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.
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.
Parts of Asia and South America have mountain regions prone to a high risk of flooding due to mountain lakes breaches and bursts.
In India, the Himalayas are home to a large number of glaciers. States like Jammu & Kashmir, Ladakh, Uttarakhand, Sikkim, Arunachal Pradesh, Assam and Himachal Pradesh are vulnerable to this phenomenon because of a large number of mountain lakes.
Mountain lakes often have base and walls made of debris and loose rocks. As the climate warms, new lakes are forming, and the dimensions of existing lakes are increasing in size, causing them to hold even larger quantities of water.
Over time, snow accumulated in mountainous regions compressed into glacial ice. As temperatures rise, glaciers melt and carving large arena shaped depressions in the landscape. Retreating glaciers leave behind rocks and debris creating a wall or a natural dam to block the flow of water.
Various geological processes, such as tectonic activity, create natural depressions in mountains when movements in the Earth’s crust occur. Water flows from snow-melt, seasonal rainfall or cloud bursts replenish glacial lakes or mountain lakes in elevated regions.
Increasing changes in climate patterns, including more intense and frequent storms, altered precipitation patterns, and temperature variations are already influencing the hydrological cycle globally. The unique topography of mountains enhances the likelihood of notable phenomenon which leads to massive flash floods.
The dynamic mountain landscape, combined with natural and human-induced factors, contributes to the complexity of water flow patterns. These complex factors lead to increased volume and velocity of water flow from mountains to downstream plains. This causes flooding, potential damage to buildings and crops downstream.
Here is a clip from recordings done by our team from such locations.
Cloud Bursts: In mountainous regions, the terrain’s elevation forces moisture laden air to keep rising. As the air rises it cools, reaches its dew point and rapid condensation occurs. This process is known as orographic lifting. The primary cause of cloud bursts is the rapid condensation of moisture in the atmosphere, leading to sudden and very heavy rainfall in a short period over a localized area. This intense rainfall over a short duration leads to flash floods and landslides in mountainous regions.
Landslides: Due to combination of geological, climatic, and human-related factors, landslides are evidently the most common and devastating occurrences in the mountains. Some factors which facilitate landslides are:
Intense or prolonged periods of rainfall or rapidly melting snow that can saturate the soil quickly. This increased groundwater fluctuation can reduce soil cohesion, making it more prone to landslides, particularly along steep slopes.
Seismic activity, causing movements and adjustments due to tectonic forces both in the earthquake-prone areas and even in areas away from major fault lines. Seismic activity causes rocks and soil to lose stability and potentially trigger landslides.
Human actions like oil and gas extraction, mining and construction of reservoirs also contribute to low-level seismic activity. Vegetation helps absorb and slow down water runoff. Deforestation alters the natural stability of mountain slopes and leads to increased runoff.
Early warning systems and effective water management strategies can significantly reduce the magnitude of devastation caused by sudden downstream flooding and runoff.
As proactive preventive measures, expenses associated with such efforts are relatively inconsequential when compared to the expenditures involved in disaster management efforts. Such disasters lead to an incalculable loss of livestock, crops, homes and human lives.
Satellite pictures and drone cameras can aid in studying and monitoring potential landslide-prone areas, facilitating appropriate land-use planning to mitigate the risk of landslides in mountainous regions.
Regular mapping and monitoring of water bodies in mountainous regions, along with coordinated and controlled releases of water from reservoirs, are crucial measures to reduce the ferocity of floods in downstream areas.
We must prioritize preventative measures at the point of origin. This will have the maximum impact on the magnitude of the problem. Consider measures like removing encroachments and clearing the natural flow path to facilitate the free movement of water.
We can gradually reduce a slope without resorting to permanent civil work by using loose boulders and pebbles. To reduce flow velocity, we can create multiple small dikes in the flow path using loose boulders and pebbles.
Water flows from the high mountains do not just affect certain areas. These massive quantities of water ultimately reach from mountains to the level ground of the plains. Here, the water stands there for weeks, destroying crop in the fields.
Here are some observations of this situation in parts of Haryana adjacent to Himachal Pradesh in June-July 2023.
The calmer water which manages to reach the plains should not be allowed to spoil the crop by flooding, stagnating or as run off. This water instead it should be utilized in recharging the ground water aquifers by designing appropriate Rain Water Harvesting systems. This effort will not only improve the water table but will also improve the ground water quality.
The above paragraph makes little sense at the first read but therein lies an important message. Our minds are conditioned to read every line beginning from left to right, hence as we search the beginning of a new line, we hop our eyes over to the left. Let us take another pass at the paragraph, only this time let us read it more naturally, continuing to the line below from where the top line ends… like the meandering flow of water.
The reason why our minds struggled in the first attempt is because we are conditioned to read in a certain manner and our minds predictably expect the ordering of words to confirm with our expectations. This conditioning of our minds puts us in a comfort zone and restricts our minds from needing to do the hard work of exploration.
This conditioning of the mind impacts every aspect of our life and so is the case with Rainwater Harvesting efforts where a lack of critical thinking or out-of-box problem solving can very often result in rainwater harvesting systems structure design that is not just unnecessarily costly but also low in efficacy and durability.
From our years of experience and research in the field of rainwater harvesting, here are some common examples of how and why some designs are sub-par and often fail.
The most common perception about soil and ground water is that there is a thick layer of dry soil on the top and underneath this lies a space filled with water. The line demarcating them is indicating the ground water level. This imagination leads an inexperienced harvester to focus only on vertical rainwater harvesting, whereby he aims at making an arrangement by which the rainwater can directly be diverted from the surface and made to merge with the ground water underneath.
For this purpose, the designer inserts a set of pipes into a bore hole with few slots only in the last section of the pipe (first to be inserted) and thereafter focuses on collecting and diverting the rainwater through some filter system into the slotted pipe for a free fall and get released from the slots deep down in order to start recharge process as close to water table as possible.
In practical scenarios, this sort of a design either fails or is too expensive to build and operate (see details). The main reason is that the slots in the vertical pipes get choked by the suspended silt entering the pipe along with the rainwater. This necessitates the construction of a silt removal tank or a decantation chamber, which is not just adding to the cost of the design but also increases the chances of failure due to silting in chamber itself.
Very often, we see these failed designs being repeated as people assume that a more expensive system with a complicated design will be superior in features and performance. Rainwater harvesting systems are meant to support natural processes and thus complicated designs are more likely to fail than succeed.
An inexperienced approach tells one that any pit dug into the ground and fitted with cement rings with slots will be a good recharge structure since the rings will prevent collapse of the hollow pit and the rain water which fills the pit will come in contact of the soil through the slots the water will be absorbed by the soil.
The fact is that such a structure is sure to collapse since the water going out of the slots will first help silt to get suspended and thereafter flow back into the hollow pit. This will ultimately lead to not just the refilling of the hollow pit with sand but also create hollow space outside the cement rings and then the collapse of structure.
Similarly, there is a misperception that rainwater should somehow be filtered before it is put to any use or even stored. This leads designers to construct complicated silt removal chambers that attempt to remove silt from rainwater before letting the water pass into the slotted pipe into the ground. This effort is not only adding to the cost of the structure but is also increasing the chances of failure since most de-silting chambers get choked and fail leading to failure of rainwater harvesting system as a whole.
Furthermore, some rainwater harvesting systems are fitted with steel sieves for proper filtration of silt. Such systems choke even faster and may not last for even a single monsoon. The plain fact is that there is nothing in rainwater which needs to be or can be filtered by stainless steel wire mesh filters. The dissolved soluble substances if any, cannot be filtered by these filters and the suspended silt or plastic etc. will itself choke these filters.
We at SILVERON understand the limitations created by such conventional designs and poorly considered approaches to rainwater harvesting. We are always discussing and experimenting with new ideas to make the recharge process more effective, simpler and economical.
SILVERON’s design of rainwater harvesting recharge shafts give equal emphasis on horizontal and vertical rainwater harvesting. In view of the fact that within the soil strata at different depths there are columns which have the capacity to absorb, hold and transfer water laterally while the gravitational pull is naturally pulling the water downwards to the water table. Giving rainwater the opportunity to be absorbed both horizontally and vertically without obstacles ensures that rainwater recharge starts from root zone itself.
This means that with their simple and efficient design, SILVERON shafts work year after year without choking simply because the design is free of any potential choke points.
Years of experimentation, understanding & experience has led our team to design and develop artificial ground water recharge systems which are both cost effective and top of the ladder in performance and durability. A testament to our success is that thousands of SILVERON shafts are installed at multiple locations in India without a single failure.
Simpler designs call for some out-of-the box thinking and based on years of experience, understanding and exposure, SILVERON provides rainwater harvesting systems that are high in performance, durable and cost effective.
The Ranthambore National Park is situated at the confluence of Aravali and Vindhya mountain ranges i.e. the Great Boundary Fault in Northwestern India. It is a unique and highly bio-productive terrestrial ecosystem that enables all levels to optimally sustain life. In this ecological wonderland, The Royal Bengal Tiger flourishes in its best form.
The Ranthambore Tiger Reserve situated within the park is the western-most habitat of the majestic Tiger in the Indian subcontinent. The park is spread over 1700 km2 spanning Sawai Madhopur, Karauli, Tonk & Bundi districts of the Indian state of Rajasthan.
The park is bounded by the Chambal river in the west, which is one of the least polluted perennial rivers in the world. The seasonal rain-fed Banas river bisects the park. With the passage of geological time the Aravalis, one of the oldest mountain systems of the world, have weathered to yield more soils. On the other hand the comparatively younger Vindhyas have withered much less and support the growth of unique flora in the region.
This rich landscape is a major hub of biodiversity. It is home to viable populations of six species of predator cats (Tiger, Leopard, Desert Cat, Jungle Cat and Fishing Cat). Large populations of Jackal, Wolf, Hyena, wild dogs and marsh-crocodiles also rule over a food-chain with over 40 mammal species, including spotted deers & rare antelopes (such as Black-Buck, Chinkara and Blue bulls), 320 bird species, 40 species of reptiles and 402 species of plants.
Not so long ago, there existed many such forests along the foothills of Aravali and Vindhya mountain ranges. Unfortunately, owing to human population pressure and interference many such habitats have been lost.
It is worth noting that because of positive human intervention, the plateau of Ranthambore forest remains as the only big expanse of dry deciduous Anogeissus Pendula forest in India.
Modern conservation adopts the approach that natural forests should be left alone since it is a self-sustaining ecosystem. However, by artificially limiting the area for natural expansion and growth of forest cover, human activities continue to hamper nature reserves.
This can be observed by the ever increasing number of villages and settlements not just along the boundaries of forest reserves but also squeezing into forest areas for fodder and space.
In this era of nature conservancy, humans are still forcing increasing animal populations to get confined in smaller areas where they may become vulnerable and extinct due to natural infections, diseases and even greater competition for food and water.
Tiger Conservation at Ranthambore
Ranthambore is known for its large population of the endangered Royal Bengal Tiger. During the past few years, there has been a steady increase in the Tiger population in Ranthambore where the present tally is around 55.
This has been possible due to the multi-fold, dedicated efforts of the forest administration, use of modern surveillance technologies across the reserve, and continuous manual monitoring including fortnightly stock taking of wild animals.
The sincerity, commitment, passion and emotional attachment of the forest officials to this noble endeavor can be seen from top officials to the frontline forest guards posted round the clock at various check posts (Nakas) deep in the forest reserve.
The growing tiger density in Ranthambore forest has already paved the way for relocating some tigers to strengthen tiger populations in other reserves such as Sariska & Mukundra in Alwar & Kota districts of Rajasthan.
Ranthambore’s Climate, Topography and Water Crisis
The Park has a dry climate with three well defined seasons – summer, winter and monsoon. The hot & dry summer months last from March to June with maximum temperatures around 45℃, negligible relative humidity and hot dry winds. Winter generally lasts from late October till February with the temperature often ranging below 10 ℃ to 20℃. The monsoons with average annual rainfall of 800mm and about 35 rainy days per year, last from July to September.
The park landscape varies dramatically from the vertical slopes (cliffs & knolls) to the sharp and pointed hills as the geography changes from Vindhyas to Aravali ranges.
The park has an approximate elevation ranging between 300-500 meters above mean sea level with mostly rugged and hilly terrain. The Aravalis have ridges on one side and gentle slopes on the other with few small plateaus and valleys. Gazella Peak, the highest peak of the Vindhyas, has an elevation of 507 m.
The top tableland, locally called Daang & valleys called Kho are prominent geo-features dotted with springs & geysers. These valleys are the richest wildlife areas of the reserve making them favorite spots for the tigers.
Most of the narrow, seasonal monsoon-fed water streams are very short lived. The streams flowing in the northern tract drain into the Banas river and ones on the southern tract drain directly into the Chambal river.
The deep, long and narrow gorges created due to erosion caused by these short-lived streams has created ravines that are prominent features valuable in enhancing the flora and fauna of the region.
Water scarcity for wildlife in long dry-spells and peak summer months is a cause of serious concern for forest officials. This is especially critical for territorial predators such as Tigers and animal groups that cannot migrate large distances in search of water.
Solving the Water Crisis with SILVERON
On the official invitation of Sh. Arbind Kumar Jha, Asst. Conservator of Forests at the Ranthambore National Park, our CEO Sh. Sunil Sharma visited the Tiger Reserve on Oct. 24-25th, 2020. The purpose of this visit was to understand the landscape and explore possibilities for water conservation to combat scarcity of water for wildlife especially during peak summer months.
The early morning session gave a general feel of the forest and as luck would have it the day began with these lovely welcome sights.
The afternoon was spent touring interiors of the deep forest to gather insights on the scale of water scarcity and possible remedies.
The forest area calls for proper water management to ensure enhanced quantity of available water. This includes hydro-geological studies, stage-wise implementation of solutions and evaluation extending over multiple monsoons. It is also important that only minimal intervention is made and that too only in support of the existing natural systems.
At SILVERON we firmly believe that rainwater is an invaluable local resource and every effort must be made to manage, recharge and effectively use the water where it falls. Since fresh water becomes scarce, the logical approach would be to effectively control and utilize rainwater as far as possible before it is lost to runoff.
Based on observations from the site visit, here are recommendations we are working on developing:
Developing Bunds: The park is situated in a low-rainfall region with thin alluvium. The hilly terrain and steep to mild slopes facilitate rapid rainwater runoff. It is important to identify sites and make intermittent hurdles in the flow path using available stones and bush across small gullies and streams.
The spacing between these bunds will be decided by soil permeability and angle of slope at each site. The bunds must be closer on steeper slopes where permeability is less. This will prevent flowing water from attaining erosive velocity thereby conserving soil moisture.
The accumulation of small quantities of water behind the bund also facilitates percolation wherever possible. This technique allows harnessing rainwater locally and reduces erosion through runoff.
Recharging through abandoned bore wells: The park has a number of bore wells that were abandoned due to non-availability of water. These boreholes can be re-developed into groundwater recharge structures. Small streams flowing nearby can be guided towards such boreholes.
Rainwater percolating through these structures would find fractures at various depths and develop flow paths to enrich groundwater levels.
Rejuvenating Shallow Dug Wells: A number of shallow dug wells are scattered throughout the forest. These wells get their water through percolation from rock fractures and water levels in them keep declining in the post monsoon months.
These dug wells, some even managing to retain water throughout the year, are an important lifeline for wildlife. Each such well should be numbered and monitored on a monthly basis to ensure effective use of waterstock.
Dilapidated shallow wells should be restored, de-silted and cleaned to increase their holding volumes and prevent collapse. Further, repaired dug wells should be covered using secure frames and strong wire mesh to prevent these wells from becoming safety hazards for thirsty animals.
New well locations can be identified on the downstream side to collect and preserve more rainwater before run-off.
Rainwater Collection and Transportation: During monsoons, surface water is plentiful in small or large ponds and depression areas specially on the down stream side. This water can be effectively transported and used in times of need.
The forest does not have tall trees and the major fire risk is from dry grass on the ground. This threat is especially severe seasonally during the long dry-spells.
Water tankers can be placed at designated Nakas to transport water to locations running short of water. These tankers can be especially useful to extinguish bushfires or other emergency uses.
This technique improves availability of emergency water supply and reduces stress on natural reservoirs especially during the dry season.
Adopting solar water pumps: Replacing diesel pumps at wells with solar water pumps would also go a long way in reducing pollution, noise and wastage of water. With set levels, solar pumps can be programmed to extract only limited quantities of water each day.
The extra generated power can be leveraged to deliver water via pipelines to other areas or to higher locations for storage or pumping.
In the first phase, SILVERON offers to provide Ranthambore National Park services of their experts, material and manpower at no-cost to design & demonstrate methods of recharging abandoned boreholes and rejuvenate & equip existing wells with solar pumps.
This effort is a reflection of our commitment to conserving India’s natural biodiversity and the majestic Royal Bengal Tiger.
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.
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.