Hydrogeologist Vivek Grewal (https://www.linkedin.com/in/viveksinghgrewal/) joins host Pavan Srinath (https://www.linkedin.com/in/pavansrinath/?originalSubdomain=in) once again to unpack the basic science of groundwater and to explain how groundwater behaves in one of India’s most important hydrogeological regions.

Where does groundwater fit in the water story? Vivek explains why most of the world’s liquid freshwater exists underground, how rainfall becomes groundwater, and how rivers like the Ganga are sustained by flows beneath the surface.

The episode then breaks down how aquifers work from porosity and fractures to recharge and baseflow - while debunking common myths about “hidden underground rivers.”

Finally, the discussion turns to the Indo-Gangetic aquifer, explaining how it was formed and why regions like Punjab, UP, Bihar and Bengal face very different challenges - from depletion and salinity to arsenic contamination.

Drawing from both field experience and hydrogeological research, Vivek also explains why western India faces severe depletion despite large underground storage, why eastern India may have more water but different access and quality challenges, and how a better understanding of groundwater is essential for managing agriculture, drinking water and long-term water security.

Vivek Grewal (https://welllabs.org/vivek-singh-grewal/ ) is the Managing Partner with the Technical Consulting programme at WELL Labs. He has around 9+ years of experience in the water sector. He is passionate about taking the science of hydrology to the grassroots organisations.

Pavan Srinath (https://welllabs.org/our-team-pavan-srinath/) is the Managing Partner for Communications and Development at WELL Labs. Pavan is a communications and public policy professional who has spent over 14 years working in Bangalore's not-for-profit sector.

This episode is essential viewing for anyone interested in groundwater, hydrology, Indian geography, water security, agriculture, geology, and the science behind how water moves beneath the surface.

The WELL Labs Show features rich conversations on water, environment, land and livelihoods, from the people and partners of WELL Labs. Hosted by Pavan Srinath and occasionally guest-hosted by colleagues from WELL Labs, each episode explores complex environmental and social issues and helps you understand the systems and the dynamics better.

For all references and further readings related to the episode, visit https://welllabs.org/twls-vivek-grewal-pt3/

Subscribe to the WELL Labs YouTube channel @welllabs and watch all episodes on the official playlist here (https://open.spotify.com/show/6fDa6X5XqsHjUXZsWuDhkq)

Recording by Nabina Chakraborty and Vraj Acharya. Video editing by Ranjith Kumar S. Graphics and artwork by Aparna Nambiar and Kanishka Goyal. Podcast production and management by Nabina Chakraborty and Pavan Srinath.

Chapter markers:

00:00 Highlights

00:54 Intro

03:05 Understanding Groundwater

05:41 How does rainfall recharge groundwater

09:46 Misconception about the Hidden River Saraswati

11:13 Groundwater and Perennial Rivers

13:55 Aquifer Systems and their Characteristics

17:25 Check out the Water Data Podcast

17:46 India’s Groundwater Systems: 6 Aquifer Types Explained

21:12 How the Indo-Gangetic Aquifer Was Formed

23:54 How Punjab Went from Water-Rich to Water-Stressed

32:11 Subscribe to our YouTube channel

32:28 Lower Gangetic Aquifer: Water, Clay and Quality Issues

39:33 Why Groundwater Has Arsenic in Bihar & Bengal

41:25 Closing

Veena Srinivasan and Gayathri Muraleedharan join host Pavan Srinath on this episode of The WELL Labs Show to unpack the nature of Bangalore’s water crisis — what caused the severe summer crisis of 2024, why similar crises may recur, and what the city can do to avoid lurching from one groundwater emergency to the next.

The conversation explores why Bangalore’s water crisis is not a “Day Zero” reservoir crisis like Cape Town or Chennai, but fundamentally a groundwater crisis. Veena and Gayathri explain how the city depends on both Cauvery water and groundwater, why the most acute pain is felt in newly developed peri-urban areas and dense apartment clusters, and how Bangalore’s hard-rock aquifers, uneven topography, and hyperlocal recharge patterns make the problem difficult to predict and manage.

Drawing on WELL Labs’ work on urban water balances, groundwater dependence, wastewater treatment, and water reuse, the discussion examines how much water Bangalore needs, how much it receives from the Cauvery, and how much is being invisibly supplied through private borewells and tanker systems. They also explore why treated wastewater reuse, especially through decentralised sewage treatment plants in apartments and commercial complexes, may be one of the most practical ways to reduce pressure on the city’s fragile aquifers.

The episode also reflects on what has changed since the 2024 crisis: greater seriousness around water reuse, more interest from apartment communities in running STPs efficiently, efforts by BWSSB such as the Green Star Challenge, and the need for stronger incentives, better monitoring, groundwater recharge, sponge landscapes, and more realistic water pricing. The conversation ends with a hopeful but grounded argument: that while Bangalore’s water crisis is systemic, the city also has many solutions that can be acted upon locally — by institutions, neighbourhoods, apartments, and public agencies alike.

Veena Srinivasan (https://welllabs.org/veena-srinivasan/) is leading WELL Labs’ mission to transform scientific research into real-world impact by designing solutions that simultaneously create livelihoods and conserve the environment. In 2022, she was listed as one of the top-cited scientists in the world.

Gayathri Muraleedharan (https://welllabs.org/gayathri-muraleedharan/) is the Deputy Head in the Urban Water programme at WELL Labs. She is an urban and regional planner passionate about understanding complex urban challenges, and solving them through sustainable, inclusive, and action-oriented approaches.

Pavan Srinath (https://welllabs.org/our-team-pavan-srinath/) is the Managing Partner for Communications and Development at WELL Labs. Pavan is a communications and public policy professional who has spent over 14 years working in Bangalore's not-for-profit sector.

This episode is essential viewing for anyone interested in Bangalore’s water future, urban groundwater, wastewater reuse, city planning, climate resilience, and practical pathways to water security in growing cities.

The WELL Labs Show features rich conversations on water, environment, land and livelihoods, from the people and partners of WELL Labs. Hosted by Pavan Srinath and occasionally guest-hosted by colleagues from WELL Labs, each episode explores complex environmental and social issues and helps you understand the systems and the dynamics better.

For all references and further readings related to the episode, visit https://welllabs.org/twls-gayathri-muraleedharan-veena-srinivasan/

Subscribe to the WELL Labs YouTube channel @welllabs and watch all episodes on the official playlist here (https://open.spotify.com/show/6fDa6X5XqsHjUXZsWuDhkq)

Recording by Nabina Chakraborty, Vraj Acharya and Nanditha Gogate. Video editing by Ranjith Kumar S. Graphics and artwork by Aparna Nambiar and Kanishka Goyal. Podcast production and management by Nabina Chakraborty and Pavan Srinath.

In this episode of The WELL Labs Show, John Thompson , a leading researcher in development studies and sustainability, joins the host Arjuna Srinidhi, to unpack the idea of “Pathways Approaches” and what it means for building climate resilience in complex systems.

The conversation explores how dominant development pathways in agriculture, water systems, or food systems often become locked in through policy, markets, and institutional incentives. John explains how the Pathways Approach helps researchers and decision-makers move beyond these lock-ins by opening up multiple possible futures and examining who benefits, who loses, and what trade-offs different choices create.

Drawing on examples from food systems in Africa and ongoing work under the CLARITY, John discusses how diversification, experimentation, and stakeholder dialogue can help societies navigate uncertainty. The discussion also explores the idea of Transformation Labs, where researchers, communities, and policymakers co-design research, co-produce knowledge, and jointly explore pathways toward more equitable and climate-resilient futures.

John also reflects on how researchers can make decision-making processes more transparent and accountable — not by prescribing solutions, but by helping societies understand the consequences of different development choices.

CLimate Adaptation and Resilience In Tropical drYlands (CLARITY) addresses the critical need to identify equitable, sustainable and climate-resilient development pathways in tropical drylands. This Global South-led project will result in the creation of long-term assets (data and tools) and capacities to achieve transformational change.

The WELL Labs Show features rich conversations on water, environment, land and livelihoods, from the people and partners of WELL Labs. Hosted by Pavan Srinath and occasionally guest-hosted by colleagues from WELL Labs, each episode explores complex environmental and social issues and helps you understand the systems and the dynamics better.

Subscribe to the WELL Labs YouTube channel @welllabs and watch all episodes on the official playlist here.

Recording by Nabina Chakraborty and Vraj Acharya. Video editing by Ranjith Kumar S. Graphics and artwork by Aparna Nambiar and Kanishka Goyal. Podcast production and management by Nabina Chakraborty and Pavan Srinath.