The Srisailam Left Bank Canal (SLBC) Tunnel Project, officially known as the Alimineti Madhava Reddy Srisailam Left Bank Canal Project (AMRP-SLBC), is a major irrigation initiative in Telangana. Designed to tackle water scarcity, the project aims to divert Krishna River water to Nalgonda and nearby drought prone districts, benefiting over four lakh acres of farmland and providing drinking water to fluoride affected villages.
First conceptualised in 1983, the project has undergone multiple revisions and delays, evolving into one of the most ambitious irrigation projects in South India.
Background: The Nalgonda district and surrounding areas have long faced severe droughts and groundwater contamination. High levels of fluoride in drinking water have caused major health concerns, making sustainable water management a necessity.
To address this, the government planned a water diversion system using the Krishna River, particularly the Srisailam and Nagarjuna Sagar reservoirs. The project was designed to:
Irrigate 4.09 lakh acres of farmland.
Provide drinking water to 516 fluoride affected villages.
Ensure water supply to drought-prone regions.
Here are the key milestones related to the project:
1983: SLBC project approved for irrigation.
1995: Lift irrigation scheme introduced as an interim measure.
2004: Tunnel system approved as a permanent solution.
2005: Government sanctioned ₹2,813 crore for tunnel construction.
2015: Revised project cost increased to ₹3,152 crore.
2020s: Tunnel and reservoir work continues.
Project design and functioning: The SLBC project has two primary components: a tunnel system and a lift irrigation scheme.
Aerial view of Krishna River and SLBC tunnel inlet side
Tunnel system (Gravity-based water transfer)
The tunnel system is the backbone of the project, allowing water to flow from the Srisailam Reservoir to Nalgonda through an underground passage.
Tunnel Boring Machine (Representative image)
Tunnel 1: 43.9 km long, excavated using a Tunnel Boring Machine (TBM).
Tunnel 2: 7.1 km long, built using the Drilling and Blasting method.
Dindi Balancing Reservoir: Regulates water flow with a 7.54 TMC capacity.
Water from the tunnels is released into canals and balancing reservoirs for irrigation and drinking purposes.
Lift irrigation scheme (Pumping-based water transfer)
Since tunnels take time to construct, a lift irrigation scheme was introduced in 1995 to provide immediate benefits. This system lifts water from Nagarjuna Sagar Reservoir to higher elevations for distribution.
High-Level Canal Lift: Lifts water 100m to irrigate 2.29 lakh acres.
Low-Level Canal Lift: Lifts water to irrigate 50,000 acres.
Here are technical aspects related to the tunnels and water flow:
Pumping stations: Two major stations (High and Low Level)
Total power requirement: 72 MW
Main canals length: 196 km
Challenges and delays: Despite being approved in 1983, the SLBC project remains unfinished due to multiple challenges.
Construction challenges
Tunnel excavation has been slow due to complex geology.
Foreign technology dependence delayed progress.
Financial and administrative delays
The original budget of ₹2,813 crore was later revised to ₹3,152 crore.
Slow approvals caused construction stoppages.
Land acquisition issues
32,000 acres of land were needed, but some areas remain disputed.
Legal cases and protests have slowed land clearance.
Environmental and social concerns
The tunnels pass through wildlife zones, raising ecological concerns.
Villages were displaced, leading to rehabilitation challenges.
Expected impact: When completed, the SLBC project will:
Provide a permanent irrigation solution to drought hit areas.
Ensure safe drinking water in fluoride affected villages.
Boost Telangana’s agricultural economy.
The project is expected to revolutionise water distribution in Telangana and provide long-term relief to farmers and rural communities.
The government continues to prioritise the completion of tunnels, reservoirs, and canal systems. The SLBC project is a cornerstone of Telangana’s water management strategy and, when fully functional, will be a lifeline for the state’s agricultural sector.
The SLBC Tunnel Project is vital for Telangana’s water security and agriculture. However the tunnel collapse on Saturday is a harsh reminder of the risks in such massive projects. Lives were put in danger. Work has been delayed. This should not happen. Strict safety measures must be in place at every stage. Risk assessments must be thorough. Only high quality materials must be used. Those responsible for negligence must be held accountable. Companies cutting corners must face action. The government must ensure worker safety, structural integrity, and strict oversight. The SLBC project is a lifeline. It must be built with care, caution, and commitment, not at the cost of lives.
Irrigation Profile of Nalgonda District and SLBC’s Role
The Nalgonda district, where the SLBC Tunnel Project is being developed, plays a crucial role in Telangana’s irrigation network. The district lies in southern Telangana, bordered by Medak, Warangal, Guntur, Mahabubnagar, Khammam, Krishna, and Ranga Reddy districts. It has a total geographical area of 35.19 lakh acres, of which 69.5% is cultivable.
Existing irrigation infrastructure: Nalgonda’s irrigation system heavily relies on major, medium, and minor projects, including:
Nagarjunasagar Project (Largest, with 3.78 lakh acres of irrigated land)
Musi Project (30,183 acres created, 21,000 acres utilised)
SLBC’s importance among ongoing projects: The SLBC Tunnel Project is among the largest ongoing irrigation projects in Telangana, aiming to irrigate 2.7 lakh acres. It is part of a broader effort to expand irrigation, alongside:
These projects collectively aim to irrigate over 7 lakh acres across the region.
Why SLBC stands out: Unlike traditional canal-based irrigation, SLBC uses a tunnel system and lift irrigation to ensure a steady water supply to drought prone areas. Given that only 20.35% of Nalgonda’s total area is currently irrigated, the completion of SLBC will significantly boost agricultural productivity and reduce dependency on groundwater sources.
This data highlights Nalgonda’s irrigation landscape and reinforces the critical role of SLBC in addressing water shortages and agricultural expansion in the region.
(Based on official documents from the Irrigation & CAD Department, Government of Telangana)
