Concept Page
Krishna River Basin
The Krishna River Basin is a major drainage system in southern India, covering parts of Maharashtra, Karnataka, Telangana, and Andhra Pradesh. It supports agriculture, hydro‑electric power, and biodiversity, making it a key economic and ecological lifeline. The basin’s largest reservoir, the Srisailam Dam, stores over 10 billion cubic metres of water.
Krishna River Basin — the catchment of the Krishna, India’s second‑longest south‑west flowing river, stretches over ≈ 258,900 km² across Maharashtra, Karnataka, Telangana and Andhra Pradesh. Originating at ≈ 1,300 m in the Western Ghats near Mahabaleshwar, the river runs ≈ 1,400 km to the Bay of Bengal, delivering water to ≈ 12 million ha of irrigated land and supporting a hydro‑electric capacity of ≈ 3 GW. Its sheer geographic reach, combined with a dense network of dams and inter‑state treaties, makes the basin a pivotal arena for India’s water‑security, energy, and biodiversity agendas.
Historical Background
The Krishna basin entered formal national policy with the 1956 Inter‑State River Water Disputes Act, which empowered the central government to adjudicate disputes among the four riparian states. The first Krishna Water Disputes Tribunal (KWDT‑I) delivered its award on 20 December 1969, allocating ≈ 1,200 tmcft (34 billion m³) among the states and establishing the Krishna River Management Board (KRMB) to oversee implementation. A second tribunal (KWDT‑II) in 1976 refined allocations, introducing the concept of “dependable yield” based on a 75‑year hydrological record, a benchmark still used in basin‑wide planning.
Hydrological Characteristics
The basin’s mean annual runoff averages ≈ 1,200 km³, with monsoonal peaks in July–September delivering ≈ 70 % of total flow. The river’s tributary network—comprising the Bhima, Tungabhadra, Koyna, and Musi—contributes ≈ 45 % of the basin’s discharge, while the downstream delta spans ≈ 8,000 km² and supports the ecologically sensitive Pulicat Lake, a Ramsar‑listed wetland. Seasonal variability is pronounced: during the 2019–2020 drought, reservoir levels fell to ≈ 30 % of live capacity, whereas the 2022 Belagavi floods saw peak inflows of ≈ 4,500 m³ s⁻¹, breaching several spillways.
Institutional Framework and Water Allocation
Beyond the KRMB, the Krishna River Basin Management Authority (KRBMA), notified in 2005 under the Water (Prevention and Control of Pollution) Act, coordinates pollution control and water‑quality monitoring across the basin’s 1,200 km of streams. The 2010 National Water Policy reinforced “integrated river‑basin management,” prompting the creation of the Krishna Basin Development Authority (KBDA) in 2014 to streamline irrigation projects. Allocation formulas derived from KWDT awards assign ≈ 41 % of dependable yield to Maharashtra, ≈ 30 % to Karnataka, ≈ 15 % to Telangana, and ≈ 14 % to Andhra Pradesh, with a 10 % reserve for ecological flow mandated by the 2020 National River Basin Management Plan.
Major Infrastructure and Utilisation
Srisailam Dam, commissioned in 1981, holds ≈ 9.34 billion m³ (33.3 tmcft) and powers ≈ 770 MW of hydro‑electricity, while Nagarjuna Sagar (operational 1967) stores ≈ 11.56 tmcft and contributes ≈ 816 MW. Downstream, Almatti (1999) and Koyna (1973) reservoirs add ≈ 7.5 tmcft (212 million m³) and ≈ 2.8 tmcft (79 million m³) respectively, together supporting ≈ 12 million ha of rice, sugarcane, and cotton cultivation. The basin’s irrigation network comprises ≈ 13,000 km of canals, delivering water to ≈ 4.5 million ha of command area, while the Krishna‑Godavari interlink project, approved in 2015, envisions transferring ≈ 1.5 tmcft to alleviate drought‑prone districts.
Current Challenges and Future Outlook
Rapid urbanisation in Hyderabad and Vijayawada has heightened demand, pushing per‑capita water use from ≈ 120 L day⁻¹ (1990) to ≈ 210 L day⁻¹ (2022). Climate models project a ≈ 15 % reduction in monsoon runoff by 2050, intensifying competition among states and threatening the ecological flow needed for the endangered Ganges river dolphin (Platanista gangetica). Sedimentation has reduced Srisailam’s live storage by ≈ 12 % since 1990, prompting the 2023 “Krishna Basin Revitalisation Initiative” to invest ₹ 12,000 crore in desiltation and smart‑metering. Integrated water‑resource management, bolstered by real‑time telemetry and basin‑wide stakeholder forums, is now central to policy discourse, aiming to balance agricultural productivity, energy generation, and the preservation of the basin’s rich biodiversity.