Designing Bhubaneswar: Gangua Nala at a glance

Introduction: The Bridge That Wasn’t Just a Bridge

I stood on the narrow bridge between Mani Tribhuvan and Royal Lagoon in Raghunathpur — a place most people drive past without thinking. Cars rolled over it, school vans idled beside it, and joggers crossed it with earphones in, never looking down. But I did.

Below me, water moved slow, dirty, uncelebrated. A polluted stream, covered with the failures of municipal bodies. To anyone passing, it looked like a random storm drain. Nearby area cluttered with piles of plastic and other stinking dead bodies of cows and dogs.

But I wasn’t there by accident. I had a question:

Does this small channel connect to something larger?

Does this water, quiet and ignored, belong to the living archive of Bhubaneswar’s forgotten natural system? Cities don’t die in a day. They fade silently, layer by layer starting from the places no one looks at closely. For Bhubaneswar, that silent, forgotten place is Gangua Nala. Ask any citizen about it, and you will hear: “Oh… that drain near Tankapani… that dirty canal…”. But if you dig deeper — into the soil, the maps, the memory of old Bhubaneswar — you discover something else: Gangua was never born a drain.

It was a river.

A river that once formed the natural southern moat of Ekamra Kshetra, fed the wetlands of the ancient city, protected the settlements, balanced floods, and nurtured the first agricultural belts. If Bhubaneswar is a planned capital, Gangua is the unplanned spine that everything quietly depends on.

And this episode is where we finally give it the attention it always deserved.

A historical trace- from river to drain

The Ancient Identity: Gandhabati / Kushabhadra Branch, it was seasonal, but it was never artificial. Archeological evidence points that the Gandhabati banks were home to settlements as early as the 4th century BCE, where Gangua provided water for irrigation, drinking and religious practices. Many of the city’s historic temples, including Mukteswar, Lingaraj, and Rajarani, were once directly linked to Gangua’s water system.

 In fact, modern city planner Otto Koenigsberger in 1948 explicitly used Gangua as a stormwater drain for the new capital: Bhubaneswar, its foundation was laid on April 13th, 1948.

During the Planning Era: 1950–1990, Its width reduced., Its flow slowed., Encroachment became normal.

The Rebranding: From Nadi to Nala.

Maps now call it a nala. Budgets treat it like a drain. But hydrologically, nothing changed —it still carries the stormwater of more than 60% of the city. Old regional hydrology maps and oral histories from the villages around Tankapani and Dhauli suggest that Gangua was once a natural drainage channel connected to the Daya–Kushabhadra system. As Bhubaneswar expanded: Natural wetlands were reclaimed, Village tanks were filled, Stormwater paths were interrupted, Concrete replaced soil, Gangua silently took the burden. Eventually, the river’s social identity changed.

The Geography of Flow

Before Bhubaneswar became a grid of roads and expanding apartments, it was shaped by the land — not the other way around. Water moved with gravity, following contour lines, feeding wetlands, tanks, and natural depressions. Older villages like Ghatikia, Raghunathpur, Patia and Chandrasekharpur were all positioned around water forms — not roads.

Gangua Nala existed long before planning documents named it. It was once part of the Kuakhai river system, acting as a spillway, a seasonal flood escape channel, and ecological corridor. The Mahanadi splits into several branches. One major branch becomes the Kuakhai River. Gangua Nala branches off from the Kuakhai, flowing southward and skirting the eastern edge of Bhubaneswar. This makes Gangua a secondary distributary of Mahanadi.

Gangua does not originate from Daya or Kusabhadra. After flowing for several kilometres, Gangua meets the Daya River just before the Daya moves toward Chilika. From there, the Daya eventually connects with the Kusabhadra system downstream near Dhauli–Balipatna regions.

So the hierarchy is:

Mahanadi → Kuakhai → Gangua → Daya → Kusabhadra (downstream linkage)

 Today, however, Gangua is mostly known as:

“That polluted drain south of the city.”

But hydrology ignores reputation. It remembers shape. And shape tells us something important:

Most of Bhubaneswar’s natural drainage eventually flows toward Gangua.

The Forgotten Spine

Maps of Bhubaneswar’s drainage network show something fascinating: a branching system — almost like lungs — draining the north, east, and western urban zones into a single channel. At the bottom of this network is Gangua. Every storm drain, culvert, nala and roadside canal is part of a hierarchy:

Local runoff ↓ Feeder drain / tributary ↓ Secondary drain ↓ Major drainage corridor ↓ Gangua Nala ↓ Kuakhai River

When a city grows, its water remembers everything. Gangua Nala—once a seasonal stream that carried the monsoon breath of the Kuakhai—has slowly become the most misunderstood, mishandled, yet structurally essential vein of Bhubaneswar. Anyone who looks at it today sees only a dark, clogged drain running through the eastern periphery of the city. But behind that murky surface lies the real story: a natural water system that was reshaped, confined, and finally choked by rapid urbanisation. If Bhubaneswar’s geography was a living textbook, Gangua Nala would be the chapter that explains how a city forgets its rivers while expanding into a ‘smart’ skyline.

The first problem begins with perception. Gangua is not a drain; it became a drain because the city treated it like one. What was once a clear, flowing channel collecting excess monsoon water from Chandaka, Khandagiri and the natural slopes of the city, is today the endpoint of unmonitored sewerage lines that discharge untreated water every hour. The pollution is not subtle—it is visible in floating garbage bags, remnants of household puja materials, discarded idols, plastic waste, animal carcasses, and the grey slurry released by apartments, industries, and small factories that operate on the edges of the drainage basin. Many of these buildings have Water Treatment Plants only on paper. Others have WTPs that exist physically but are non-functional, uncalibrated, unchecked and entirely mismanaged. The regulatory oversight is almost ceremonial. Approvals are handed out quickly; inspections rarely happen; wastewater management is not just loosely enforced but almost entirely ignored unless a major complaint arises.

The cumulative effect of this carelessness is catastrophic. Gangua Nala can no longer breathe. It does not carry water; it carries the burden of a city that refuses to grow responsibly. Even during the rains, when the nala should spread its natural floodplains, the water surges unpredictably because the channel is narrowed, encroached, and filled with debris. Bhubaneswar’s drainage masterplan always placed Gangua as a backbone for monsoon resilience. Instead, it has been converted into a dumping corridor.

This failure becomes even more evident when we revisit the government's ambitious announcement: turning Gangua into an inland waterway. It was a beautiful idea on paper—reviving the channel, deepening it, cleaning it, and transforming it into a navigable, green corridor that connects farmlands, peri-urban pockets, and the expanding eastern suburbs. But today, that vision feels distant, almost abandoned. An inland waterway requires consistent water quality, uninterrupted flow, reinforced embankments, ecological buffers, and a culture of zero-dumping. None of these conditions exist yet. The plan floated, gained media attention, and then gradually dissolved into administrative silence.

The Possibility of Restoration

The story doesn’t have to end as a lament. There is a practical and visionary way to restore Gangua—an approach that merges hydrology, ecology and urban design. I imagine a GBG corridor: Green–Blue–Green, a continuous linear system where two green belts protect and celebrate the central blue line of the nala. On both sides, dense vegetative buffers absorb pollutants, stabilize the embankments, and create ecological pockets for birds, insects and amphibians—reviving the micro-ecosystems that once thrived here. Between these green arms lies the blue artery—the rejuvenated nala—clean, aerated, and restored to a natural flow profile. Not a canal of concrete, but a breathing water body that belongs to the land.

To make the GBG corridor function, Bhubaneswar must separate its water logic. Rainwater cannot mix with sewage; yet today, they merge everywhere. Dedicated rainwater channels should be carved parallel to the main flow, feeding the nala only during the monsoons, not during household activities or commercial discharge. The city needs decentralized wastewater treatment units—small, community-level WTPs built near dense residential pockets and industrial clusters. These WTPs must be functional, audited, and maintained. Many cities around the world do this; Bhubaneswar can too, but only with political will and administrative discipline.

The industries and apartments that line the periphery of Gangua must be answerable. Zero-discharge policies cannot be optional. Every building must be required to not just have a treatment plant but maintain it, operate it, track it, and submit digital reports monthly. Violations must invite penalties—not symbolic ones but meaningful fines that reflect environmental damage. The city must be brave enough to enforce these rules, because rivers do not negotiate with us. When they collapse, cities suffer silently—through waterlogging, flooding, groundwater contamination and the slow death of green cover.

Restoring Gangua also means reimagining its role in Bhubaneswar’s identity. It can be a linear park, a cycling-walking greenway, a climate corridor that brings down urban heat, a waterscape that reconnects eastern Bhubaneswar with its natural heritage. The GBG corridor can become the city’s longest continuous public space, weaving ecology with accessibility. Stormwater can find its natural path again. The waterway plan—if revived with scientific grounding rather than political excitement—can even materialize over time as water quality improves.

Gangua Nala is not a forgotten stream; it is a mirror that shows us what Bhubaneswar is becoming. Whether it remains a polluted trench or transforms into a regenerative corridor depends entirely on the choices the city makes today. Urban design is not about buildings and flyovers alone. It is also about rivers, soils, air, drainage, and the invisible systems that make a city livable. Gangua, in its silence, has been carrying the weight of Bhubaneswar’s neglect for decades. Now it waits—perhaps impatiently—for the city to finally recognize its true place and give it the dignity of a river once again.

Vivid research for future reference

Gangua Nala Contamination

Research shows that Bhubaneswar’s Gangua Canal (a 23 km urban “nullah”) is the primary source of pollution to the Daya River[1]. The 1.2 million city population depends on these waters, yet Gangua carries untreated industrial and sewage waste. Water‐quality surveys report critically high BOD along Gangua – values of 1.8–39 mg/L (whereas a healthy river’s BOD should be <5 mg/L)[2] – and corresponding dips in dissolved oxygen. Other indicators likewise exceed safe standards: for example an Odisha PCB report found DO, BOD, COD and E. coli all “beyond permissible limits” in the Daya after Gangua’s inflow[3]. Downstream of Gangua the Daya’s coliform count jumps by orders of magnitude: ~61,300/100 mL at Manitri and ~74,900/100 mL at Kanti after the confluence[4], far above the 500/100 mL norm. This evidence underlines Gangua’s overwhelming contribution of organic and bacterial pollution to the river.

Cultural Waste and Activism

In addition to sewage, community practices have burdened Gangua. Residents note that idol immersions and puja waste (as in many Indian rivers) add to its pollutant load. In early 2025 environmental groups (e.g. Mahanadi Bachao, Gangua Bachao, Daya Surakhya Abhijan) issued a formal resolution: they demanded the government initiate urgent cleanup of the Daya and Gangua, and even argued Gangua should be restored to “river” status given its ecological role[5]. They pressed for scientific input and local oversight in the revival project, rather than a purely engineering approach. Crucially, they demanded an inquiry into why planned STPs along Gangua have not been completed and called for strict action against all polluters (industries, housing complexes, etc.) fouling the Gangua–Daya system[6].

Water Infrastructure and Treatment

The state has launched major infrastructure initiatives to improve Bhubaneswar’s water treatment. A new 130 MLD water‐treatment plant at Mundali (drawing from the Mahanadi) was approved in late 2022, with construction starting in early 2023 and a target completion by March 2025[7]. Meanwhile, Bhubaneswar’s sewerage master plan calls for several new STPs: for example, Meherpali (56 MLD), Bauaghai (28 MLD), Kochilaput (43.5 MLD), Pakhrapur (8.5 MLD) and a nearly complete plant at Rokat (48 MLD)[8]. In sum about 186.5 MLD of STP capacity is proposed (against roughly 130 MLD current demand)[9]. Once operational, these facilities should divert sewage out of natural drains like Gangua. (Citizen activists are watching closely, noting that any unfinished Gangua‐area STPs remain a critical gap[6].)

Government Coordination and Next Steps

Finally, officials have intensified oversight. In December 2025 a high‐level meeting chaired by the Urban Development Minister (attended by BMC Commissioner Usha Padhee and others) reviewed the Gangua Nala Improvement Project along with Nicco Park and overall storm‐water drains[10][11]. The ministers stressed an integrated approach – clearing encroachments, restoring riverbanks, upgrading public amenities and drainage in tandem – with strict timelines and quality checks[11]. This renewed government push, combined with persistent citizen pressure, represents a turning point: it aims to ensure Gangua’s revitalization and to stem its pollution of the Daya before the next monsoon.

Sources: Peer‐reviewed studies and reports on Daya/Gangua water quality[1][2][12]; local news and government releases detailing activism and projects[5][6][7][8][9][11].

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Citations

[1] Surface Water Quality Assessment, Prediction, and Modeling of the River Daya in Odisha

https://www.chijournal.org/Journals/PDF/C508

[2] fishtaxa.com

https://fishtaxa.com/index.php/FishTaxa/article/download/174/171/339

[3] [4] [12] journalijar.com

https://www.journalijar.com/uploads/2017/10/498_IJAR-20306.pdf

[5] [6] Make Daya river pollution-free, demand activists

https://www.newindianexpress.com/cities/bhubaneswar/2025/Feb/07/make-daya-river-pollution-free-demand-activists

[7]  Odisha Cabinet approves bid for 130 MLD water treatment plant for Bhubaneswar

https://odishatv.in/news/odisha/odisha-cabinet-approves-bid-for-130-mld-water-treatment-plant-for-bhubaneswar-196928

[8] [9] devalt.org

https://devalt.org/images/L2_ProjectPdfs/Understanding_Waterflows_In_Bhubaneshwar_HBF.pdf

[10] [11]  Odisha govt resolves to restore polluted Gangua canal

https://www.uniindia.com/news/east/development-odisha-gangua-nala/3668885.html

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