The Inland Navigation Renaissance

India stands at a critical juncture in its infrastructural and economic trajectory. There is a renewed emphasis on inland water transport (IWT), reminiscent of the thrust on highways that the ‘Golden Quadrilateral’ project represented in the early 2000s. With more than 20,000 km of navigable waterways spanning 24 states, India possesses one of the world’s most extensive natural networks for inland navigation.^[1] However, this ongoing strategic shift toward waterways as a sustainable transport alternative needs to be carefully assessed to ensure that economic expansion remains aligned with long-term ecological sustainability.

The growing importance of inland navigation in national planning reflects broader global trade projections and India’s favourable physiography.^[2] Economically, IWT offers clear advantages: in 2017, transporting one tonne of cargo over one kilometre cost approximately INR2.28 by road, INR1.41 by rail, and only INR1.19 by inland waterway.^[3] Energy efficiency also follows a similar gradient. A single litre of fuel can move 127 tonnes of cargo one kilometre by inland waterway, while rail transport can carry 97 tonnes and road, 50 tonnes.^[4] Correspondingly, carbon dioxide emissions by IWT are 33.4 g/tkm (tonnes per km), as against 48.1 g/tkm by rail and 164 g/tkm by road transport—thus, waterborne transport’s emissions are roughly five times lower than those of road transport.^[5]

Yet, currently, IWT carries only 2-3 percent of India’s total freight. The National Logistics Policy and the Jal Marg Vikas Project (JMVP) aim to increase this share to 5 percent by 2030 and 10 percent by 2047.^[6] Achieving these targets could significantly ease India’s logistics burden, estimated at 13-14 percent of the country’s gross domestic product (GDP), while simultaneously advancing climate commitments under the Paris Agreement.

The National Waterways Act, 2016, provided a strong legislative foundation for expanding IWT, designating 111 rivers and canals as National Waterways and establishing a statutory framework for their systematic development.^[7] Among these, National Waterway 1 (NW-1) on the Ganga, and National Waterway 2 (NW-2) on the Brahmaputra, have emerged as the primary operational corridors. Supported by the World Bank, the JMVP is, for instance, transforming NW-1 into a multimodal transport corridor linking Haldia (in West Bengal), Sahibganj (in Jharkhand), and Varanasi (in eastern Uttar Pradesh), with an emphasis on ensuring year-round navigability and seamless integration with road and rail networks.

Overall, 29 National Waterways have been made partially operational (see Table 1).

Table 1. Operational National Waterways (as of May 2025)

	NW No.	Name
1	NW-1	Ganga-Bhagirathi-Hugli River System (Haldia-Allahabad)
2	NW-2	Brahmaputra River (Dhubri-Sadiya)
3	NW-3	West Coast Canal
4	NW-4	Krishna Godavari River Systems
5	NW-5	East Coast Canal and Matai River/Brahmani – Kharsua – Dhamra Rivers/Mahanadi Delta Rivers
6	NW-8	Alappuzha - Changanassery Canal
7	NW-9	Alappuzha-Kottayam – Athirampuzha Canal
8	NW-14	Baitarni River
9	NW-16	Barak River
10	NW-23	Budha Balanga
11	NW-31	Dhansiri / Chathe
12	NW-44	Ichamati River
13	NW-48	Jawai-Luni-Rann Of Kutch River
14	NW-53	Kalyan-Thane-Mumbai Waterway, Vasai Creek and Ulhas River
15	NW-64	Mahanadi River
16	NW-86	Rupnarayan River
17	NW-94	Sone River
18	NW-97	Sunderbans Waterway
19	NW-10	Amba River
20	NW-83	Rajpuri Creek
21	NW-85	Revadanda Creek-Kundalika River System
22	NW-91	Shastri River - Jaigad Creek System
23	NW-68	Mandovi River
24	NW-111	Zuari River
25	NW-73	Narmada River
26	NW-100	Tapi River
27	NW-27	Cumberjua River
28	NW-47	Jalangi River
29	NW-87	Sabarmati River

The longest of the waterways is NW-4, comprising the canal systems along the Coromandel coast and the Krishna-Godavari systems (see Table 2). Only the latter stretch, however, is operational, with four tourist jetties at Srisailam, Nagarjuna Sagar Dam, Polavaram, and Muktyala/Harishchandrapuram having been commissioned along River Krishna in Andhra Pradesh.^[8]

Table 2. India’s Longest Waterway - National Waterway 4 (NW-4)

Details of Waterway	Length (km)	States
Kakinada Canal (Kakinada to Rajahmundry)	50.00	Andhra Pradesh, Telangana, Karnataka, Tamil Nadu, Pondicherry, Chhattisgarh and Maharashtra
Godavari River (Bhadrachalam to Rajahmundry)	171.00
Eluru Canal (Rajahmundry to Vijayawada)	139.00
Krishna River (Wazirabad to Vijayawada)	157.00
Commamur Canal (Vijayawada to Peddaganjam)	113.00
North Buckingham Canal (Peddaganjam to Central Station of Chennai)	316.00
South Buckingham Canal (Central Station of Chennai to Marakanam)	110.00
Marakanam to Puducherry through Kaluvelly tank	22.00
Godavari River (Bhadrachalam-Nashik) Maharashtra (736.1km), Telangana (528km), Andhra Pradesh (6km) & Chhattisgarh (20km) (20 km common in Telangana - Chhattisgarh, 6 km in Telangana -A.P. and 62.5km	1,201.60
Krishna River (Wazirabad- Galagali) Karnataka (297.8km), Telangana (375.7km) & Andhra Pradesh	636.20
Total Length	2,915.80

Indeed, India’s IWT sector is still nascent. For instance, in China, the Yangtze River Economic Belt alone transported nearly 4 billion tonnes of cargo in 2024,^[9] almost 30 times the volume—145.5 million tonnes—that India did along all its waterways in 2024–25.^[10] Europe offers another relevant benchmark: the Rhine–Danube navigation network, including the canal that links them, demonstrates how multiple countries can jointly manage inland waterways while upholding stringent environmental regulations.^[11] Europe’s example underlines that efficient and high-capacity inland navigation can coexist with strong ecological safeguards when supported by coherent governance, harmonised regulations, and robust cross-border management frameworks.

In India, IWT does represent a major opportunity for low-carbon, energy-efficient freight transport. Realising its full potential will require moving beyond an infrastructure-led approach towards planning that is sensitive to riverine ecology. Future policy must incorporate cumulative impact assessments, participatory decision-making, and adaptive management practices to ensure that economic gains are pursued without compromising the long-term ecological resilience of river systems.

The Silent Stakeholders: River Dolphins in Indian Waterways

The Ganges River Dolphin (Platanista gangetica), India’s national aquatic animal, acts as a sentinel species in the waterways, signalling the ecological health of river ecosystems that sustain fisheries and human livelihoods. India holds over 80 percent of the global population of this endangered species.^[12]  Its slow reproductive rate, specialised echolocation-based behaviour, and sensitivity to turbidity and noise make it highly vulnerable to navigation-related disturbances.^[13] Nearly 90 percent of its range overlaps with the current or proposed national waterways (see Table 3).^[14]

Table 3. National Waterways Within the Distribution Range of the Ganges River Dolphin in India (Proposed and Existing).

NW number	River	Length of NW (km)	States	Operational?
1	River Ganga-Bhagirathi-Hugli Rivers (Prayagraj-Haldia)	1620	Uttar Pradesh, Bihar, Jharkhand, West Bengal	Yes
2	Brahmaputra River (Sadiya-Dhubri)	891	Assam	Yes
7	Ajay River	96	West Bengal	Yes
12	Assi River	5.5	Uttar Pradesh	Yes
16	Barak River	121	Assam	Yes
18	Beki River	73	Assam	Yes
19	Betwa River	68	Uttar Pradesh	Yes
24	Chambal River	60	Uttar Pradesh	Yes
29	Damodar River	135	West Bengal	No
30	Dihing River	114	Assam	Yes
31	Dhansiri River-Chathe River	110	Assam	No
32	Dikhu River	63	Assam	No
33	Doyans River	61	Assam	No
35	Dwarakeswar River	113	West Bengal	No
36	Dwarka River	121	West Bengal	No
37	Gandak River	300	Bihar and Uttar Pradesh	No
38	Gangadhar River	62	Assam and West Bengal	No
40	Ghaghara River	340	Bihar and Uttar Pradesh	No
42	Gomti River	518	Uttar Pradesh	No
44	Ichamati River	64	West Bengal	No
47	Jalangi River	131	West Bengal	No
57	Kopili River	46	Assam	No
58	Kosi River	236	Bihar	No
62	Lohit River	100	Assam	No
65	Mahananda River	81	West Bengal	No
81	Punpun River	35	Bihar	No
82	Puthimari River	72	Assam	No
86	Rupnarayan River	72	West Bengal	No
92	Shilabati River	26	West Bengal	No
94	Son River	160	Bihar	No
95	Subansiri River	111	Assam	No
97	Sunderbans Waterways	654	West Bengal	Yes
103	Tons River	73	Uttar Pradesh	No
108	Varuna River	53	Uttar Pradesh	No

Source: Government of India, National Waterways Act, 2016.

Modern inland navigation introduces a suite of ecological stressors that directly affect Ganges River Dolphins and their habitat. Channel deepening and periodic dredging modify riverbed geomorphology and elevate turbidity, while bank protection structures and training works interrupt natural hydrological processes and reduce floodplain connectivity. Increased vessel traffic generates high levels of underwater noise that can mask the dolphins’ echolocation signals, impair their foraging efficiency, and elevate the risk of vessel strikes. Additionally, accidental oil spills and leakage of chemicals from cargo vessels pose significant threats to water quality and aquatic life. Although the JMVP environmental assessments outline a range of mitigation measures, their implementation has been uneven and insufficient.^[15]

Without consistent monitoring and strong regulatory enforcement, the growing expansion of India’s inland water transport network risks placing the Ganges River Dolphin on a decline similar to that of China’s Yangtze River Dolphin, (Lipotes vexillifer), which became functionally extinct in 2006 following decades of unregulated river development.^[16] Conservation initiatives, such as Project Dolphin in India (2020), or the Global Declaration for River Dolphins (2023), and the Convention on the Conservation of Migratory Species (CMS) CoP-13 Concerted Action (2020) have enhanced policy visibility for the species.

Historical Perspective: Navigation and Ecology in Parallel Worlds

India’s inland waterways have undergone profound historical transformation—from thriving colonial trade arteries to neglected post-independence corridors (once road and rail transport became ubiquitous), and now to recipients of a renewed focus within national infrastructure policy. During the colonial era, extensive navigation networks, notably the steamer routes on the Ganga and Brahmaputra rivers, underpinned regional transport and commerce.^[17] Steam navigation connected hinterland settlements with ports such as Calcutta and Dibrugarh in the east, facilitating resource extraction, troop movement, and administrative control.^[18] Apart from natural rivers, India’s inland navigation framework also included manmade waterways such as the Buckingham Canal from Vijayawada to Chennai, and the canal system along the Coromandel Coast in the south. Once an important colonial transport route, the canals are now defunct as waterways due to siltation, encroachment, pollution, and fragmented management. Although incorporated within National Waterway 4, the canals are not yet operational for inland navigation (see Table 2).^[19]

After independence, the expansion of rail and road infrastructure precipitated a rapid decline in inland water transport. Limited investment, silting of channels, and competition from subsidised land transport rendered most river services economically unviable by the 1960s.^[20]  This prolonged period of low navigation inadvertently created the ecological “breathing space” for India’s river systems. Reduced vessel traffic lowered underwater noise and physical disturbances, enabling partial habitat recovery. It was during this lull in commercial navigation, particularly in the 1970s and 1980s, in which the initial systematic ecological research on the Ganges River Dolphin began.^[21]

The subsequent inclusion of the species in Schedule I of the Wildlife (Protection) Act 1972, along with the establishment of the National Chambal Sanctuary at the junction of Madhya Pradesh, Rajasthan, and Uttar Pradesh in 1979 followed by the Vikramshila Wildlife Sanctuary in Bihar in 1991, and since then many more, marked the institutional recognition of this emergent conservation landscape. Through the 1990s and early 2000s, the relative absence of intensive navigation coincided with modest population stabilisation in some river stretches.

However, this unplanned ecological respite unfolded without any systematic recording of baseline conditions. As India re-expands its IWT network under the National Waterways Act 2016^[22] and the JMVP, the absence of such historical baselines limits India’s ability to fully understand the ecological benefits that emerged during periods of reduced navigation. Some insights can still be drawn from the ecological studies of river dolphins and their habitat conducted during that period, but these provide only partial reference points. Had comprehensive baselines been documented, they would have offered invaluable guidance for current efforts. Understanding how earlier pauses in river traffic influenced aquatic biodiversity is essential to creating strategies that balance economic mobility with ecological resilience.

The Contemporary Elements of the Paradox

Infrastructure Interventions and Ecological Impacts

The resurgence of IWT in India, particularly through the JMVP on National Waterway 1 (NW-1) from Varanasi in Uttar Pradesh to Haldia in West Bengal, represents one of the largest river engineering undertakings in the country’s history. Designed to ensure a least available depth (LAD) of 2.5 to 3.0 metres year-round, the project entails extensive capital and maintenance dredging, spanning over 1,620 km of the Ganga River system.^[23] Dredging disrupts benthic habitats, increases turbidity, and alters sediment dynamics—processes that directly affect the ecological integrity of freshwater systems and the survival of sensitive aquatic fauna, including the Ganges River Dolphin.^[24] Already, ongoing environmental degradation, including overfishing and decline of critical habitats, is eroding riverine productivity.

River training works such as bandalling,^[a] spurs,^[b] and bank protection structures maintain navigable channels by constraining river flow. However, these interventions also fundamentally alter natural hydro-morphology, accelerate erosion in non-reinforced reaches, and disrupt lateral connectivity with floodplain wetlands.^[25] Terminal construction at Varanasi in Uttar Pradesh, Sahibganj in Jharkand, and Haldia in West Bengal has involved large-scale riverbed modification and localised pile-driving activities, producing high-intensity underwater noise and vibration that may have impaired the acoustic behaviour of dolphins and fishes.^[26],[27]

Maintaining fixed navigation channels conflicts with the natural behaviour of India’s monsoonal rivers, where seasonal changes drive sediment load, water flow and overall aquatic productivity. Trying to keep static depths in such highly dynamic systems comes with significant ecological costs, including the disruption of natural sediment movement, reduced connection between the river and its floodplains, and the loss of critical spawning and nursery habitats of fishes. In China’s Yangtze River, heavy channellisation, port expansion and constant underwater noise contributed to the extinction of the Yangtze River Dolphin and severe decline in the numbers of Yangtze finless porpoise (Neophocaena asiaeorientalis).^[28] India’s current inland water transport expansion shows similar patterns of river modification, and without adequate levels of precautionary regulation or ecological monitoring.

Vessel Operations: The Acoustic Threat

Inland navigation operations generate a continuous acoustic footprint that overlaps with the echolocation frequencies (20-180 kilohertz) used by Ganges River Dolphins for navigation, prey detection, and social communication.^[29] Propeller cavitation, hull vibration, engine operation and associated port activities contribute to chronic underwater noise pollution, reducing the dolphins’ foraging efficiency and inducing behavioural avoidance.^[30],[31] Studies have shown that vessel traffic can elevate ambient noise levels, effectively masking dolphin communication signals within critical ranges.^[32]

The risks are not confined to acoustic disturbances. Propeller strikes associated with increased vessel movement and navigation signalling have become a significant threat in high-traffic stretches. Approximately 5 percent of all reported Ganges River Dolphin mortalities in the Ganga at Patna are attributed to propeller strikes.^[33]  With night navigation being actively promoted under JMVP, these risks are further heightened, as reduced visibility and limited operator training in wildlife-sensitive zones increase the likelihood of collisions.

Despite these threats, India’s Inland Vessels Act (2021) lacks any reference to acoustic emission standards or mandatory noise assessments. In contrast, European inland waterway regimes, for instance, the Rhine and the Danube, require compliance with vessel noise certification, propeller design standards, and exclusion zones in ecologically sensitive stretches.^[34] The absence of analogous provisions in India’s framework constitutes a massive regulatory blind spot.

Policy and Regulatory Vacuum

Environmental governance surrounding inland navigation remains fragmented. The Environmental Impact Assessments (EIA) for waterway projects employ generic terrestrial templates, which do not include parameters relevant to riverine megafauna, such as underwater acoustic profiling, turbidity thresholds, impact on prey-base of dolphins, and other key aquatic species distribution mapping.

The Inland Waterways Authority of India (IWAI), under the Ministry of Ports, Shipping, and Waterways (MoPSW), established in 1985, operates with a mandate centred on improving navigational efficiency, and its statutory provisions do not explicitly extend to ecological management or wildlife protection.^[35] At the same time, the Ministry of Environment, Forest and Climate Change (MoEFCC), which oversees biodiversity conservation, has limited scope for continued oversight once statutory clearances are issued. This separation of mandates between MoPSW and MoEFCC can result in areas of regulatory overlap or ambiguity, at times leaving interventions without the level of integrated ecological review that such projects may require.

Further, India lacks a Strategic Environmental Assessment (SEA) mechanism to evaluate cumulative impacts across multiple waterways. Each navigation project is assessed in isolation, overlooking the basin-wide implications of hydro-morphological modifications. Additionally, no dolphin-specific pre- or post-construction monitoring is mandated, despite the species’ National Aquatic Animal status with “protection” under Schedule I of the Wildlife (Protection) Amendment Act, 2022. This stands in stark contrast to the Mekong and Rhine protocols, where multi-national SEAs and continuous biodiversity audits guide inland navigation development.^[36]

Data Gaps and Knowledge Deficits

Scientific understanding of riverine biodiversity responses to inland navigation remains very limited in India. Baseline population estimates for river dolphins on national waterways are outdated or spatially incomplete.^[37] Systematic monitoring, such as real-time acoustic tracking or Before–After–Control–Impact (BACI) designs, has yet to be institutionalised. While infrastructure funding for JMVP exceeds INR5,369 crore, research support for aquatic ecology remains a fraction of that amount, reflecting a severe asymmetry between development and conservation investment.^[38]

The lack of real-time monitoring systems, such as hydrophones or acoustic buoys, hinders detection of vessel-related disturbances. Data on sediment composition changes, water quality, and fish migration under navigation stressors remains unpublished or dispersed across consultancy reports. In contrast, the Rhine-Danube corridor, for example, employs coordinated hydroacoustic surveys and ecological indicators to track navigation impacts.^[39]

India’s research landscape suffers from institutional silos—academic, governmental, and industrial stakeholders often operating independently, resulting in fragmented and non-comparable data due to differences in data collection methodologies. Collaborative frameworks that couple navigation infrastructure with ecological baselining, similar to the Mekong River Commission’s Environmental Management Division, are absent.^[40] Addressing these deficits requires policy reform to embed biodiversity science within infrastructure planning from inception rather than as post-hoc compliance.

The Conservation Imperative: Why River Dolphins Matter

The extinction of the Yangtze River Dolphin in 2006 underscored how rapid industrialisation and unregulated navigation can annihilate a species once considered resilient.^[41] For India, which has the largest population of Ganges River Dolphins, this represents a warning, and ought to be seen as a profound ecological responsibility. As the last viable stronghold of a lineage that was once abundant in Southeast Asia, India’s stewardship of the Ganges River Dolphin could define its global credibility in freshwater biodiversity conservation.

Ecologically, the Ganges River Dolphin serves as a keystone species and apex predator in the riverine food web, regulating fish populations and maintaining ecosystem balance.^[42] Its presence signifies the health of complex trophic interactions and water quality dynamics within the Ganga-Brahmaputra-Meghna basin. Declining dolphin populations often correlate with deteriorating fish population, increasing pollution, and disrupted hydrological flows—indicators of systemic ecological distress. Thus, conserving the dolphin is synonymous with conserving the ecological integrity of Indian rivers.

The dolphin is also deeply embedded in India’s spiritual heritage and mythology. Regarded as the Sehchar (fellow) of the goddess Ganga, it embodies the sacred energy of the river itself. Its recognition as India’s National Aquatic Animal in 2010 further cemented its status as a living emblem of the nation’s aquatic heritage.^[43] Yet, beyond cultural reverence, its survival hinges on reconciling development imperatives with ecological ethics.

Healthy dolphin populations correspond with robust fisheries—an essential resource for millions of riparian communities.^[44] Moreover, emerging models of ecotourism centred around dolphin-watching through the Jalaj Dolphin Safari initiative of the National Mission for Clean Ganga (NMCG) across Uttar Pradesh, Bihar and West Bengal (and separately in Assam) demonstrate how conservation can align with local economic incentives, generating income while fostering stewardship.

From a climate resilience perspective, conserving river dolphins contributes to maintaining natural flow regimes, sediment connectivity, and riparian vegetation—all crucial components of climate-adaptive river ecosystems. Degraded rivers lose their capacity to buffer floods, recharge aquifers, and support temperature regulation, amplifying the vulnerability of both biodiversity and human populations. Protecting Ganges River Dolphins, therefore, extends beyond species conservation; it is a pathway to fortifying ecosystem resilience under intensifying climate variability.^[45]

India has already showcased conservation excellence through its success with Project Tiger—which combined scientific rigour, political will, and community participation. Applying a similar model to riverine systems, through science-based flow management, habitat restoration, and trans-sectoral coordination, could establish the country as a world leader in freshwater biodiversity conservation, particularly as it assumes a prominent role in global fora such as the Convention on Biological Diversity (CBD) Conference of the Parties (COP).

Potential Pathways

As IWT expands, it is imperative to establish scientifically informed guidelines for monitoring, mitigating, and managing navigation-related impacts on biodiversity. A robust framework should include systematic monitoring of navigation routes, vessel frequency, traffic density, and underwater noise in relation to dolphin distribution, population trends, and acoustic behaviour.^[46] Establishing baseline data on vessel strikes, fuel leaks, oil spills, and the discharge of toxic materials such as fly ash due to accidents, is equally essential. Context-specific mitigation measures, such as vessel speed regulation, route realignment, adoption of noise-reduction technologies, and strengthened emergency response mechanisms, must be identified and implemented to reduce ecological risks. Finally, an integrated management framework, supported by legal instruments and effective regulatory enforcement, will be critical to ensure monitoring protocols, and that mitigation measures are applied consistently and at scale.

To guide sustainable inland navigation practices, a few pointers based on comprehensive environmental, social, and financial impact assessments that carefully weigh and balance all associated perceived risks, are discussed in the following paragraphs:

Considerations While Constructing or Repairing Terminals and Ports

New terminals should be developed only in dolphin ‘cold spots’—river stretches where dolphin presence and habitat use are minimal—to reduce ecological disturbance.^[47] While building terminals, a comprehensive pre-project environmental impact assessment (EIA) must be undertaken to ensure minimal disturbance through careful planning. During terminal or port construction or repair work, the choice of foundation technique is critical. Conventional impact piling generates intense impulse noise harmful to dolphins and other aquatic organisms.^[48] Alternative foundation techniques, such as drilled or bored piles, screw piles, or cofferdam installation, should be adopted, as these generate significantly lower levels of underwater noise compared to percussive piling.^[49],[50] When piling is unavoidable, vibratory piling is preferable to impact piling because of its lower peak noise levels and reduced risk of behavioural disturbance.^[51]

Additional mitigation measures could include use of bubble curtains to attenuate underwater construction noise,^[52] and implementing a soft-start or ramp-up procedure, allowing dolphins to detect and vacate the construction zone before peak activity.^[53]

The timing of construction is equally important. For instance, in the lower Hugli (Hooghly) River (West Bengal, India), Ganges River Dolphins are predominantly restricted to low-tide periods. The intrusion of saline water with the advancing tidal bore displaces them upstream, confining them to the upper sections of the river. Noisy operations, therefore, should be scheduled during such periods as when dolphins are naturally absent from the lower stretch, minimising ecological risk.

Beyond direct noise mitigation, river terminal projects should incorporate long-term conservation actions: regular habitat restoration in adjacent river sections, awareness programmes, and the establishment of interpretation centres. Finally, in areas where dolphin populations are present, passive acoustic monitoring should be employed to track behavioural and acoustic responses, enabling adaptive management of construction activities in real time.^[54]

Dredging, especially capital dredging that removes virgin benthic soil and sand to deepen channels, inevitably impacts river ecosystems. Conducting Environmental Impact Assessments (EIA) is therefore essential to evaluate its effects in the context of other activities such as navigation and fisheries. For the Ganges River Dolphin, dredging can increase turbidity, disturb prey, alter flow regimes, and generate harmful noise.^[55] Therefore, dredging operations should be restricted to the non-breeding season from April to September, should avoid critical habitats, and use low-noise technologies, ensuring real-time monitoring of dolphin presence. These safeguards would allow essential navigation needs to be met while minimising risks to dolphins and maintaining ecological balance.

Considerations During Navigation

Speed Limits

Vessel speed and propeller rotation are key drivers of underwater noise. Higher speeds and fast-rotating, small-diameter propellers increase cavitation, producing broadband noise (4–80 kilohertz) that overlaps with the communication and echolocation range of river dolphins.^{[56],[57],[58]} This noise can mask dolphin signals, reducing communication ranges by up to 60–80 percent in busy waterways,^[59] and has been shown to elevate metabolic stress in Ganges River Dolphins.^[60] Reduced speed can lower broadband noise levels by about 6 decibels, while slow-turning, large-diameter propellers generate less cavitation.^[61]

Adopting vessel speed limits of 5–8 km/h (≈2.7–4.3 knots) in ferry routes and inland waterways overlapping with dolphin occurrence areas/hotspots can substantially reduce both collision risk and acoustic disturbance. Lower speeds not only reduce the severity of strikes but also increase reaction times for dolphins and vessel operators to avoid collisions.^{[62],[63],[64]}

Seasonal Coastal Currents as Alternative Transport Pathway

An underexplored opportunity in India’s transport planning is strategic use of coastal waterways by leveraging seasonal coastal currents. The East India Coastal Current (EICC) and West India Coastal Current (WICC) are strong, large-scale oceanographic systems that reverse direction approximately every six months in response to monsoonal wind forcing.^[65] These currents flow predominantly northward during one season and southward during the other, offering a natural physical mechanism that could potentially be harnessed to support energy-efficient coastal transport.^[66]

Exploiting these seasonal currents could support north–south coastal cargo movement, particularly for bulk and non-time-sensitive goods, thereby reducing reliance on intensive river dredging and channel modification. Coastal shipping has been widely recognised as a fuel-efficient and lower-emission transport mode compared to road and rail, with potential benefits for climate mitigation and reduced ecological pressure on riverine habitats that support endangered species such as dolphins.^[67]

However, practical limitations must be acknowledged. The strength and direction of coastal currents exhibit pronounced seasonal and interannual variability, and their effective use would be constrained by weather conditions, port infrastructure readiness, vessel design suitability, and navigational safety considerations.^[68] Operational feasibility would therefore require adaptive scheduling, current-aligned routing, real-time oceanographic forecasting, and seamless integration with coastal port logistics and regulatory frameworks.^[69]

A hybrid transport strategy that combines inland waterways with seasonally optimised coastal navigation could offer a more ecologically balanced alternative to continuous river channellisation. Integrating coastal current dynamics into national transport and maritime planning would diversify India’s waterborne transport portfolio while helping to alleviate cumulative ecological stress on river systems.^[70]

Habitat Restoration and Bypass Corridors

Restoring oxbows and secondary channels as alternative corridors for dolphins during large vessel passages offers additional safeguards. Oxbows have proven effective refugia in other river systems, such as the Tian-e-Zhou reserve in the Yangtze basin.^[71] In this context, the example of the British-built Buckingham Canal remains relevant as a historical demonstration of how canal-based bypass routes can ease navigation pressure in ecologically sensitive stretches. With appropriate ecological safeguards, the revitalisation of such canal systems could complement river-based transport while reducing disturbance to habitats critical for river dolphins. Integrating such restoration bypass-channel programmes into IWAI operations, alongside routine dredging, would strengthen habitat resilience. The identification of bypass channels should be collaborative, involving state forest departments, research institutes, community institutions and non-government organisations (NGOs), supported by survey data and GIS-based habitat mapping.

Capacity Building and Installing of Monitoring Systems

Training vessel operators is critical to improve awareness and reporting of dolphin sightings. A standardised mobile application could facilitate reporting and provide automated alerts in dolphin hotspots. Linking app compliance to operator licensing would ensure dolphin-safe practices. Additionally, there should be periodic River Health Assessments (RHAs) to understand the overall health of river ecosystems.

There are two approaches to presenting the health status of a river, drawing information on various components such as hydrology, geomorphology, water quality and biotic profile. One is to arrive at integrated indices for various components, and if possible, an overall index that reflects river health. The other is to present information in a comprehensive manner on various variables influencing and/or determining the status of various components. This kind of presentation is referred to as a ‘report card’ on river health. Some of the visual indicators could be embedded in the dolphin sighting app. It would also be beneficial to strengthen the capacity of the concerned ports and inland navigation entities to undertake RHAs in navigation channels, preferably on a seasonal basis, following the River Health and Water Quality—RHA Protocol developed by Indian Institute of Technology (IIT) Kanpur and World Wide Fund for Nature-India (WWF-India).^[72]

Communication, Tracking, and Incentives

Enhanced communication between vessels and port authorities, supported by GPS-based tracking and hotspot visualisation platforms, can further reduce collision risks. Additionally, port-led incentive schemes, such as eco-certification for biodiversity-friendly vessels, would promote conservation-friendly navigation practices.

Policy and Certification

In India, vessels operating under River Sea Vessel (RSV) and Coastal Vessel (CV) categories are required to obtain a Domestic Document of Compliance (DDOC), certifying adherence to safety and operational standards. However, the present DDOC framework does not integrate ecological safeguards or biodiversity considerations. Strengthening the DDOC to incorporate dolphin-friendly navigation requirements would allow India to align inland shipping safety with conservation priorities, in line with International Maritime Organisation (IMO) guidelines on minimising underwater noise and cetacean ship-strikes,^[73],[74] and national commitments to protect the Ganges River Dolphin.

Considerations During Development of Vessels

Vessel strikes are a major cause of mortality for Ganges River Dolphins, particularly in the lower Ganga basin.^[75] Collisions often occur due to masked echolocation caused by high vessel noise or suction effects from propeller operation.^[76] The use of propeller guards, such as Kort Nozzles, has been proposed to reduce these risks. These ducted propeller systems improve thrust efficiency at low speeds (<10 knots), create physical separation from hard substrates, and reduce injury risks to both aquatic life and propellers.^[77]

Reducing the acoustic footprint of inland navigation requires a gradual transition from petroleum-powered ferries to electric-powered vessels (e-ferries). Conventional engines generate high-intensity broadband noise, particularly within the 30–80 kilohertz range relevant to dolphin auditory sensitivity, while also contributing to water and air pollution.^[78] In contrast, e-ferries produce quieter propulsion and reduce emissions. Their adoption, however, calls for investment in battery storage, vessel range, and load capacity suited to riverine conditions, along with strategically located renewable-powered charging stations and local maintenance capacity. Pilot projects in Europe and East Asia have already demonstrated their potential for noise and emission reduction.^[79],[80] Such initiatives have already been initiated in the Sundarbans in the Ganga basin.^[81]

Additional noise-reduction strategies include improved propeller and hull design, as well as machinery noise control:^[82]

• Propeller and hull measures: Regular propeller maintenance, antifouling coatings, and designs suited to typical operating conditions; use of advanced propellers {High Skew, Contracted Loaded Tip (CLT), Kappel,  New Blade Section (NBS)}; hub caps and wake inflow devices; improved propeller–rudder interaction (e.g., twisted rudders, Costa bulbs); hull modifications for smoother water flow; and regular hull cleaning.
• Engine and machinery measures: Selection of low-noise equipment, vibration isolators, four-stroke engines, and alternative propulsion systems (diesel-electric, liquefied natural gas (LNG), combined gas and steam or COGAS) to minimise vibration and structure-borne noise. While most effective if installed in newly built vessels, many measures can be retrofitted to existing vessels.

Finally, integrating advanced vessel-tracking and communication systems is vital to reducing collision risk and acoustic disturbance. GPS, Automatic Identification System (AIS), and satellite monitoring allow real-time tracking, navigation optimisation, and enforcement of speed restrictions.^[83] Coupled with decision-support tools and ecological alerts, such systems can warn operators when entering dolphin hotspots, prompting speed reduction or rerouting. Similar approaches have been used for ship-strike mitigation in the case of North Atlantic Right Whales^[84] and could be adapted for the Ganga basin, enhancing both navigational safety and biodiversity conservation.

Conclusion: Toward Coexistence

India’s ambitious expansion of IWT offers the promise of low-cost, low-carbon freight movement, but it also presents a profound paradox when set against the needs of its endangered Ganges River Dolphin, which inhabits many of the same river stretches being developed and trained for inland navigation. While IWT is often heralded as a green alternative to road and rail, its infrastructure and vessel operations can inflict serious ecological costs, particularly in sensitive riverine ecosystems.

Dredging, channel modification, and increased vessel noise and traffic undermine key habitat parameters for Ganges River Dolphins and other critically endangered aquatic species. Consequently, the economic benefits of IWT collide directly with the conservation imperative of protecting an indicator species of river health.

This collision course mandates immediate policy reform, research prioritisation, and stakeholder dialogue. First, environmental assessments must incorporate river dolphin-specific acoustic, collision and hydro-morphology parameters rather than generic templates. Second, vessel noise emission norms and speed restrictions should be instituted, aligning with global standards. Third, robust monitoring frameworks (before-after-control-impact designs) must evaluate the ecological outcomes of IWT expansion. Finally, meaningful stakeholder engagement that includes fishing communities, industry, wildlife agencies and local government, is crucial to reconcile navigation goals with biodiversity protection.

If India acts decisively, embedding wildlife-compatible navigation into its strategy, it could become a global model for wildlife-compatible inland waterways. The window is limited, however: failing to act before irreversible impacts accrue may mean losing the opportunity to demonstrate that economic growth and ecological integrity can indeed go hand-in-hand.

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Mohd Shahnawaz Khan is a wildlife ecologist with over 16 years of experience in aquatic species conservation and currently serves as Lead, Aquatic Habitats & Species, for WWF-India’s Sundarbans Delta Programme.

Anamitra Anurag Danda is Senior Visiting Fellow with ORF’s Energy and Climate Change Programme.

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All views expressed in this publication are solely those of the authors, and do not represent the Observer Research Foundation, either in its entirety or its officials and personnel.

Endnotes

• Indian Economy
• Economics and Finance
• Developing and Emerging Economies
• India
• blue economy
• blue economy india
• blue highways
• ganges river dolphin
• inland water transport
• inland waterways and dolphin conservation
• iwt sector in india
• river dolphin conservation

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