We love the sound of the humming birds, enjoy the weather and the fresh cool breeze. We love the sight of bright flowers all around and the squirrels crossing our path.

Does anyone spare a moment to think about the earth under their feet?

The world continues to move from the stone age to the space age because the principles of physics remain the same. It is only as we understand them better and experiment do we make advancements that benefit our lives.

We know more about the Sun, Moon and other planets in space but hardly know our Earth. Ever wondered how we can accurately predict solar and lunar eclipses but are caught off guard by disastrous flash floods, earth quakes, tsunamis and landslides?

The earth underneath us is so diverse and alive that the more one thinks about it, the more magical and mysterious it appears. It is the place where at each moment every law of physics is in action and which is holding within it the entire periodic table, innumerable organic and inorganic compounds and minerals and air and water and the living and the decomposing.

The core of the earth is about 6300 Km. from where we stand but humans have not been able to drill below 12 km (see ref). Most people do not even know that the ground well below our feet is may be hotter than the surface of the sun.

The layers of earth based on chemical variations from shallowest to deepest are:-

Layers of the Earth
  1. Crust: Earth’s crust is the outermost layer of earth and ranges from 5–70 kilometers in depth.
  2. Mantle: Mantle lies between Earth’s crust and dense super-heated inner core and is about 2,900 km. thick.
  3. Outer Core: Earth’s Outer Core is largely liquid iron layer of the earth that lies below the mantle. The outer core is about 2,300 km. thick.
  4. Inner Core: Earth’s inner core is the innermost geologic layer of the Earth. It is primarily a solid ball with a radius of about 1,220 km. The inner core is believed to be composed of an iron–nickel alloy with some other elements.

Our aim here is to give some insight to our readers that our earth is magical and that the earth’s resources are major components which impact the environmental factors which make planet earth habitable.

We do not wish to wade into a theoretical discussion about permeability or porosity of soil or about range of validity of Darcy’s law or velocity of flow of water. We would restrict our discussion to shallow depth of the earth’s crust since no man has ever explored the other layers in person – in fact at a maximum depth of 12kms, our civilization has barely scratched the surface.

The most common components with varying percent found in composition of the soil.

CapacitySandClaySilt
AerationGoodPoorMedium
Water-HoldingLowHighMedium
Compact-abilityLowHighMedium
DrainageHighSlowMedium
Leakage-preventionPoorGoodPoor
Result of tilling after rainfallGoodPoorMedium
Erosion by waterMediumLowHigh
Erosion by airMediumLowHigh
Capacity to hold plat nutrientsPoorHighMedium
Capacity to shrink or swellLowHighLow
Decomposition of organic matterFastSmallMedium
Soil components and capacity

Sand has pockets which hold air hence aeration is good and the voids are interconnected hence water holding capacity is low and drainage rate is high. This causes the compact-ability to be low and its use as a sealer to prevent leakage is not advisable.

This is the reason why it is beneficial to till the sandy land after rainfall. Planting of trees and bushes and construction of check dams are recommended to prevent soil erosion by air and water.

Some form of clay when added to sandy soil, enhances the cultivation output because it reduces soil erosion both by air and water and increases the compact-ability, water retention capacity & plant nutrient holding capacity of the soil.

If we explore the properties of soil we come across a list which is unending.

  • Soil not only serves as an anchor but also provides the required minerals and water to the plants. In fact this resource provides 99% of the food consumed by human beings.
  • Soil is a major raw material required for manufacture of many types of building materials. Soil is the foundation of construction projects.
  • Soil absorbs and cleans rainwater as it percolates through it and also holds it in the aquifers. This quality of soil not only serves as a source of ground water when needed but also protects us from floods and in time of droughts.

Interestingly, it has been observed that many animals deliberately ingest soil as it absorbs toxins, and facilitates digestion and checks diarrhea and it is also a source of rare minerals. The practice of eating soil is referred as Geophagy

Soil protection and conservation is very important since soil is the home for many organisms living in such interconnected harmonious diversity both inside and outside the soil like earthworms, snails, slugs, millipedes, centipedes, potworms, nematodes, bacteria, fungi and algae, to name a few. Aerobic processes of soil have a major role to play in waste management while handling effluent from septic tanks and elsewhere.

It is estimated that soil restoration will offset the effect of increases in greenhouse gas emissions and slow global warming. About 60% of the biotic content is carbon and this makes the Biological component of soil is very important. Even in desert crust, cyanobacteria which are microorganisms related to the bacteria but capable of photosynthesis, lichens and mosses capture and hold a good quantity of carbon by photosynthesis.

When we talk about water conservation, it is intricately tied to soil conservation as well. Preventing the erosion of soil through water conservation, rain water harvesting, green-belt development, responsible agricultural and industrial practices therefore has many inter-linked benefits – from improved soil quality to reducing the effects of global warming.

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 & outreachabout 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 couldimplement simple and affordable RWH systems.

One such email that we receivedlately was from a retired person from Bhilai who on a subsequent telephonicconversation narrated a distressing tale of bureaucratic harassment that is notuncommon.

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 gavean estimate of Rs. 70,000. He doesn’t have that kind of money to spare and hasno 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 crisiswith rapidly declining groundwater levels is a serious issue of our times. However,our government agencies and civic bodies either ignore this problem completelyor shrug it off on to individual citizens.

Consider a scenario where inresponse to an enemy attack on a country, the government instead of deploying trainedarmed 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 chaosand defeat.

Consider for a moment, if anation’s economy faces recession & unemployment and the government insteadof taking appropriate fiscal and policy measures simply orders ordinary citizensto become entrepreneurs and provide employment to others while putting fines onthose who cannot take such risks. The outcome will be an irreparably broken nationaleconomy.

Like the above scenarios, when itcomes to environmental issues and the climate crisis our governments cannotsimply ignore their responsibility and pass the buck onto ordinary citizens. Itis 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 notreached these precarious levels over night. It has declined every year. Regionafter region has gradually slipped from safe to critical to being marked as notified.

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

However now the system suddenly wakesup and decides to make ordinary citizens, such as the gentlemen from Bhilai, dowhat 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 anyrequired inputs, structural designs or financial support and simply pressurizinguntrained citizens to construct RWH structures on their properties is ameaningless & 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.