Pune’s proposed river rejuvenation project does not consider ecology, hydrogeology, and climate change, say experts

Image shows the bank of the Mula Mutha river in Pune with underconstructed buildings in the background
  • India’s Prime Minister Narendra Modi laid the foundation stone for Pune’s River Rejuvenation Project in March, announcing the commencement of the ambitious project that aims to redesign and reengineer a 44-kilometre stretch of the Mula, Mutha, and Mula-Mutha rivers in order to clean and beautify the river within city limits.
  • The idea for the project was first floated five years ago by the Pune Municipal Corporation (PMC). The Detailed Project Report (DPR) for the project has been compiled by HCP Design, Planning, and Management Pvt Ltd, the consultant hired for the project, who has previously worked on the Sabarmati Riverfront Development and the Central Vista Project.
  • While concerned citizens, environmentalists, and experts agree that the rivers need to be cleaned, they contend that the DPR takes a piecemeal and unscientific approach to river rejuvenation, and fails to take into account the current science on ecology, climate change and hydrogeology.

The Mula and Mutha rivers originate in the Western Ghats and flow towards each other meeting in Pune at Sangam Bridge, and then flow together towards the Bay of Bengal as the Mula-Mutha River. These rivers once considered the lifeline of Pune, now reek of pollution and degradation within the city limits.

The Pune Municipal Corporation (PMC), the city’s civic body, first announced its intention to beautify these rivers in 2016 and is now geared to start the execution of the Pune River Rejuvenation Project. The project will be implemented as a public-private partnership by the civic body.

The estimated cost of this project, approved in 2021, is Rs 4,727 crores (47.2 billion). The project is proposed to be completed in 11 phases over 10 years. The geographical area covered by the project area within the city is expected to be 10.4 kilometres of Mutha river, 22.2 kilometres of Mula river, and 11.8 kilometres of the Mula-Mutha river, and the five dams upstream and catchment areas of these rivers.

The project aims to address concerns of frequent flooding, discharge of untreated sewage, solid waste and debris dumping, and poor condition of the river bed and banks. For flood control, the project aims to remove obstructions in the flow of the river and add engineering interventions to the cross section of the river to channelise the banks. According to Mangesh Dighe, PMC’s Environment Officer, this project was conceptualised with a comprehensive approach to the improvement of Pune’s rivers.

However, a section of experts and citizen activists refute this assertion.

They say they are apprehensive about the project’s proposal to reclaim the rivers’ floodplains and riparian zones, noting it would worsen floods. And it fails to embrace streams. The rivers will instead benefit from cleaning and protection which is not the priority in the revival plan’s funding allocation. They warn that channelising the river banks will ruin the ecological balance of the river and reduce it to a mere channel that transports water, and unless the river is cleaned it cannot be rejuvenated.

With Pune being a saucer-shaped city, these changes to the topography of the river also heighten the risk of flooding and reduce the city’s carbon mitigation and climate change adaptation potential.

The Mula and Mutha rivers originate in the Western Ghats and flow towards each other, meeting in Pune at Sangam Bridge, and then flow together towards the Bay of Bengal as the Mula-Mutha River. Photo by Vivek Shenoy.

Flood protection noted as the first objective of proposed project

The proposed river rejuvenation project aims to contain the river water with embankments designed for flood protection, transforming the river’s banks into “a linear pot”, as explained by Ganesh Ahire, architect and urban planner with HCP Design, Planning, and Management Pvt Ltd., the consultants hired to draft the Detailed Project Report (DPR) for the project. The company has previously worked on the Sabarmati Riverfront Development and the Central Vista Project.

“When you pour water over flat land, it spreads everywhere, but when poured into a pot, it is contained. We are making a linear pot with edges that will ensure that the water does not overflow and spill out in the city,” shared Ahire, at an event organised by the Bharatiya Janata Party Infrastructure Cell to discuss the details of the project in Pune.

The DPR suggests flood protection measures in the form of removal of obstructions and proposes well-modulated embankments which provide a smooth flow of water due to straight embankment edges.

These measures are expected to increase the velocity of the river water and bring the red and blue lines down. But Aneeta Gokhale-Benninger, executive director of the Centre for Development Studies and Activities (CDSA) which is the local partner for HCP Design, says that though water will flow faster through a narrower width as opposed to a broader width, the river flowing between its natural banks is the domain of the river and must be held sacrosanct.

The DPR states that the floodplains and riparian zones of the river will be reclaimed. Such reclamation will exacerbate floods in the city, says Sarang Yadwadkar, city-based environmentalist and architect.

“The river cannot be contained in a linear pot as they envisage. Thinking logically, if you pour water into a saucer, it spreads across a wider surface area but the depth of the water is less. If you try to contain the water in a restricted channel its vertical dimension will be more because water requires a particular cross-sectional area to flow,” explained Yadwadkar.

“Removing obstructions will increase the velocity but they are going to construct barrages and additional ghats which will cause obstruction to the flow. Secondly, they are going to reduce the cross-sectional area of the river which will constrict the flow and strangulate the river,” he elaborated.

Read more: People power to clean up Pune river, bit by bit

The Maharashtra State Adaptation Action Plan on Climate Change prepared by The Energy Resources Institute in 2014 predicts that the impacts of climate change will reflect in changing rainfall patterns with fewer rainy days but an increase in the quantum of rainfall up to 37.5%. “Any projections that do not factor in the unprecedented changes in the climatic conditions are useless,” asserts Priyadarshini Karve, National Convenor of the Indian Network on Ethics and Climate Change (INECC).

Shatakshi Gawade, a city-based independent journalist who covered the Pune floods in 2019 says, “Dam management is part of flood management, and the riverfront development project does not consider this aspect at all. Flood control also requires that the streams throughout the city are clean and not encroached upon and have a clear path to reach the river. The proposed project focuses only on the riverfront, and does not have any provision for the management of streams.”

The river flow is choked at many places due to the accumulation of garbage and the growth of weeds. Photo by Vivek Shenoy.

“Hydraulic study in the DPR does not consider free catchment discharge”

Sarang Yadwadkar warns that calculations in the Hydrology and Hydraulics section of the DPR indicate that the flood levels in the city will increase with channelisation of the river banks. Another concern shared by Yadwadkar is that the hydraulic studies in the DPR are faulty because discharge from the free catchment area (area downstream of the dam but upstream of the city) amounting to over 1,000 cumecs has not been included in the study.

When asked for clarification on this point, Ganesh Ahire of HCP Design and Mangesh Dighe, of the PMC, said that the discharge from the entire catchment area has been considered in the hydraulic study. “When we say full catchment area, it is around 2,000 sq. km., which also includes the catchment of the upstream dams Mulshi, Pavana, Khadakwasla, etc. as well as the free catchment area of each river. The project boundary in the DPR shows the river stretch flowing through the city. However, for the purpose of hydrology and hydraulics, the project boundary is extended to the catchment area,” said Dighe.

On specific questions with regard to the inclusion of the free catchment area in the DPR, experts from the Irrigation Department are yet to respond with answers as to which parts of the studies in the DPR include these numbers.

Read more: Tracking rivers, the highways of plastic waste

“River rejuvenation must start with cleaning the river”

“As of now, except during the monsoons, the water flowing in the rivers within Pune is entirely untreated sewage. Walking on the river banks you can see methane bubbles in the water. The first priority of any river project should be to ensure 100% sewage treatment of the water,” said Priyadarshini Karve of INECC.

Studies have shown that polluted rivers emit more greenhouse gases, increasing their global warming potential up to ten times. In 2018, the Mula-Mutha river was found to be the second-most polluted river in the state by the Maharashtra Pollution Control Board.

Aneeta Gokhale-Benninger agrees that the river needs to be protected and cleaned. Initially opposing the project, Gokhale-Benninger and her colleagues at CDSA later worked with HCP Design to bring sustainable elements to the project. “Riparian zones and a functional river ecosystem will definitely regenerate ecology but the river’s self-cleaning mechanism cannot deal with the enormous volumes of toxic sewage, so river cleaning through the river rejuvenation project is essential,” she said.

Water hyacinth and untreated sewage choke the Mula River at COEP Boat Club. Photo by Vivek Shenoy
Water hyacinth and untreated sewage choke the Mula River at COEP Boat Club. Photo by Vivek Shenoy.

The proposed river rejuvenation project lists cleaning the river and making it pollution-free as one of its objectives, but the summary of project costs does not earmark any amount for river cleaning. Two new Sewage Treatment Plants (STPs) and tertiary sewage treatment facilities to treat the water have been proposed in the DPR, but expenditure for this will be planned when the detailed design engineering for each of the 11 stretches is taken up, Mangesh Dighe told Mongabay-India.

“We need to keep in mind the sewage treatment needs of the city a few decades from now,” asserts Karve, referring to the money earmarked for beautifying the river banks; she said it could be put to better use if it were redirected to supplement the Japan International Cooperation Agency (JICA) Project to set up 11 new STPs in the city.

“Ecological and groundwater aspects ignored”

“The soil, the river banks and the water flowing in the river have an interface. The riverfront development project is trying to separate water from its banks. When this happens, the marshy and rocky areas will become manicured landscapes and the diversity of species we find here will be reduced. The littoral zones with patches of riparian grasses, medicinal plants and fauna that need habitat diversity will be wiped out by the riverfront development,” shared Shailaja Deshpande, ecologist and director of Jeevitnadi, an NGO working towards river revival through citizens’ participation.

Deshpande is concerned that the zooplankton and phytoplankton found in these areas known to sequester carbon and form the base of the life chain and food pyramid will be adversely affected.

Maharashtra’s rivers have been carved out of basalt rock that has a geological history of 65 million years. Any alterations to this river’s history through straightening, widening and removing of meanders do not make sense, at least from a historical and geological heritage point of view, shared Himanshu Kulkarni, Executive Director of Advanced Center for Water Resources and Management.

Read more:  Long term rainfall patterns and flooding in Pune city

“Concretisation of the river channel also is unfair. To be fair, the presentations that I was an audience to about the river rejuvenation project assert that concrete will be used only in limited sections of the project. However, any project that changes the natural state of the river to an engineered state has hydrological ramifications, which may not have been considered,” he shared.

The PMC and HCP Design have stated that they are planning to incorporate live streams into the project. Mangesh Dighe told Mongabay-India, “When the excavation and de-silting work starts, we will come across these natural streams. Natural springs entering the river will be given a different treatment. Our natural embankments do not have solid walls which will block the water from coming in.”

Low lying bridges and pavements will be removed by the proposed river rejuvenation project. Photo by Vivek Shenoy
Low lying bridges and pavements will be removed by the proposed river rejuvenation project. Photo by Vivek Shenoy.

According to Sarang Yadwadkar, such treatment of natural streams is not possible without first mapping them. Every river has recharge zones (aquifers that travel from a hill and bring water into the river) and discharge zones (aquifers that recharge groundwater and wells by taking water away from the river). These need to be identified before devising a plan to conserve them.

Himanshu Kulkarni also expressed skepticism about how the relationship between the aquifers of Pune and the river will be incorporated into riverfront development since the DPR has no reference to groundwater as far as he knew. “Verbal assurances that groundwater will be incorporated do not inspire much confidence that this aspect will be incorporated in the project. The complex geometry and relationship between the aquifers and rivers in Pune cannot be glossed over. Has the hydrological study for the riverfront development project considered groundwater at all? And if not, why not?” he asked.


Banner image: A view of the COEP Boat Club on the bank of the Mula Mutha river. Photo by Vivek Shenoy.

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