The revival of traditional water conservation systems in India, such as the Eri Network, is crucial for addressing the water crisis

Conservationists are preparing to propose the inclusion of the Eri (Tank) Network in the Kazhuveli watershed region of Tamil Nadu for nomination to the esteemed World Monuments Fund Watch 2025 program. Spanning an expansive area of 740 square kilometers, this region features an ancient 'Eri' Network—a marvel crafted thousands of years ago—that has served as the lifeblood of agricultural practices for millennia. However, this invaluable heritage is now facing a perilous decline, prompting urgent calls for its protection.

But what is World Monuments Fund Watch?

Final call to nominate a site to the 2025 World Monuments Watch! Do you know a heritage site facing urgent challenges? A place where preservation can make a difference in your community? Become an advocate. Learn more: https://t.co/jyFH6MKKqg pic.twitter.com/usWlFrdSFh

— World Monuments Fund (@WorldMonuments) March 14, 2024

The World Monuments Watch is a nomination-based program that connects local heritage preservation with global awareness and action. Every two years, the watch provides support to places in need and the people who care for them, spotlighting new challenges and the communities worldwide harnessing heritage to confront the crucial issues of our time. At its core, the Watch’s call to action seeks to empower timely preservation efforts that improve the lives of communities. The 2025 Watch will include 25 places, each telling an urgent local story with global relevance. Through this initiative, the World Monuments Fund (WMF) partners with the people who know these places best, amplifying their efforts through advocacy, capacity building, and close collaboration with WMF’s expert team and professionals across the globe.

One such place on the minds of cultural heritage specialists Aghash Natarajan and Helen Crutcher, graduate students from the Brandenburg University of Technology Cottbus-Senftenberg, and Induja Gandhiprasad, an environmental conservationist from Auroville, is the Eri Network in Tamil Nadu.

If successful, the nomination will pave the way for pilot projects in Munnur village aimed at developing a heritage toolkit that can be replicated across the watershed and beyond. By fostering community engagement and drawing upon local expertise, these initiatives aim to ensure water resilience in the face of escalating climate change threats while reclaiming heritage as a shared community asset.

However, the Eri Network is not the only traditional water system in India that needs revival. India has a long and diverse history of civilizations, and there are many architectural marvels that are stunning to see and even more beneficial for easing work. One such invention is the indigenous water conservation systems built across various places. Let’s take a closer look at some of the traditional water conservation systems in India that can be revitalized in this modern era to combat the crisis of water depletion.

1. Eri System

First, let's discuss the topical system that is gaining attention for the World Monuments Fund Watch. The Eri or Tank system, practiced in the Kazhuveli watershed region in Tamil Nadu, is one of the oldest forms of water conservation systems in India. Since the state of Tamil Nadu has only one perennial river - the Thamirabharani River - earlier communities developed a system to conserve water. This system captures rainwater runoff from roofs or other hard surfaces like terraces and pathways into an underground reservoir called the eri. It prevents soil erosion, recharges groundwater, and prevents wastage of runoff water during heavy rainfall.

2. Taanka or Paar

Tannka’s or Paar’s are traditional tanks used to store water. These rectangular or circular tanks are mostly found in the desert regions of Rajasthan. They are typically built for family or public use, ranging in capacity from 1000 liters to even 500,000 liters, depending on the requirement.

3. Johads

Another type of water conservation system used in the states of Rajasthan, Gujarat, and other regions with low rainfall is Johads. Johads are small earthen check dams that collect and store rainfall, enhancing groundwater recharge and percolation—the process by which water descends through the soil due to gravity. They are abundant in some districts of Rajasthan, such as Alwar.

4. Khadins 

During rainfall, water runs off from higher areas like plateaus and valley plains. Khadins are long earthen embankments built to store this running water in regions that receive less rainfall throughout the year. These embankments, also known as bunds, can generally extend from 100 to 300 meters in length.

5. Baoli or Baori 

Baolis, Baori’s, or Vav, simply called stepwells, are designed to store water and are among the most well-known water conservation systems still functional in India. These stepwells were designed to fill and empty with the changing seasons, allowing access to the water via a series of cascading terraces, regardless of the water level.

6. Zing

In snowy and cold regions where ice forms, Zings are used to store water that forms by the melting of ice. These are small tank-like structures in which melted glacier water is collected and stored. Mostly found in the Himalayan region, a network of pipelines brings water to these tanks for further storage or distribution.

7. Kuhls 

The subordinate system of pipelines mentioned above is called Kuhls. These channels carry water from glaciers to the villages in Himachal Pradesh, Kashmir and other regions of the North. These Khuls or Kuls are lined with rocks to keep the mud from clogging.

8. Kunds

The kund system of water harvesting is used in areas facing water deficits. These are saucer-shaped catchments built with a gentle slope towards the center, where a vessel or tank-like structure is placed. Kunds are generally circular or cylindrical in shape, allowing them to hold water deep within.

9. Ahar Pynes

Ahar Pynes are retention ponds mostly found in Bihar. They are used to collect overflowing floodwater and are built with barriers on three sides, with one end open for the water to flow into nearby agricultural fields for crop irrigation.

10. Panam Keni

Panam Keni is a special type of well used by Kerala's Kuruma tribe to store water. These cylindrical-shaped wells are approximately 4 feet in diameter and depth. They are located in groundwater springs found in fields and forests, storing enough water to be used during the summer when water is scarce in those areas.

11. Phad 

A Phad is a century-old community-managed irrigation system. This Phad system is mainly operated on three rivers in the Tapi basin – Panjhra, Mosam, and Aram – in the Dhule and Nashik districts of Maharashtra. Sandams (escape outlets) are constructed to remove excess water from the canals through charis (distributaries) and sarangs (field channels).

12. Zabo 

Zabo translates to 'impounding run-off.' In the northeastern Indian state of Nagaland, there is a technique for gathering water that runs from the mountains. This technique, also referred to as the 'Theruza system,' was built centuries ago by the villagers of the Phek district to create a self-organizing system for managing their water, forests, and farms.

13. Ramtek Model

The Ramtek Model is a unique water management system first designed in the Ramtek Village of Maharashtra. Water is channeled through a vast network of tanks and Baolis, refreshing the water supply. It is a sophisticated network of channels with an underground supply, typically constructed by Malguzars (landowners) of the region, conserving around 60 to 70% of the water in that area.

14. Pat System

In this system, a diversion bund is built across a river system with the help of stones piled together and lined with teak leaves and mud to prevent any kind of leakage. It was first constructed in Bhitada Village of the Jhabua district of Madhya Pradesh to divert water streams from the hillslope to irrigation channels.

15. Jhalara

This water system resembles a stepwell, with stairs leading down three or all four sides of a rectangular-shaped tube to the ground where the water is stored. Water collected from the upstream terrains is stored at the bottom of a Jhalar and then supplied or stored for future use.