Krishna River

The Krishna River is the second-largest eastward-flowing peninsular river in India, playing a vital role in the agro-economy of Southern India. It originates at an elevation of approximately 1,337 meters above mean sea level from a glacial spring at Mahabaleshwar, located on the eastern slopes of the Sahyadri Range (Western Ghats) in the Satara district of Maharashtra. The source is mythologically and structurally anchored at the ancient Panchganga Temple, where five local streams converge.

Fluvial Trajectory and Inter-State Course

The Krishna River flows over a total structural length of 1,400 kilometers before discharging into the Bay of Bengal. It flows east-southeast across the basaltic terrain of the Deccan Plateau, traversing four major states: Maharashtra, Karnataka, Telangana, and Andhra Pradesh. The river cuts across the semi-arid rain-shadow districts of Rayalaseema and Northern Karnataka, carves deep gorges through the Eastern Ghats at Srisailam, and enters the flat coastal plains of coastal Andhra Pradesh.

Terminal Delta and Estuarine Discharge

The river reaches its apex point of bifurcation near Vijayawada. It discharges into the Bay of Bengal through three primary distributary arms at Hamsaladeevi in the Krishna district of Andhra Pradesh. The Krishna forms an arcuate delta that actively advances into the sea. This deltaic region merges with the southern fringe of the Godavari delta, sandwiching the freshwater Kolleru Lake between the two river systems.

Hydrological and Basin Parameters

Catchment Allocation Matrix

The Krishna basin encompasses a total drainage area of 258,948 square kilometers, which accounts for nearly 7.8% of the total geographical area of India. The basin is geographically bounded by the Balaghat Range on the north, the Eastern Ghats on the south and east, and the Western Ghats on the west.

Physiographic and Climatic Zones

The basin is structurally divided into three distinct zones: the high-rainfall Western Ghats crest line, the dry plateau region of the western and central Deccan (Kurnool-Cuddapah formations), and the fertile deltaic plains. The middle basin receives less than 600 mm of annual rainfall, making it highly vulnerable to chronic meteorological droughts.

Tributaries of the Krishna River

The drainage architecture of the Krishna River is highly dense and asymmetric, receiving major voluminous systems from both its banks. The left-bank tributaries drain the central Deccan plateau, while the right-bank tributaries carry high volumes of water gathered from the crest line of the Western Ghats.

Right-Bank Tributaries

• Tungabhadra River: The largest and most critical tributary of the Krishna, contributing nearly 40% of its total water volume. It is formed by the confluence of the Tunga and Bhadra rivers at Kudli in Shivamogga, Karnataka. It runs northeastward along the Deccan plains, passes the historic ruins of Hampi, and joins the Krishna near Gondimalla in Telangana.
• Koyna River: Rises near Mahabaleshwar and runs southward before taking a sharp eastward turn to join the Krishna at Karad (Preeti Sangam). It is famous for the Koyna Dam, which controls the upper hydrological regime of Maharashtra.
• Ghataprabha River: Originates in the Western Ghats of Sindhudurg, flows eastward through Belagavi district, and forms the Gokak Falls before its confluence with the Krishna at Almatti.
• Malaprabha River: Rises from the Sahyadris in Belagavi, flows through Bagalkot, and meets the Krishna at Kudalasangama. Its valley houses the UNESCO World Heritage sites of Pattadakal and Aihole.
• Panchganga River: Formed by five streams (Kasari, Kumbhi, Tulsi, Bhogavati, and Sarasvati) near Kolhapur, delivering high-velocity monsoonal runoff to the upper Krishna.
• Dudhganga and Venna Rivers: Short, high-gradient mountain streams that feed the upper catchment zone within Maharashtra.

Left-Bank Tributaries

• Bhima River: The longest tributary of the Krishna, flowing over a length of 861 kilometers. It rises from the Bhimashankar hills in Pune, Maharashtra, flows through Solapur, and runs along the Karnataka border before merging with the Krishna near Raichur.
• Musi River: A major rain-fed stream that originates in the Ananthagiri Hills of Vikarabad and flows through Hyderabad city. It joins the Krishna near Wazirabad in Nalgonda district.
• Munneru River: Drains the eastern parts of Telangana and Andhra Pradesh, joining the Krishna downstream of the Pulichintla project.
• Paleru River: A seasonal left-bank stream that flows through the Khammam district to feed the middle course of the river.
• Dindi River: Rises in the Mahbubnagar hills, draining the limestone-rich formations before its confluence near the Srisailam reservoir.

Multipurpose River Valley Projects and Infrastructure

The Krishna basin contains a cascading network of mega-dams and lift irrigation schemes designed to manage water resource allocation among the four riparian states.

Nagarjuna Sagar Dam

Located on the border of Guntur district (Andhra Pradesh) and Nalgonda district (Telangana), this is the world’s largest masonry dam. It creates a massive reservoir that supplies water to the Left Bank Canal (Lal Bahadur Shastri Canal) and the Right Bank Canal (Jawahar Canal), stabilizing agriculture across coastal Andhra Pradesh.

Srisailam Project

Constructed across a deep gorge in the Nallamala Hills on the border of Kurnool (Andhra Pradesh) and Mahbubnagar (Telangana). It serves as a major strategic water storage asset, feeding underground power houses with a combined capacity of 1,670 MW and supplying water to the Pothireddypadu head regulator.

Almatti Dam (Upper Krishna Project Stage-I)

Located in the Bijapur district of Karnataka, this project regulates water releases for northern Karnataka. The reservoir behind the dam is named the Lal Bahadur Shastri Reservoir and acts as the primary feed node for downstream irrigation structures.

Narayanpur Dam

Situated downstream of the Almatti Dam in Yadgir district, Karnataka, it acts as a balancing reservoir to divert water into the Narayanpur Left Bank Canal network.

Prakasam Barrage

Located at Vijayawada, this terminal structure spans over 1.2 kilometers across the Krishna River. Built originally by Sir Arthur Cotton and later modernized, it diverts the final regulated flows of the river into the Krishna delta canal system, transforming Krishna and Guntur into major rice bowls.

Geopolitical Context and Inter-State Water Sharing

The Krishna Water Disputes Tribunal (KWDT)

The distribution of the Krishna waters has been a subject of long-standing legal conflict. The first tribunal (KWDT-I) was set up in 1969 under the Inter-State River Water Disputes Act, 1956, headed by Justice R.S. Bachawat, which allocated water based on 75% dependability. The second tribunal (KWDT-II), headed by Justice Brijesh Kumar in 2004, modified allocations to 65% dependability and allowed Maharashtra to raise the height of the Koyna dam and Karnataka to raise the Almatti dam.

Post-Bifurcation Hydrological Disputes

Following the bifurcation of Andhra Pradesh in 2014, disputes emerged between Telangana and Andhra Pradesh regarding the sharing of the 811 TMC allocation. Telangana demands a reassessment under Section 89 of the Andhra Pradesh Reorganisation Act, claiming higher water rights for its drought-prone lift irrigation schemes like Palamuru-Ranga Reddy.

River Interlinking: The Polavaram Link

The Pattiseema Lift Irrigation Scheme links the Godavari and Krishna basins. It diverts surplus water from the Godavari River to the Krishna River upstream of the Prakasam Barrage via the Polavaram Right Main Canal, helping mitigate water deficits in the Krishna delta.

Environmental and Ecological Profile

The Krishna Wildlife Sanctuary

Located at the tip of the deltaic estuary in Andhra Pradesh, this sanctuary protects one of the last remaining pristine mangrove forests in South India. It acts as a major ecological barrier against cyclones and marine transgressions.

Flagship Fauna and Wetlands

• Smooth-Coated Otter (Lutrogale perspicillata): Thrives in the mangrove channels of the delta and faces threat from coastal aquaculture expansions.
• Fishing Cat (Prionailurus viverrinus): A vulnerable wetland felid that relies on the dense mangrove ecosystems of the Krishna estuary for its survival.
• Estuarine Crocodile: Found in the brackish water zones where the river channels merge with the Bay of Bengal.

High-Yield Trivia for Prelims Focus

The Dharwar Craton and Diamond Matrix

The middle and lower courses of the Krishna basin cut through the ancient Cuddapah Basin and the Dharwar Craton. The gravel beds of the Krishna River, particularly around Kollur in Guntur district, were historically the exclusive global source of large diamonds. The famous Koh-i-Noor and Hope diamonds were mined from the alluvial placers of the Krishna River basin.

The Krad-Preeti Sangam Tectonic Node

The confluence of the Krishna and Koyna rivers at Karad exhibits a unique geomorphic layout. The Koyna River hits the Krishna from the south in a reverse-direction alignment, indicating a drainage reversal triggered by the historical tectonic tilt of the Western Ghats block. This region lies close to the seismically active Koyna fault zone, which experienced a major reservoir-triggered earthquake in 1967.

The Srisailam Tiger Reserve Boundary

The Srisailam reservoir and gorge system runs directly through the core zone of the Nagarjunasagar-Srisailam Tiger Reserve, which is the largest tiger reserve by core area in India. The river serves as a natural administrative barrier between the tiger landscapes of Telangana and Andhra Pradesh.

Geomorphic Antecedent Gorges

As the Krishna cuts through the Nallamala hill range, it forms steep, deep rock walls. This morphology proves the antecedent nature of the river, showing it maintained its longitudinal course by vertical incision while the Eastern Ghats blocks underwent slow epeirogenic uplift.