The Netravati River is a west-flowing river in southwestern Karnataka, India, originating at Bangrabalige Valley in the Kudremukh range of the Western Ghats in Chikkamagaluru district at an elevation of approximately 1,000 meters above sea level.[1] It traverses roughly 103 kilometers through hilly terrain before reaching the coastal plains and discharging into the Arabian Sea near Mangalore, where it merges with the Gurupura River at its estuary.[2] The river drains a basin area of 3,657 square kilometers, predominantly within Dakshina Kannada district, supporting essential water needs for drinking, irrigation, and fisheries in urban centers like Mangalore and Bantwal.[2] Characterized by high rainfall in its catchment due to the monsoon influence on the Ghats, the Netravati remains largely undammed, preserving its natural flow but attracting proposals for diversion schemes—such as the Yettinahole project—to address water scarcity in drier regions, which have sparked environmental concerns over potential ecological disruption and biodiversity loss in this biodiversity hotspot.[1][2]
Geography
Origin and Course
The Netravati River originates in the Bangrabalige Valley at Yelaneeru Ghat within the Kudremukha range of the Western Ghats, located in Chikkamagaluru district, Karnataka, at an elevation of approximately 1,300 meters.[3]From its source, the river flows generally westward, navigating the rugged hilly terrain of the Western Ghats before transitioning to the coastal plains of Dakshina Kannada district. It passes near significant locations including the pilgrimage town of Dharmasthala and Bantwal, contributing to the region's hydrology across Chikkamagaluru and Dakshina Kannada districts.[3]The Netravati merges with the Kumaradhara River at Uppinangadi, after which it proceeds through Mangalore and empties into the Arabian Sea near Ullal, south of the city. The river's total length measures 103 kilometers from source to outfall, encompassing a drainage basin of 3,657 square kilometers.[3]
Tributaries and Basin
The drainage basin of the Netravati River spans approximately 3,657 square kilometers, primarily within the Dakshina Kannada district of Karnataka, India, with headwaters extending into the Western Ghats of Chikkamagaluru district.[2][4] The basin features steep gradients in its upper reaches, transitioning to broader alluvial plains downstream, supporting a humid tropical climate with high rainfall exceeding 3,000 millimeters annually in the ghats.[3] This physiography facilitates rapid runoff and sediment transport, contributing to the river's seasonal flow regime, with peak discharges during the monsoon from June to September.The Netravati's major tributaries originate in the surrounding hill ranges and join predominantly from the left bank, augmenting its discharge before it merges with the Gurupura River near the Arabian Sea estuary. The principal tributary, the Kumaradhara River, arises in the Pushpagiri Wildlife Sanctuary at an elevation of about 1,600 meters and flows approximately 60 kilometers before confluence with the Netravati near Uppinangadi village, providing significant freshwater input critical for downstream hydrology.[2][3]Other notable tributaries include:
Shishila River (also known as Kapila River), draining from the Shishila hills and contributing to the mid-basin flow;
Gundiya River (Gundiya Hole), sourcing from forested uplands and adding to sediment load;
Neriya River (Neriya Hole), a shorter stream from the ghats enhancing local recharge;
Mrithyunjaya River from Charmadi Hole, originating in the Charmadi range;
Aniyoor River and Somavathi River (also called Laila River), smaller left-bank streams from adjacent ridges.[4][3]
These tributaries collectively drain sub-catchments rich in lateritic soils and evergreen forests, influencing the Netravati's water quality and volume, though no major dams exist within the basin to date, preserving natural flow dynamics.[2]
Hydrological Features
The Netravati River basin encompasses approximately 3,657 km² within the Western Ghats of Karnataka, India, characterized by steep topography that facilitates rapid runoff from heavy orographic precipitation. Annual rainfall in the basin ranges from 2,002 mm to 5,277 mm, with over 90% occurring during the southwest monsoon period from June to September, leading to a highly seasonal hydrological regime dominated by intense, short-duration events.[2][5] This precipitation pattern results in high surface runoff, with the river exhibiting flashy hydrographs where baseflow is minimal outside monsoon months, and peak flows can surge dramatically due to the basin's low infiltration capacity in forested and lateritic soils.[6]Average annual discharge for the Netravati-Gurupur combined system at the estuary measures about 388 m³/s, equivalent to roughly 388 TMC of annual runoff volume, reflecting efficient water yield from the humid tropical climate.[7] Flows vary widely, from minimums of approximately 9.6 m³/s in dry periods to maxima exceeding 1,800 m³/s during monsoonal peaks, with gauging data from sites like Bantwal indicating sensitivity to upstream land use changes that have historically increased discharge by about 7.88% between 1979 and 2012.[8][9] The Central Water Commission monitors water levels at key stations, underscoring the river's role in regional flood dynamics, where annual peak daily flows average around 4,175 m³/s over multi-decadal records, though trends show variability influenced by climate and vegetation cover.Water quality in hydrological terms fluctuates with discharge regimes, exhibiting fair to excellent conditions pre- and post-monsoon due to lower pollutant concentrations relative to flow volumes, but marginal status during high-flow monsoon periods from dilution of effluents alongside elevated suspended sediments.[10] Indices such as the Water Quality Index (WQI) for the river range from 33.21 (excellent) to 298.66 (very poor), correlating with anthropogenic inputs in low-flow seasons, while heavy metal levels remain under ongoing environmental monitoring to assess long-term basin health.[11][12]
Ecology and Biodiversity
Flora and Fauna
The Netravati River basin, situated within the Western Ghatsbiodiversity hotspot, features riparian vegetation dominated by angiosperm species in its upper forested reaches, including evergreen trees vital for watershed stability and ecological functions such as soil retention and water regulation.[13] Endemic and threatened plant species documented in the basin include Actinodaphne malabarica, Aglaia canarensis, and Aglaia lawii, reflecting the region's high floristic endemism amid pressures from habitat alteration.[14] In the lower estuarine zones, mangrove forests prevail, comprising low-diversity assemblages of 30-40 dominant higher plant species that buffer against coastal erosion and heavy metal accumulation before discharge into the Arabian Sea.[15]Aquatic fauna in the Netravati includes endemic cyprinid fishes such as Garra nethravathiensis, restricted to the river's freshwater segments in Karnataka, and Mesonoemacheilus petrubanarescui, type-localized near Dharmasthala.[16] The Netravati-Gurupura estuarine system supports diverse finfish assemblages, with ichthyofaunal surveys recording seasonal diversity indices varying by station and monsoon influences, alongside penaeid prawns comprising eight species that form a key component of local fisheries.[17][18] Estuarine phytoplankton communities exhibit succession patterns driven by tidal and nutrient dynamics, underpinning primary productivity that sustains higher trophic levels, though vulnerable to climatic shifts affecting endangered taxa with limited distributions.[19] Terrestrial and riparian fauna associated with the basin encompass bird species typical of Ghats habitats, including endemics observed in forested corridors, while broader basin wildlife features large mammals in upland forests, though riverine-specific populations face fragmentation risks.
Ecosystem Services
The Netravati River basin supports critical ecosystem services, including habitat provision for diverse riparian and aquatic species within its forested Western Ghats catchment. Designated as one of 30 global biodiversity hotspots under international conservation initiatives, the basin's pristine primary evergreen forests in the upper reaches maintain high floristic diversity and deliver supporting services such as nutrient cycling and soil stabilization, essential for sustaining the river's hydrological integrity.[20][13]Phytoplankton communities in the river, dominated by Chlorophyta (31 genera) and Cyanophyta (16 genera), function as primary producers, underpinning food webs that extend to higher trophic levels like zooplankton and fish. Seasonal abundance fluctuates between 1.35 million and 10.8 million cells per cubic meter, with Chlorophyta peaking in pre-monsoon periods and Cyanophyta in monsoon and post-monsoon phases, thereby regulating biogeochemical cycles of carbon, nitrogen, and phosphorus while indicating overall ecosystem health responsive to nutrient inputs.[21]Regulating services include water flow moderation and flood risk reduction through the river's consistent discharge from perennial Ghats sources, alongside estuary dynamics that buffer physicochemical variations to sustain transitional habitats. These functions, however, face pressures from anthropogenic activities, as evidenced by hydrochemical assessments linking river health to human well-being via integrated indices like the Happy River Index.[10][22]
Economic Importance
Agriculture and Irrigation
The Netravati River serves as a primary water source for irrigation in its basin, spanning Dakshina Kannada and parts of Chikkamagaluru districts in Karnataka, supporting agriculture during the non-monsoon period when rainfall is insufficient.[23] Approximately 35,000 hectares of paddy fields are irrigated by the river, benefiting around 700,000 farmers who rely on its seasonal flows for cultivation.[20]Key crops grown in the irrigated areas include paddy as the staple, alongside cash crops such as coconut, areca nut, rubber, cashew, and various vegetables, which thrive on the alluvial soils enriched by river sediments.[11] These agricultural activities contribute significantly to local livelihoods, with the river's consistent discharge enabling multiple cropping cycles in the coastal lowlands.[23]Irrigation infrastructure remains limited, with no major dams on the main stem to avoid ecological disruption in this biodiversity hotspot; instead, minor lift irrigation schemes, such as the Balthila Lift Irrigation Project, draw water from downstream barrages like Shamboor for localized distribution via canals and percolation tanks.[24] Proposed inter-basin diversions, including the Netravati-Hemavati link, aim to transfer surplus monsoon flows (estimated at 188 million cubic meters) to drought-prone areas for additional irrigation of 33,813 hectares, though implementation faces environmental opposition.[25] Riverbank protection works by the Minor Irrigation Department, spanning 1.5 km near Jalligudde, help sustain irrigable land by mitigating erosion and saltwater intrusion.[26]
Fisheries and Aquaculture
The Netravati River and its estuary host a notable prawnfishery, dominated by penaeid species including Penaeus indicus, P. monodon, Metapenaeus dobsoni, M. moyebi, M. monoceros, M. affinis, P. semisulcatus, and Parapenaeopsis stylifera, alongside the sergestid Acetes spp. and caridians such as Macrobrachium rosenbergii, M. idae, and M. idella.[18] Among these, P. indicus, P. monodon, M. dobsoni, M. moyebi, and M. monoceros constitute the most common catches, with seasonal peaks in abundance; for instance, M. dobsoni shows high recruitment from January and June to September, while P. indicus peaks in May, June, and December.[18] Commercial harvesting employs mini-otter trawls (accounting for 60-67% of catches), cast nets, and shore seines, yielding recorded prawn landings of 5.28 tonnes in 1981 and 14.37 tonnes in 1982 within the Netravati-Gurupur estuary.[18]Finfish diversity in the estuarine system supports additional capture fisheries, with studies documenting varying species richness across stations and seasons, influenced by factors like salinity and tidal mixing.[17] Inland fisheries in the river's creeks are intensive, contributing to Karnataka's broader freshwater production, though specific catch statistics for the Netravati basin remain limited in available data.[27]Aquaculture efforts, particularly cage farming, have emerged along the river, focusing on species like pompano (Trachinotus spp.) and mussels, with harvests timed before the monsoon to align with bans on deep-sea fishing.[28] Individual ventures involve investments up to ₹12 lakh, but operations face severe risks from pollution, as evidenced by mass fish deaths in pisciculture cages in February 2023, attributed to industrial effluents discharged into the river.[29][28] These incidents highlight vulnerabilities in river-based aquaculture, potentially limiting expansion despite the estuary's role as a nursery for juvenile fishes.[10]
Water Supply for Urban and Industrial Use
The Netravati River serves as the primary source of drinking water for Mangaluru city and surrounding areas in Dakshina Kannada district, Karnataka, through the Nethravathi River Water Supply Scheme. This scheme draws water from the river via the Thumbe vented dam, located approximately 20 km upstream from Mangaluru, which stores and regulates flow for distribution to urban centers including Mangaluru, Ullal, and Mulki. The dam maintains a storage height of up to 6 meters during adequate inflow periods, supporting a population of around 0.8 million with treated surface water predominantly sourced from the river.[30][31][32]Daily water demand under the scheme includes approximately 204.66 million liters per day (MLD) allocated for domestic and drinking purposes in Mangaluru, supplemented by reservoirs and check dams along the river and its tributaries to capture surplus flow at elevations above 300 meters. Additional vented dams and ancillaries, totaling 38 reservoirs in the basin, facilitate storage and conveyance, ensuring supply stability despite seasonal variations in river inflow. Untreated sewage inflows pose ongoing challenges to source water quality, yet the river remains the backbone of urban potable water provision for multiple taluks.[8][20][33]Industrial water usage from the Netravati is comparatively limited, accounting for about 27.24 MLD within the broader Dakshina Kannada supply framework, primarily supporting local manufacturing and port-related activities in Mangaluru. This allocation draws from the same riverine infrastructure as urban supply, with treatment focused on basic potability rather than specialized industrial standards. Regional industries, including those in oil refining and shipping at New Mangalore Port, rely on river-extracted water, though exact volumes tied solely to Netravati sources remain modest relative to agricultural withdrawals of 579.78 MLD.[8]
Cultural and Historical Significance
Religious and Mythological Role
The Netravati River, known locally as Nethravathi, is regarded as a sacred waterway in Hindu tradition, particularly within the Dakshina Kannada district of Karnataka, where it supports pilgrimage activities and ritual practices. Flowing through the renowned temple town of Dharmasthala—home to the Manjunatha Temple dedicated to Shiva—the river integrates into devotional routines, with its waters symbolizing purity and divine benevolence.[34]Mythologically, the river's genesis is linked to Vishnu's Varaha avatar in regional lore, as chronicled in the 16th-century text Theertha Prabandha by saint Vadiraja. In this account, the earth, submerged by primordial floods, was lifted to safety by Varaha; in a state of relieved bliss and gratitude, the land shed tears that coalesced into the Nethravathi, embodying themes of cosmic rescue and terrestrial renewal.[34] The river's name, derived from the Sanskrit "netra" (eye), aligns with this narrative of tear-born origin, underscoring its symbolic role in purification and spiritual catharsis.Devotees frequent the river for holy immersions, especially near Dharmasthala and its confluence with the Kumaradhara River at Uppinangady, attributing therapeutic and sin-cleansing properties to its flow—a common motif in Hindu reverence for rivers as life-sustaining and divinely infused entities. Sites along the banks, such as those featuring natural Shiva lingas, further embed the Netravati in Shaivite worship, drawing pilgrims seeking darshan and ritual ablutions.[34]
Historical Human Settlements and Utilization
The Netravati River has supported human settlements in the Tulu Nadu region since antiquity, with early concentrations along its estuarine valleys near present-day Mangalore. Archaeological and historical evidence indicates that the Alupa dynasty established initial bases such as Alupe (near Ullal) and Alake (near Bikarnakatte), dating to approximately 300 BCE–500 CE, leveraging the river's ancient course for strategic positioning.[35] These sites functioned as administrative and trade hubs, with the river providing navigable access to the Arabian Sea.[35]Geological shifts, including southward drift of the Netravati's channel by about 1 km between 500 BCE and 500 CE, prompted adaptations in settlement patterns, such as relocation to areas like Kudroli and later Barkur upstream.[35] The Alupas, ruling prominently from the 8th to 14th centuries CE, capitalized on the river's proximity for their capitals at Mangalore and Barkur, where it intersected with fertile lowlands suitable for agrarian communities.[36] Ports like Aluva-kheda in the Maroli-Alupe estuary, referenced in 7th-century CE texts such as the Prapancha Hridaya, underscore the river's role in fostering coastal polities.[35]Utilization of the Netravati historically centered on fluvial transport and commerce, enabling the export of hinterland products including spices, timber, and food grains via estuarine ports to maritime networks extending to the Roman Empire by the 1st century BCE–CE.[37] Mangalore, on the river's north bank, developed as a key entrepôt, with the Netravati facilitating connectivity to forested uplands rich in exportable goods.[37] Agricultural exploitation in the river valley supported local economies under dynastic rule, though systematic irrigation predated modern interventions and relied on seasonal inundation for rice and other crops in the alluvial plains.[38] By the 10th century CE, under Alupa king Kundavarma, the river's banks hosted significant urban centers like Mangalore, integrating settlement growth with riverine resource use.[39]
Infrastructure and Water Management
Existing Dams and Barrages
The Netravati River hosts several vented dams and barrages, which are low-height structures designed primarily for augmenting surface water storage for urban supply, irrigation, and minor hydropower, rather than large-scale impoundment. These facilities, often featuring automated vents to facilitate fish migration and flood passage, have proliferated since the 1990s, contributing to increased river fragmentation as noted in hydrological studies. No major multi-purpose reservoirs exist in the basin, reflecting the river's steep gradient and ecological sensitivities in the Western Ghats.[2][40]The Thumbe Vented Dam, located approximately 20 km upstream from Mangalore near Thumbe village in Bantwal taluk, Dakshina Kannada district, serves as the primary water source for Mangaluru city's drinking supply. Constructed to replace an older anicut, it spans 343.5 meters with 30 automated radial gates and a height of about 4 meters (13 feet) above the riverbed, enabling storage for pumping and treatment. Completed in phases around 2002-2003 with expansions, it maintains a full reservoir level of around 6 meters, supporting daily abstraction of up to 135 million liters, though levels fluctuate seasonally, dipping below 6 meters during dry periods.[31][41][42]Upstream of Thumbe lies the AMR Vented Dam (also referred to as AMR Barrage), operated by AMR Power Private Limited near Bantwal, which stores water for release during shortages to downstream facilities like Thumbe. This structure, with a reservoir depth reaching up to 18.6 meters at full capacity, facilitates controlled flows to prevent rationing in urban areas, as demonstrated in 2024 when releases filled Thumbe to 5.63 meters. It integrates minor hydropower generation alongside storage.[43]Other notable structures include the Jakribettu Barrage near Bantwal, which began impounding water in early 2025 to support local irrigation and supply, benefiting downstream areas including Mangaluru. The Biliyoor Vented Dam-cum-Bridge in Bantwal taluk, with construction initiated around 2020, creates backwaters for seasonal storage and flood mitigation, enhancing local water availability during monsoons. Additional smaller vented dams, such as those at Nidgal and Gilikapu, operate in series within the basin to optimize multi-reservoir yields for irrigation and rural needs, harvesting monsoon surplus estimated at over 1,240 TMC annually.[44][45][46][8]
Diversion Projects Including Yettinahole
The Yettinahole Integrated Drinking Water Supply Project constitutes the primary diversion initiative linked to the Netravati Riverbasin, targeting surplus monsoon runoff from its tributaries to alleviate water scarcity in eastern Karnataka districts.[47] The scheme diverts approximately 24.01 thousand million cubic feet (TMC) of water annually from four west-flowing streams—Yettinahole, Kadumanehole, Kerihole, and Hongadahalla—during the period from mid-June to November, when flows exceed downstream requirements.[47][48] This water is lifted via pumping stations and conveyed eastward through pipelines and canals, with Stage 1 transporting it 132 km to the Vani Vilas Sagar reservoir in Chitradurga district for distribution to initial beneficiary areas.[47]Administrative approval for the project was granted by the Karnataka government on February 17, 2014, at an estimated cost of Rs. 12,912.36 crore, encompassing the construction of eight small weirs and reservoirs (two each on Yettinahole and Kadumanehole, and one each on Kerihole, Hongadahalla, and two additional sites), pump houses, and extensive pipeline networks.[49][50] Stage 1, focusing on supply to Kolar and Chikkaballapur districts, was inaugurated on September 6, 2024, by Chief MinisterSiddaramaiah, with water delivery anticipated by November 2026 and full completion targeted for March 31, 2027.[47][51] Stage 2 will extend infrastructure 140 km further to Tumakuru, incorporating additional lifting and distribution systems.[47]The project is designed to benefit around 75 lakh people across seven districts—Kolar, Chikkaballapur, Bengaluru Rural, Ramanagara, Tumakuru, Hassan, and Chikkamagaluru—by filling 527 tanks and supplying potable water to 6,657 villages and 38 towns.[47] It evolved as a scaled-down alternative to the broader Netravati River Diversion Project, initially conceptualized in the 1970s following recommendations from the G.S. Paramashivaiah committee and revisited in subsequent decades, but reframed to emphasize tributary-specific extractions to minimize basin-wide flow alterations.[52] Proponents assert that diversions occur solely from monsoon surplus, preserving dry-season yields for coastal ecosystems and agriculture in the Netravati's lower reaches.[53] No other major diversion projects directly targeting the Netravati main stem have advanced beyond planning stages as of 2025.[54]
Controversies and Impacts
Environmental and Ecological Concerns
The Netravati River experiences pollution primarily from untreated municipal sewage, industrial discharges, and agricultural runoff containing pesticides from surrounding plantations, contaminating water and sediments along a 50 km stretch from Uppinangadi to Mangaluru.[20][55][56]Heavy metals such as lead in sediments pose a significant risk to aquatic life, with concentrations indicating potential bioaccumulation in the food chain.[12] Inspections in April 2025 documented ongoing inflows of polluted water and solid waste, exacerbating degradation of this key drinking water source for Dakshina Kannada district.[57]Hydrological alterations from dams have intensified ecological fragmentation, with a sharp increase in longitudinal discontinuity after 2010 attributable to five new structures that disrupt fish migration and habitat connectivity.[58][40] Declining sediment loads, measured at 19.65 kt yr⁻¹ in the Netravati, result from such impoundments combined with upstream land-use changes, altering downstream geomorphology and estuarine habitats.[59]Proposed water diversions, including elements linked to the Yettinahole project, threaten reduced base flows that could desiccate wetlands, impair fisheries dependent on consistent inflows, and degrade Western Ghats biodiversity.[60][61] Biologists have deemed these diversions unscientific, citing unquantified risks to flora, fauna, and regional hydrology without full ecological assessment.[62]Additional pressures include illegal sand mining exceeding regulatory limits, which destabilizes riverbanks and accelerates erosion, and laterite quarrying in the basin that contributes to habitat loss and siltation.[59][63]Urban expansion has amplified runoff and soil washout, with land-use intensification linked to heightened sediment yields and nutrient loading in the Netravati-Gurupur estuary.[64][10] The 2024 Netravati Waterfront Promenade project has drawn scrutiny for alleged Coastal Regulation Zone violations, potentially worsening shoreline ecology.[65]
Socioeconomic Debates and Protests
The Yettinahole Integrated Drinking Water Project, involving diversion of approximately 24.5 TMC (thousand million cubic feet) of water from Yettinahole and six other streams in the Western Ghats—flows that contribute to the Netravati basin—has ignited debates over inter-regional water equity versus localized economic dependencies. Opponents in coastal Karnataka districts, including farmers in Dakshina Kannada who rely on the river for irrigating arecanut plantations and paddy fields supporting over 50,000 households, argue that reduced freshwater inflows would salinize estuaries, disrupt fishbreeding cycles, and diminish catches by 30-50% for inland and marine fishermen, whose annual earnings exceed ₹500 crore from Netravati-dependent fisheries.[61][66] Urban stakeholders in Mangaluru, where the Netravati supplies 70% of municipal water needs for 1.2 million residents and industries like ports and food processing, warn of heightened rationing, groundwater depletion, and escalated treatment costs, potentially straining a regional economy valued at ₹1.5 lakhcrore annually.[60][67]These socioeconomic contentions have manifested in sustained protests since 2011, when initial diversion proposals surfaced, escalating with the project's foundation stone laying on March 3, 2014, amid demonstrations by local groups decrying livelihood threats.[68] Key actions include a September 15, 2015, highway blockade on National Highway 66 by farmers, students, and activists, halting traffic for hours to demand scrapping; a September 19, 2015, march in Mangaluru drawing thousands of students who vowed intensified resistance; and December 30, 2014, dharnas by the Yettinahole Yojane Virodhi Samiti in Sakleshpur against upstream abstractions harming downstream users.[69][70][71]Government advocates maintain the diversions tap underutilized surplus—up to 400 TMCFT annually wasted to the sea— to irrigate 55,000 hectares and supply 46 lakh people across seven drought-hit taluks, fostering economic growth in arid zones through enhanced agriculture and reduced migration, without exceeding 10% of basin yield based on hydrological assessments.[68] Critics, including economists and NITK experts, counter that such projections overlook cumulative drawdowns from climate variability and existing abstractions, rendering the scheme economically unviable with benefit-cost ratios below 1 amid high construction costs exceeding ₹10,000 crore and negligible returns for coastal stakeholders.[72][67] Protests continued into 2024, with activists labeling the September 6 push for 2027 completion a politically motivated diversion from viability scrutiny, underscoring persistent divides between upstream beneficiaries and basin dependents.[73][74]
Government Responses and Project Benefits
The Karnataka government has promoted the Yettinahole Integrated Drinking Water Project as a critical intervention to address chronic water scarcity in drought-prone districts, emphasizing its role in supplying potable water to underserved regions. The project aims to divert approximately 24.01 thousand million cubic feet (TMC) of water from Yettinahole and associated streams in the Western Ghats, channeling it through a 300-kilometer pipelinenetwork with multiple pumping stations to six districts: Chikkaballapur, Kolar, Tumakuru, Ramanagara, Bengaluru Rural, and Chitradurga. Upon full implementation, it is projected to benefit 27 taluks and provide drinking water to an estimated 1.8 crore people, alleviating reliance on erratic groundwater and tanker supplies during dry seasons.[75][76]Government officials assert that the diversion captures only surplus monsoon runoff—estimated at less than 10% of the basin's annual yield—that would otherwise flow unused to the Arabian Sea, ensuring no depletion of base flows critical for downstream ecosystems like the Netravati River. The first phase, inaugurated by Chief MinisterSiddaramaiah on September 6, 2024, at a total revised cost exceeding ₹23,000 crore, has already enabled pre-commissioning tests on weirs and pipelines, with initial supplies reaching parts of Chikkaballapur and Kolar districts. Proponents highlight ancillary benefits, including reduced migration from rural areas due to improved water security and potential for localized economic upliftment through stabilized agriculture in rain-fed zones, though the project is explicitly designated for domestic use only, excluding irrigation or hydropower allocation.[77][47][78]In response to environmental and socioeconomic protests, primarily from coastal Karnataka stakeholders fearing ecological harm to the Netravati basin, the government has cited regulatory approvals from the National Green Tribunal (NGT) in 2018 and subsequent environmental clearances as validation of the project's viability and minimal impact. Officials have dismissed claims of river drying as exaggerated, pointing to hydrological studies indicating adequate residual flows post-diversion, and have committed to compensatory afforestation covering over 1,000 hectares to offset forest land use. Despite central government notifications in April 2025 flagging potential violations of forest conservation laws, state authorities proceeded with inauguration, arguing that the project's drinking water priority overrides minor procedural lapses and that ongoing monitoring would address wildlife corridor disruptions. The administration has also allocated 219.44 MW of power for operations, with an annual electricity cost of around ₹150 crore, framing these investments as necessary for long-term human welfare in arid interiors over unsubstantiated opposition narratives.[74][79][80]