While the nationwide lockdown in 2020 was debilitating to the economy, it came as a respite to the environment, particularly to rivers. Studies by the Central Pollution Control Board & other non-profits confirm that there has been considerable improvement in water quality of major rivers during the lockdown. Here is a review.
In this story, we look at the impact of the COVID-19 lockdown on the water quality of major rivers. The reports by Center Pollution Control Board (CPCB) indicate improvements in terms of reduced organic pollution and increased saturation level for major rivers and significant improvement in the water quality of Yamuna and Ganga. Action Aid’s report highlights community experiences with changes in river water quality during the lockdown by registering an increase in domestic usage of river water, aquatic life, and water quality.
On 24 March 2020, the Government of India imposed a nationwide lockdown as a preventive measure against the spread of the COVID-19 pandemic. The lockdown was further extended in four different phases to 31 May 2020, and an unlock period thereafter. During the lockdown period, the movement of public transportation, commercial and industrial activities had been restricted strictly.
The lockdown led to economic loss, and at the same time, it came as a respite to the environment. Few rivers were able to rejuvenate naturally to some extent in view of no industrial wastewater discharge, non-operation of commercial centres, places of worship, washing and bathing activities, etc.
To access the quality of all major rivers in the country, Center Pollution Control Board (CPCB) conducted sampling in association with State Pollution Control Board (SPCB)/Pollution Control Committee (PCCs). A comparative assessment of water quality in 19 major rivers during pre-lockdown (March 2020) and during lockdown (April 2020) and a report titled Assessment of Impact of Lockdown on Water Quality of Major Rivers was subsequently published in September 2020.
The study was carried out with a view to:
- Study the impact of lockdown on water quality of major rivers due to restriction of activities in the country.
- Compare the water quality of major rivers during pre-lockdown (March 2020) and lockdown period (April 2020).
- Assess water quality of major rivers for compliance to the parameters prescribed under ‘Primary Water Quality Criteria for Outdoor Bathing’.
The analysis of collected samples revealed improvements in terms of reduced organic pollution and increased saturation level in case of few rivers. However, bacterial load continued to be predominant especially along with the urban centres due to continued flow of treated/partially treated sewage. Overall, a marginal improvement was observed in the water quality of the monitoring rivers.
Overall observations on 19 Major Rivers monitored during Pre-lockdown (March 2020) and Lockdown Period (April 2020) are highlighted below.
What about ‘Primary Water Quality Criteria for Outdoor Bathing’?
100% compliance: Four rivers viz., Baitarani, Mahanadi, Narmada and Pennar showed 100% compliance with the ‘Primary Water Quality Criteria for Outdoor Bathing’ during pre-lockdown and lockdown period. Cent percent compliance was observed during lockdown w.r.t ‘Primary Water Quality Criteria for Outdoor Bathing’ in case of 6 rivers (viz., river Baitarani, Brahmani, Brahmaputra, Mahanadi, Narmada and Pennar) which may be attributed to the availability of adequate infrastructure for management of sewage in the catchment of the respective river bodies and might have adequate dilution.
100% non-compliance: River Ghaggar failed to comply with the ‘Primary Water Quality Criteria for Outdoor Bathing’ during Pre-lockdown and lockdown period.
No change: Water quality of two rivers viz., Sabarmati (55.6 %) and Mahi (92.9 %) remains unchanged in terms of compliance to ‘Primary Water Quality Criteria for Outdoor Bathing’ during pre-lockdown and lockdown.
Improvement: Improvement in water quality w.r.t ‘Primary Water Quality Criteria for Outdoor Bathing’ was noticed in case of 7 rivers viz., Brahmani (increase in compliance to the bathing criteria limits from 85% to 100%), Brahmaputra (enhancement in compliance to the criteria limits from 87.5% to 100%), Cauvery (a marginal improvement from 90.5% to 96.97%), Godavari (increase in compliance from 65.8% to 78.4%), Krishna (improvement in compliance from 84.6% to 94.4%), Tapi (improved compliance from 77.8% to 87.5%) and Yamuna (increase in compliance from 42.8% to 66.67%).
Deterioration: Water quality has not improved during the lockdown period in case of five rivers viz., Beas (reduced from 100% to 95.45%), Chambal (reduced compliance to the criteria limits from 75% to 46.15%), Ganga (reduced compliance to the criteria limits from 64.6% to 46.2%), Sutlej (reduction in compliance from 87.1% to 78.3%) and Swarnarekha (reduction in compliance from 80% to 53.33%).
According to the report, improvement in water quality of few major rivers can be attributed to:
- Minimal industrial effluent discharges in view of the closure of almost all industries.
- No human activities involving the disposal of worshipped puja materials and garbage.
- No anthropogenic activities such as outdoor bathing, washing of clothes, vehicle washing and cattle washing, no pilgrimage activities, etc. during lockdown phase.
- Reduced cattle movement.
Exclusive studies on Yamuna and Ganga indicate improvement in water quality
The CPCB’s Report on Assessment of Impact of Lockdown on Water Quality of River Yamuna – Delhi Stretch, indicates that there is considerable improvement in water quality of river Yamuna (with respect to DO/Dissolved Oxygen, BOD/Biochemical Oxygen Demand and COD/Chemical Oxygen Demand) when compared with pre-lockdown and lockdown period
According to the report, post-lock down improvement in water quality can be attributed to:
- Release of freshwater from Wazirabad Barrage and availability of dilution in river Yamuna.
- No industrial effluent discharge (about 35.9 MLD) due to the lockdown
- Good penetration of solar radiation in the water body due to washing out of bottom sediments as well as settleable and colloidal form of pollutants in river Yamuna, and
- Human activity such as the throwing of Pooja materials, solid waste disposal, bathing, washing of clothes, etc. is minimized due to the lockdown.
Similarly, CPCB’s Report on Impact of Lockdown on Water Quality of River Ganga, indicates nationwide lockdown has resulted in an overall improvement in water quality of River Ganga especially with regards to increased Dissolved Oxygen (DO) and reduced nitrate concentration. This may primarily be attributed to the absence of industrial wastewater discharge, agricultural runoff, and increased freshwater flow. The reduction in Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) concentration was relatively less due to continuous discharge of domestic wastewater into the river.
Increase in community-perceived changes water quality, aquatic life, domestic usage of river water
Apart from understanding the river water quality vis-à-vis testing, another way to look at the impact of lockdown on river water quality is through experiences of communities living on the bank of rivers and dependent on the water source. ActionAid Association (India)’s a report titled River Ecology: An assessment of the impact of COVID-19 lockdown, highlights community experiences with changes in river water quality during the lockdown.
The study collected responses from 550 respondents in 10 river valleys across 10 major states, who are dependent on the river either directly or indirectly to understand the impact of lockdown on river ecology. This study presents information with the objective of getting people to reflect on the changes in quality of river water, changes in the presence and availability of aquatic species, changes in river ecology due to COVID-19 lockdown and in river water consumption patterns.
The study found that more than 70% of respondents expressed an increase in colour of the water indicating cleanness, around 20% said there is a decrease in water colour indicating dirtiness of water and less than 10% said that there is no change in colour. With respect to bad odour from river water due to pollution and other garbage, around 80% felt a decrease in bad odour, 10% felt an increase and 10% expressed no change.
More than 95% of respondents expressed a decrease in industrial pollution in river water and only less than 5% expressed that there is no change. On one hand, about 40% of respondents expressed a decrease in domestic waste and 60% expressed a decrease in hospital waste, on the other hand, around 30% of respondents expressed there has been no change in domestic waste and 20% expressed no change in disposal of hospital waste into the river water. However, this data varies from river to river as hospitals and urban setups vary.
Almost 100% of respondents expressed that there has been an increase in aquatic species in Mahanadi, Narmada, Ganga, Yamuna and Nagavali. A large majority reported increase of aquatic life in Krishna (75%), Kaveri (70%), Gandak (75%), Godavari (80%) and Gomati (78%) as well. People perceived that the increased presence of fish and other aquatic species is due to a decrease in water pollution. About 60% of respondents also shared that an increasing number of migratory birds were seen in the rivers during the lockdown period.
People use river water for different purposes starting from bathing to cleaning, washing and other purposes. The study found an increase in river water usage for bathing, cleaning, washing, etc. In case of Ganga, Godavari, Krishna and Kaveri, the pattern varied from 80% to 25% increase, while in case of Gandak, Narmada, Yamuna, Nagavali the increase was 100%. The study also found that there has been an increase in the use of river water for agriculture in Ganga by 100%, Godavari & Nagavali by 75% and Krishna & Gandak by 60% during the lockdown period.
Overall, the report points out visible changes perceived by dependent communities in the quality of river water due to COVID-19 lockdown. The communities attested to positive changes in water quality of the river, improved river biodiversity, increased fish population and visibility of new species. The ActionAid’s report highlighting community-perceived changes in water quality of major rivers in many ways corroborates the findings of Center Pollution Control Board (CPCB)’s reports, which reported improvements in the quality of water in major rivers across the country.