Concrete Lining of KB Feeder Raises Ecological Concerns in Lower Sindh
Experts warn KB Feeder concrete lining may damage groundwater, biodiversity, and livelihoods in lower Sindh despite Rs50.9bn canal upgrade.
THATTA: The recent partial structural failure of the Kalri Baghar Feeder (KB Feeder Upper) has intensified environmental concerns across lower Sindh, with water and climate experts warning that the Rs50.9 billion canal “improvement” project could have long-term ecological consequences for the Indus Basin and its dependent communities.
The canal, which channels water from the Indus River system toward Karachi, was recently lined with rigid concrete (PCC) to minimise seepage losses. However, critics argue that the intervention may disrupt natural hydrological processes that have historically sustained aquifers, ecosystems, and rural livelihoods in Thatta, Jamshoro, and adjoining districts.
What Is the KB Feeder Project?
The KB Feeder is a critical water artery designed to transport freshwater from the Indus system to urban centres, particularly Karachi. The lining project aimed to enhance efficiency by reducing seepage and conserving water — with the Irrigation Department estimating savings of up to 550 cusecs.
But while the engineering rationale focused on water efficiency and urban supply security, environmental experts argue that the project overlooked the ecological role of seepage in lower Sindh’s fragile landscape.
The February 3 collapse of several concrete sections has further raised questions about structural durability and environmental planning.
Groundwater Recharge at Risk
Obhayo Khushk, a water expert and former Superintendent Engineer of the Irrigation Department, warned that the canal’s original earthen banks played a vital ecological function.
Historically, unlined canals in Sindh acted as groundwater recharge channels, allowing freshwater to percolate into surrounding aquifers. In an arid region like lower Sindh, this seepage supports agriculture, drinking water supplies, and natural vegetation.
By replacing porous soil with concrete, the project has effectively blocked this recharge mechanism.
“Concrete lining acts as an aquifer barrier,” Mr Khushk observed, adding that extensive research across the Indus Basin demonstrates the importance of seepage in sustaining freshwater reserves.
Given that nearly 78 percent of Sindh’s groundwater is already brackish, restricting freshwater infiltration could worsen saline intrusion, particularly in downstream and deltaic regions.
Salinity and the Indus Delta Threat
Lower Sindh, including parts of Thatta and the Indus Delta, is already facing severe salinity challenges due to reduced freshwater flows and seawater intrusion.
Experts caution that reduced seepage from the KB Feeder may further weaken freshwater pressure in underground aquifers. Without sufficient recharge, saline water could spread deeper inland, rendering agricultural land unproductive.
In deltaic ecosystems that depend on a delicate balance between freshwater and seawater, even small hydrological shifts can have large ecological consequences.
If salinity intensifies, it could affect crop yields, drinking water quality, and biodiversity in coastal districts.
Heat-Sink Effect and Evaporation Concerns
Beyond groundwater implications, climate specialists have raised concerns about the potential “heat-sink effect” of exposed concrete surfaces.
With summer temperatures in Sindh frequently exceeding 48°C, concrete absorbs and radiates heat more intensely than natural soil banks. This could increase water temperatures within the canal, accelerating evaporation and placing thermal stress on aquatic organisms.
Anees Hillayo, president of the Keenjhar Conservation Network, noted that natural earthen banks once supported vegetation that moderated microclimates and reduced direct solar exposure.
“The presumed water savings may be offset by increased evaporation and ecological stress,” he said.
In a warming climate, infrastructure design must account not only for hydraulic efficiency but also for thermal and ecological resilience.
Biodiversity and Riparian Habitat Loss
The canal redesign has also resulted in the widespread removal of riparian vegetation. These plant systems previously stabilised soil, provided shade, and supported diverse species.
Shafi Murghar, head of the Delta Development Organisation, highlighted the loss of slow-moving water pockets and vegetative cover that sustained amphibians, reptiles, and the endangered smooth-coated otter.
Riparian corridors function as ecological bridges, supporting bird nesting, aquatic breeding, and wildlife movement. Their removal reduces biodiversity and weakens ecosystem resilience.
The steep concrete walls now limit access for wildlife and livestock, eliminating natural drinking points and escape pathways.
Structural Collapse and Safety Risks
The February 3 structural failure added urgency to the debate.
Fractured concrete slabs created concentrated leakage points, causing localised waterlogging and soil erosion. Ironically, while the lining was intended to prevent seepage, structural damage has produced uncontrolled leakages that may undermine adjacent land.
Environmental observers warn that the steep, smooth embankments also pose safety risks. Livestock and wildlife attempting to access water may struggle to climb out, effectively turning sections of the canal into a potential “death trap.”
Such unintended consequences raise questions about whether ecological impact assessments were adequately integrated into project design.
Socio-Economic Impact on Canal Communities
The KB Feeder supports hundreds of villages along its course. Communities rely on the canal for livestock watering, domestic use, fishing, and small-scale agriculture.
Yasmeen Shah, vice chairperson of the Pakistan Fisherfolk Forum and head of the Noori Development Organisation, stated that more than 1,000 livestock animals have reportedly lost safe access to water due to the steep embankments.
Affected communities claim they were neither adequately consulted nor provided with alternative infrastructure such as cattle ramps or designated access points.
For rural households already facing economic vulnerability, such disruptions can have cascading livelihood impacts.
Policy Criticism: River as Pipeline?
Critics argue that the KB Feeder project reflects a broader policy trend prioritising urban water transfer to Karachi over ecological sustainability in lower Sindh.
Dr Muhammad Ali Manjhi, a noted environmentalist, suggested that policymakers may be treating the Indus as a mere conduit for city supply, rather than a living river system supporting diverse ecosystems and cultures.
The Indus River system sustains agriculture, fisheries, wetlands, and delta communities. Altering its hydrology without comprehensive environmental analysis may generate long-term costs that outweigh short-term gains.
Balancing urban water security with ecological integrity remains one of Sindh’s most complex governance challenges.
Calls for Environmental Impact Assessment
As authorities prepare repair work under the defect liability clause, environmental experts are demanding a comprehensive Environmental Impact Assessment (EIA).
Water and climate specialists, including Obhayo Khushk and Anees Hillayo, recommend exploring nature-based solutions such as:
- Bio-engineered embankments
- Controlled seepage zones for aquifer recharge
- Wildlife escape ramps
- Designated cattle ghats
- Vegetative shading systems
Nature-based infrastructure can enhance water efficiency while preserving ecological functions.
Environmental groups argue that integrating ecological hydrology into engineering design is not optional but essential in climate-vulnerable regions like Sindh.
The Road Ahead
The KB Feeder concrete lining project was conceived as a water-saving intervention. Yet its unintended ecological, hydrological, and socio-economic consequences highlight the need for integrated planning.
Lower Sindh already faces climate stress, salinity intrusion, biodiversity decline, and water scarcity. Infrastructure decisions must account for these layered vulnerabilities.
Without a balanced approach that considers groundwater recharge, ecosystem services, community livelihoods, and climate resilience, the KB Feeder project risks becoming a cautionary tale.
Experts warn that the consequences of overlooking ecological hydrology could extend far beyond the canal’s concrete walls — affecting the Indus Basin’s long-term sustainability.
