(Feature Image: Merging point of of Badiyar gaad (left) and Yamuna river (right) at Gangani in Badkot, Uttarakhand. BS Rawat/SANDRP)

New research published this week reveals a startling change: the oxygen levels in inland waters has been dramatically reducing since 1900, due to human activities including big dams and pollution. This condition leads to dead fish, collapsing food chains and reducing water quality, among other impacts.

There are simultaneous processes ongoing in inland waters leading to production and consumption of oxygen. The location and processes for both the production and consumption of oxygen has been changing during 1900 to 2010. The Global oxygen consumption in inland waters, net of production has gone up by over 100% from 0.26 Pg/year in 1900 to 0.53 Pg/ year in 2010. While earlier climate change was considered major contributor to this reduction, new research shows it is big dams and pollution that are much bigger contributors. Inland waters now pull nearly 1 billion tons of oxygen from the atmosphere every year — half as much as the entire ocean emits back.

Maharashtra Chief Minister Devendra Fadnavis, brushing aside the concerns of forest officials, opposition, environment and available options this week has asked the officials to fast track the Forest and other clearances for the controversial Gargai dam for additional supply of water to Mumbai. This is shocking on several counts.

Our study earlier showed that Mumbai does not need any additional dam including Gargai if it utilizes available local resources including rainfall, reuse of treated sewage, desalinization, demand side management, groundwater recharge, among other cost effective and less destructive options. The Chief Minister of his government has not bothered to respond to these concerns or options. In fact, when our study was published, even government officials in Mumbai had supported our conclusions.

Over the last about 4 years, very interesting events are playing out in India’s judiciary regarding the encroachments in Anasagar lake in Ajmer, Rajasthan.

The first order from the National Green Tribunal came to remove the encroachments from Anasagar lake in Dec 2021, reiterated in Aug 2023 as the encroachments were in violation of the environmental regulations and Wetland Rules of 2017. Apparently, the state government with investment of Rs 12 Cr was the biggest encroacher and the investment in the encroached land continued even while NGT order was awaiting implementation.