KEY TAKEAWAYS
- OverAbstraction Threatens Groundwater Sustainability: Studies confirm that over-extraction of groundwater for agriculture and domestic use has led to declining water tables nationwide, with northern arid regions, Niger delta region and urban centers like Lagos particularly vulnerable.5)
- Poor Drilling Practices Worsen the Crisis: Many borehole projects skip geophysical surveys, resulting in low-yield wells, aquifer damage, and issues like pollution, saltwater intrusion, and land subsidence, which increase costs and threaten water security.
- Geophysical Surveys Are Essential: These surveys provide critical data to locate viable aquifers and guide sustainable drilling, but cost-cutting and weak regulations lead to their underuse, causing inefficient and harmful groundwater extraction.
- Multi-Pronged Solutions Are Needed: Strengthening regulations, leveraging technologies like remote sensing, promoting public awareness, encouraging private sector water conservation, and exploring alternative sources like rainwater harvesting are crucial to manage groundwater effectively.
- Collaboration Is Key: Partnerships between government, businesses, and communities are vital to implement science-based policies, enforce sustainable practices, and secure Nigeria’s groundwater for future generations while mitigating environmental and economic risks.
INTRODUCTION
Did you know that Nigeria’s groundwater resources in urban settings are under severe pressure, with some areas experiencing alarming drops in the water table? Over-abstraction of groundwater undermines the sustainability of this vital water source that supplies most of our drinking water. While drilling for groundwater continues to rise across the country to meet water demands, the lack of adherence to recommended geophysical survey practices and drilling guidelines exacerbates the problem. Understanding the causes, challenges, and solutions is critical to preserving Nigeria’s groundwater for current and future generations.
NIGERIA’S GROWING DEPENDENCE ON GROUNDWATER
Groundwater accounts for nearly 60% of Nigeria’s potable water supply(3), particularly in rural and semi-urban communities with limited surface infrastructure. These areas are heavily reliant on groundwater due to the limited and inconsistent availability of surface water sources and the lack of developed water supply systems. For example, the interplay of hydro-geological characteristics in the northern part of the Kano region makes surface water virtually inadequate, and as such, groundwater appears to be the only reliable source of fresh water for domestic and agricultural use. (17) Groundwater offers a reliable and readily accessible source of clean water, especially in regions where centralized water systems are either absent or underdeveloped. However, rapid population growth, expanding agricultural irrigation, and increasing industrial activities have intensified groundwater demand. Over the past two decades, Nigeria has witnessed a substantial increase in borehole drilling, primarily driven by the urgent need to access clean water. However, many of these boreholes have been established without adequate scientific assessment or regulatory oversight, leading to unsustainable groundwater extraction and escalating concerns about water quality. (5).
Geophysical Surveys are scientific assessment techniques that use subsurface data to locate water-bearing formations for effective and sustainable groundwater development. Unfortunately, many drilling projects proceed without such surveys or disregard their recommendations, resulting in low-yield wells, aquifer damage, and premature depletion.
Regions such as the north-central and southwestern parts of Nigeria have reported critical groundwater shortages, with falling water tables and increased well failures becoming common. Without proper management, these trends threaten not only water security but also the socioeconomic stability of affected communities.
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- Lowering of water tables: In Ado-Ekiti, excessive groundwater extraction due to population growth has led to a steady decline in water tables(15). This mirrors trends in other urban centers, where boreholes dry up faster, forcing households and businesses to drill deeper at higher costs⁷. In Northern Nigeria, transboundary aquifers such as the Chad Basin are under intense pressure, with widespread depletion threatening long-term water security(16). Without intervention, water scarcity will worsen, particularly in semi-arid regions.
- Water Crises: While Nigeria’s groundwater crisis is often framed in environmental or technical terms, its deepest impacts are felt in livelihoods, public health, and social stability. Over-abstraction and poor drilling practices do not just lower water tables—they disrupt economies, spread disease, and fuel tensions in already vulnerable regions.
- Pollution and sedimentation of groundwater supplies: When water levels drop, the concentration of pollutants in the aquifer can increase, as there is less water to dilute contaminants. Studies in Onitsha North LGA reveal high acidity levels in boreholes, demonstrating how groundwater depletion concentrates pollutants(12). In the Niger Delta, industrial waste and agricultural runoff have seeped into shallow aquifers(11), aggravating Nigeria’s water crisis. As water tables drop, sediment enters boreholes, reducing pump lifespan and raising maintenance costs. This decline in water quality forces many communities to rely on expensive purification methods or risk consuming contaminated water.
- Saltwater Intrusion: Coastal aquifers in Lagos have suffered from saltwater intrusion, a direct consequence of over-abstraction. Boreholes in affected areas are turning brackish, making them unsuitable for domestic use. This has led many residents to seek alternative sources, increasing reliance on expensive bottled water or tanker services. Saltwater intrusion is particularly severe in areas where boreholes are drilled indiscriminately without proper geophysical surveys.
- Land Subsidence: In urban areas, sinking ground caused by over-pumping can damage infrastructure, including buildings, roads, and pipelines. This is a growing concern in Lagos, where excessive groundwater pumping causes sediment compaction and lowers pore pressure in aquifers(13). This leads to the gradual sinking of the land, especially in coastal and reclaimed alluvial areas. Subsidence increases flooding risks and damages infrastructure.
The severe consequences of over-abstraction highlight the urgent need for accurate assessment and sustainable management of groundwater resources. This is where geophysical surveys play a critical role, providing the scientific data necessary to locate viable aquifers and guide responsible drilling practices.
WHY GEOPHYSICAL SURVEYS ARE CRUCIAL
Setting out on a journey without a clear map increases the risk of costly mistakes and dead ends. This is exactly what drilling for groundwater without a geophysical survey. Geophysical surveys accurately identify aquifer boundaries, thickness, and quality, including contamination or salinity zones(14). They guide optimal well placement to maximize yield while minimizing environmental harm. Despite the critical nature of these surveys, many contractors prioritize cost and speed, leading to substandard borehole construction and inefficient water extraction.
Proper drilling practices require adherence to technical guidelines informed by geophysical data and hydrogeological expertise. These guidelines include drilling to appropriate depths for sustainable aquifers, controlling pump capacity to avoid over-extraction, protecting recharge zones from contamination, and using proper casing and sealing to prevent pollutants from entering aquifers. However, in practice, many drilling contractors bypass geophysical survey results or omit conducting the surveys. Wells are often drilled too shallow or in inappropriate locations, resulting in dry or low-yield wells. The use of oversized pumps accelerates aquifer depletion. Compounding these problems, regulatory oversight and enforcement are often weak or inconsistent. This disregard for scientific recommendations inflates operational costs, wastes resources, and hastens groundwater depletion.
RECOMMENDATIONS
To address the challenges of groundwater over-abstraction in Nigeria, a focused and multi-pronged approach is essential. The following recommendations will help guide Nigeria towards sustainable groundwater management:
- Strengthen Regulations and Enforcement: Nigeria must enforce strict regulations that mandate geophysical surveys before drilling to ensure groundwater extraction remains within sustainable limits. Key agencies, including the Nigeria Hydrological Services Agency (NIHSA), the Nigeria Integrated Water Resources Management Commission (NIWRMC), Rural Water Supply and Sanitation Agencies (RUWATSSAN), and the National Water Resources Institute (NWRI), are essential in monitoring, regulating, and managing the nation’s groundwater resources to prevent over-extraction and ensure long-term water security.
- Leverage Technology for Better Monitoring: Adopting advanced technologies like remote sensing, real-time monitoring, and advanced geophysical surveys can improve the precision with which groundwater resources are located and monitored(7).
- Promote Public Awareness and Community Involvement: Educating local communities on the importance of sustainable groundwater use is key. Public awareness campaigns and community-driven initiatives can help prevent over-extraction and encourage responsible water management.
- Encourage Private Sector Responsibility: Industries should be encouraged to invest in water conservation practices, including water recycling and alternative water sources. Public-private partnerships can play a significant role in reducing pressure on aquifers while supporting economic growth.
- Explore Alternative Water Sources: To reduce dependence on groundwater, Nigeria should invest in alternative water sources such as rainwater harvesting, desalination in coastal areas, and wastewater treatment for reuse, which can ease the strain on aquifers.
- Foster Collaboration for Integrated Water Management: Collaboration between government agencies, businesses, and communities is crucial for effective water resource management. This partnership can help develop sustainable solutions and ensure comprehensive management of groundwater.
CONCLUSION
Nigeria’s groundwater is critically depleted due to over-extraction and poor drilling practices, leading to water table declines, pollution, saltwater intrusion, and land subsidence. To prevent further damage, strict regulations mandating geophysical surveys and advanced monitoring technologies are essential. Public awareness, private sector involvement in conservation, and exploring alternative water sources like rainwater harvesting must be prioritized. The government, businesses, and communities must collaborate on sustainable solutions to secure Nigeria’s groundwater resources and ensure a reliable water supply for future generations because, without urgent action, Nigeria’s water crisis could escalate into a full-blown disaster.
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