Journal of Environmental and Sustainable Development Studies Original Article |
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Harnessing Solar Water Pumping Technologies for Sustainable Water Supply in Kenya: A Case Study of Kajiado Central Sub-County, Kenya. A Retrospective Baseline Study.
Okwiri Minado Saad¹ Ali Hassan Khamah² Michael Kairu Murimi³ Mapema N4
¹ ² ³ Umma University, Kajiado, Kenya
4Indepth Data Institute, Nairobi
Correspondence: Okwiri Minado Saad, Umma University, P.O. Box 713-01100, Kajiado Kenya. Email: sminado@umma.ac.ke
Abstract
Kajiado County suffers from acute water scarcity caused by climate-driven droughts and surface-water deficits that severely threaten agro-pastoral livelihoods, forcing a reliance on groundwater extraction across unserved zones of Kajiado Central Sub-County. Weak regulatory oversight has led to uncoordinated, dense borehole clustering that causes localized static water tables to drop rapidly, while private water pricing strains household economies and unregulated extraction bypasses public health monitoring for hazardous geogenic fluoride. This study implements a comparative ex-post facto retrospective research design spanning a ten-year operational horizon (2015–2024) to evaluate the long-term performance of resource-efficient Solar Water Pumping Technology (SWPT) as an alternative to conventional diesel and grid regimes. Temporally, the study covers a ten-year horizon from 2015 to 2024 and relies exclusively on historic secondary datasets available as of December 2024; no projected or preliminary 2025 data are included. Synthesizing Common-Pool Resource (CPR) and Socio-Technical Systems (STS) theories, the study relies on archival secondary data sourced from the Kajiado County Ministry of Water, the Water Resources Authority (WRA), and public health registries, evaluated via the Mann–Kendall trend test, linear regression, and thematic analysis. The empirical findings reveal that transitioning to solar water pumping lowers operational costs by 60%–75% compared to diesel ( (Briscoe et al., 2022)), yet the zero-marginal cost of solar power creates an economic incentive for unrestricted over-pumping that accelerates aquifer drawdown, while the clean energy transition exhibits a major health compliance gap by routinely distributing untreated water that exceeds the WHO 1.5 mg/L fluoride threshold ( (Author, 2017)). Technical upscaling must be legally bound to institutional governance; this study provides an empirical baseline for the Kajiado County Government to enforce spatial drilling limits, embed solarized frameworks into the County Integrated Development Plan (CIDP), and deploy mandatory solar-powered defluoridation units to ensure long-term climate resilience and public safety.
Keywords: Solarization; Common-Pool Resources; Sustainable Water Supply; Socio-Technical Systems; Environmental Pollution.
Chronic water shortages in the semi-arid Kajiado Central Sub-County endanger the livelihoods of pastoralists and health outcomes of those living in the sub-county. Solar Water Pumping (SWP) is considered to be a sustainable adaptation strategy; however, its sustainability over time depends on social governance and physical infrastructure configurations. The challenges of the energy–water–health nexus are severe and intersecting in the context of water abstraction in Kajiado Central Sub-County. Switching from diesel-powered to clean energy—solar-powered water pumping—can generate significant cost savings, but this efficiency improvement has unwittingly spurred uncontrolled groundwater extraction. As a result, the neighborhood has experienced clustering of boreholes in close proximity, posing a threat to the structural stability of the local aquifer system. This environmental problem is compounded by an important public health concern: data from public health registries in Kajiado County indicate that over 70% of local groundwater sources regularly contain concentrations of geogenic fluoride well above the regulatory limit of 1.5 mg/L ( (University of Southern Mississippi, 2015); (Author, 2017)), and local communities suffer high rates of both dental fluorosis and skeletal fluorosis.
The structural issues of the energy–water–health nexus prevailing in Sub-Saharan Africa persist despite fragmented and inconsistent electricity distribution and high fossil fuel price risks faced by rural and peri-urban water supply systems. In Kenya’s arid and semi-arid lands (ASALs) including Kajiado County, groundwater is tapped as an interdependent means of providing water for domestic, livestock, and commercial purposes. Traditionally, these groundwater systems have been powered by diesel-fueled generators, a large financial burden for marginalized communities due to high costs of operation and maintenance. Between 2015 and 2024, climate change prompted a strong shift toward green technology. Solar water pumping transformed farming and community water access. Backed by the National Treasury and programmes like FLLoCA, these systems provide low-cost, clean water free from grid failures and carbon emissions.
Traditionally, using diesel engines to pump from deep aquifers has posed huge challenges, with diesel fuel accounting for over 30–40% of farm and community operational costs, frequent mechanical breakdowns, difficult fuel supply logistics, and significant carbon emissions in sensitive areas. Fortunately, Kajiado County has very good solar conditions with high irradiance ranging from 5.5 to 6.5 Peak Sun Hours (PSH) per day, and strong daytime radiation exceeding 900 W/m² ( (Bwire, 2020)). The renewal of community and agricultural boreholes with solar water pumping technology (SWPT) offers a compelling solution. Through the utilization of the substantial solar energy resource in the sub-county, SWPT eliminates recurring fuel costs, stops the emission of pollutants, reduces operational maintenance, and ensures the climate-resilient water supply needed to support better food security and livelihoods in Kajiado Central ( (Argaw, 2004); (Rijsberman, 2006); (Cloutier & Rowley, 2020)).
However, if such technology is introduced without robust regulations, unintended consequences arise. Where pumping costs approach zero, communities may pump water without restriction. This has led to high densities of boreholes within the Kajiado Rift aquifer, posing a risk to the long-term sustainability of the aquifer. Furthermore, the volcanic rocks in this region contain abundant geogenic fluoride that naturally dissolves into groundwater ( (Author, 2017)). Consequently, cascading solar water infrastructure without embedded water treatment systems may become a vector for distributing high-fluoride water to vulnerable populations, effectively solving the energy problem while creating a serious public health crisis. The 2019 Kenya Population and Housing Census shows that Kajiado Central Sub-County has a population of 161,862 people spread across 37,000 households, giving a population density of approximately 38 persons per km². The Water Asset and Operation and Maintenance dashboard by Kajiado County Government covers shared water systems in the county, and the Arid Lands Information Network Renewable Energy Atlas identifies boreholes as keystones of the water infrastructure, particularly when combined with seasonal water rivers and earth dams in the region.
The Kajiado County Integrated Development Plan (2023–2027) identified water scarcity as a major challenge confronting the county, especially in its arid and semi-arid parts. A recent report by the National Drought Management (Kale & Kashid, 2024) indicates that from September to November 2022, Kajiado lost 38.8% of its livestock population and 400,000 households faced food insecurity. Herders’ losses were estimated at approximately KES 13 billion as a consequence of livestock deaths, child malnutrition, school dropouts, and unavailability of milk for nursing mothers and infants ( (Sturman & Quénol, 2023)). As defined by Local Governments for (Thompson & Norris, 2021), a solar water pump (SWP) is a type of electric water pump powered by photovoltaic (PV) panels that generate electricity to drive the pump. SWPs provide water to areas not connected to the electric grid and are appropriate for Kajiado County’s impoverished urban, peri-urban, and rural communities that lack electricity, have fewer environmental concerns, and benefit from lower operational and maintenance costs.
The core problem addressed by this study is the critical lack of longitudinal empirical evidence monitoring the operational durability, institutional governance, and socio-technical alignment of solarized water assets in Kenya’s arid and semi-arid lands. In Kajiado Central Sub-County, chronic water scarcity poses a continuous threat to pastoralist livelihoods, public health, and livestock survival ( (Martinez, 2025)). Relying on seasonal water pans or high-cost diesel boreholes has proven unsustainable, driving high rates of waterborne illness and diverting critical labour hours to water fetching. While solar water pumping technologies (SWPT) have been widely deployed by state and non-state actors as a clean alternative, their long-term viability is undermined by a complex web of institutional and technical failures. The Kajiado Water Asset Registry records indicate a borehole non-functionality rate of approximately 35–40% at any given time across the sub-county, compared to a regional benchmark of 25–30% for comparable ASAL counties in Kenya, underscoring the severity of operational failures ( (Elmard Ogweno et al., 2023)).
Synthesizing Common-Pool Resource (CPR) and Socio-Technical Systems (STS) theories reveals that these assets suffer from weak user ownership, inadequate local tariff collection, and a poor alignment between traditional pastoralist migration patterns and the mechanical limits of solar arrays. This mismatch often culminates in accelerated aquifer depletion and systemic pump abandonment. Because existing literature lacks a comprehensive, ex-post facto retrospective evaluation of these assets over a ten-year operational horizon (2015–2024), policymakers lack the data necessary to design sustainable interventions. This baseline study addresses this gap by establishing a diagnostic framework to transition decentralized water management from reactive crisis response to proactive, climate-resilient planning.
The significance of this baseline study spans practical, theoretical, and methodological dimensions, offering vital insights for stakeholders operating at the intersection of clean energy, public health, and climate adaptation in arid environments.
Practically, the study equips the Kajiado County Government with empirical data to shift the County Integrated Development Plan (CIDP) from reactive emergency water trucking toward data-informed, proactive solar asset management. By capitalizing on local solar exposure, the study outlines paths to insulate agro-pastoralists from volatile diesel markets, securing local food systems during droughts. Furthermore, it gives development donors sub-county level metrics to ensure future investments favor long-term lifecycle sustainability over quick installation goals, while warning public health regulators that clean energy expansion must be legally paired with mandatory fluoride testing.
Theoretically, the study advances Common-Pool Resource (CPR) literature by exploring a modern paradox: how zero-marginal-cost solar power can inadvertently accelerate a ‘Tragedy of the Commons’ in unmanaged aquifers. It simultaneously expands Socio-Technical Systems (STS) theory by evaluating how advanced green hardware embeds within traditional African pastoralist structures and environmental constraints. Methodologically, the study’s comparative ex-post retrospective design establishes a clear blueprint for infrastructure lifecycle assessments, demonstrating that analyzing the real-world operational durability of mature assets provides vastly superior developmental insights compared to examining only pristine, newly installed systems.
The rationale for this baseline study stems from the urgent need to decouple rural water security from carbon-intensive, high-cost energy regimes in Kenya’s arid lands. Solar Water Pumping Technology (SWPT) has emerged as a premier decentralized solution in areas where conventional grid infrastructure is absent, unreliable, or prohibitively expensive. This study evaluates the ten-year empirical trajectory of solarized boreholes in Kajiado Central to align localized resource management with global mandates, specifically UN Sustainable Development Goals 6, 7, 13, and 5.
Historically, the volatility of diesel fuel pricing has placed an unviable economic burden on low-income pastoralist communities, frequently causing operational shutdowns of community water assets. This research captures the longitudinal cost-reduction curves of solar transitions, illustrating how lowering operational expenditures can systematically stabilize consumer tariffs and reduce the regional carbon footprint.
Beyond macro-economic metrics, the study establishes an essential data baseline for regional regulators. The resulting empirical insights provide the Kajiado County Government and the Water Resources Authority (WRA) with the evidence required to enact protective institutional reforms. These insights are vital for establishing data-driven spatial zoning laws to curb unregulated borehole clustering and for implementing compulsory, routine water quality sampling procedures to address the sub-county’s deep-rooted geogenic fluoride crisis.
The scope of this study is strategically bounded geographically, conceptually, and temporally to ensure a rigorous retrospective analysis. Geographically, the research focuses on Kajiado Central Sub-County, encompassing its five administrative wards: Purko, Ildamat, Dalalekutuk, Matapato South, and Matapato North. This region was selected due to its high density of active and abandoned groundwater assets and its historical vulnerability to falling water tables.
Conceptually, the study investigates the economic viability of solar water pumping technology in comparison to diesel and grid systems, examining how spatial borehole clustering impacts static water levels. Additionally, it evaluates public health compliance by mapping ambient groundwater fluoride concentrations against safety standards.
Temporally, the study covers a ten-year horizon from 2015 to 2024 and relies exclusively on historic secondary datasets available as of December 2024. No projected or preliminary data for 2025 are included; all analyses are grounded in completed annual records sourced from established borehole registers, hydrogeological logs, sub-county financial audits, and public health archives. This study provides a comprehensive retrospective assessment while explicitly omitting primary field data collection or direct laboratory testing.
To address the systemic vulnerabilities of rural water transitions in Kenya’s arid and semi-arid lands, this baseline study investigates community-managed solar water pumping technology in Kajiado Central Sub-County through an ex-post retrospective lens. Grounded in a dual theoretical synthesis of Common-Pool Resource (CPR) and Socio-Technical Systems (STS) paradigms, the study fulfils three interconnected objectives:
First, it traces the ten-year hydrogeological footprint of uncoordinated borehole clustering, determining how free solar energy influences communal over-extraction and shifts static groundwater baselines.
Second, it examines the public health safety gap of this clean energy transition by auditing historical compliance records for geogenic fluoride contamination ( (Author, 2017)), illustrating the danger of unmonitored solar systems pumping water that significantly exceeds safe limits.
Finally, it analyses the economic tradeoffs of solarization by comparing its long-term operational savings against conventional diesel and grid systems, directly measuring how local water committee governance and tariff collection influence the system’s financial survival.
Safe water is not readily accessible in Kajiado County; communities depend heavily on surface water, shallow wells, and boreholes with hand pumps. Although boreholes are the principal water technology in both urban, peri-urban, and rural areas, gravity-fed piped systems are also available in some locations. Water security should be embraced through intra-sectoral integration of land-use and water management, supporting resource-efficient, integrated land–water–forest strategies at the micro-level decision-making programme level ( (Villamayor-Tomas & Kirk, 2019)). This is a holistic approach requiring cooperation across households, communities, and the national level, to safeguard vulnerable water sources and implement water-saving technologies that provide water equitably.
Improving access to water does more than delay the onset of diseases; it delivers important socioeconomic advantages that directly influence social decisions beyond health matters. These benefits are largely felt by women, who lose time, lift heavy loads, and risk injury carrying water over long distances; when the distance between them and their water source is shortened and water quality is maintained, quality of life improves substantially. Being able to secure reliable water access ultimately becomes a stepping stone toward community development and improved livelihoods—a goal that is impossible without safe and dependable supply ( (Odeh & Norton, 2006)).
Photovoltaic pumping (PVP) is a highly sustainable, cost-effective method for water extraction. Solar-powered irrigation has the potential to boost incomes, especially for remote agricultural producers, due to the significantly reduced cost of solar panels and the low maintenance requirement and long operating life of photovoltaic systems ( (Behbehani et al., 2009)). The use of clean, reliable sources of fresh water for rural areas is critical, and accurate technology for groundwater abstraction is essential since groundwater constitutes the primary water source in these areas ( (Parker et al., 2009)). For such areas, photovoltaic systems are the most efficient, economically suitable, and environmentally friendly technologies compared with fossil fuel and grid electricity alternatives.
In addition to introducing energy into the developing world, this technology also provides an important level of resilience in the event of rainfall changes resulting from climate change ( (Firatoglu & Yesilata, 2004); (Cloutier & Rowley, 2020)). Some governments provide support by subsidizing SWP systems to create a common knowledge base. Nonetheless, the advantages of solar pumping remain largely unknown to mainstream institutions, governments, and local communities. This critical unexplored awareness has direct impacts on climate adaptation in highly climate-sensitive locations such as Kajiado County, where traditional farming and pastoral livelihoods reliant on climatic conditions are gradually being compromised by climate change ( (Author, 2023)).
During the 2020–2023 drought, the devastating effects of this climate crisis were acutely realized in Kajiado County, where critical water and pasture resources were at high risk, threatening pastoral survival ( (Sturman & Quénol, 2023)). This environmental stress led to major child nutritional problems and forced alterations to traditional nomadic ways of life. According to local steering group reports, the number of children under five admitted to supplementary feeding programmes rose thirteenfold in July 2022. Apart from mass livestock deaths, agricultural harvests deteriorated and conflicts between people and wildlife over scarce resources intensified.
Methodologically, this study implements a comparative retrospective ex-post facto research design to assess the long-term viability of solar water pumping (SWP) systems. Rather than relying on cross-sectional observations, this framework evaluates mature SWP assets that have been operational for two to ten years post-installation, benchmarking their performance against a control group of newly commissioned systems. The control group of newly commissioned systems was selected using the following matching criteria: (i) geographic proximity within the same administrative ward or sub-ward; (ii) comparable borehole depth (within ±30 m of the corresponding mature system); (iii) similar aquifer characteristics (confined or unconfined), as documented in WRA drilling logs; and (iv) comparable user population size, defined as communities of 500–3,000 persons. This matched dual-cohort approach allows for a rigorous assessment of real-world equipment degradation, long-term community adaptation, and actual operational lifespans without manipulating any underlying environmental or institutional variables. The comparators in this design are diesel-powered versus solar-powered borehole systems, and pre-solarization versus post-solarization operational periods within the same sites.
To capture the complex operational dynamics of these systems, the research design synthesizes Common-Pool Resource (CPR) and Socio-Technical Systems (STS) theories. This theoretical integration addresses the inherently paradoxical nature of modernized rural water points, framing the solarized borehole simultaneously as a sophisticated mechanical installation governed by engineering parameters, and as a vulnerable public good whose survival depends on collective action, rule enforcement, and institutional resilience.
To analyze the socio-technical and environmental impacts of clean energy transitions in Kajiado Central Sub-County, this study utilizes an ex-post facto research design. This non-experimental framework is ideal because the primary interventions—the solarization of communal water assets and the accelerating clustering of localized boreholes—unfolded naturally over a ten-year horizon spanning 2015 to 2024. All secondary data used in this study are drawn from completed, verified annual records available as of December 2024; no projected or preliminary 2025 data are incorporated into the analysis. Where secondary data sources reflect reporting bias or missing variables (for example, gaps in quarterly health registry submissions), these limitations are explicitly acknowledged in the relevant results subsections.
A key justification for this design is the structural impossibility of variable manipulation. Acting as external observers, the research team could not control where private or public entities drilled boreholes, when solar arrays were integrated, or how geogenic fluoride fluctuated within the deep aquifer layers. Instead, the methodology relies on a retrospective analysis of a ten-year secondary dataset to isolate statistical relationships and model long-term trends. By pairing this longitudinal data with modern analytical tools, the ex-post framework supports robust cause-and-effect inferences, mapping how independent variables like free solar power and spatial density drive critical dependent outcomes such as reduced water retail costs, accelerated aquifer drawdown, and elevated public health fluorosis rates.
Table A: Synthesis of the Theories within the Energy–Water–Health Nexus
Theory | Primary Variable | Study Dimension | Operational Outcome |
(i) CPR | Aquifer sustainability/Well Density | Environmental Governance | Localized extraction by-laws & institutional compliance |
(ii) STS | Solar & Filter integration/user nodes | Technological, structural & carbon reduction | Financial scaling & reduced fluorosis rates |
To capture the complex interplay between clean energy, groundwater dynamics, and community governance, this study constructs a dual-theoretic model combining Common-Pool Resource (CPR) Theory and Socio-Technical Systems (STS) Theory ( (Abbas & Michael, 2026)).
Grounded in (Ostrom, 1990) foundational work, and informed by more recent CPR scholarship on solar-powered groundwater extraction ( (Villamayor-Tomas & Kirk, 2019); (Meinzen-Dick & Di Gregorio, 2018)), CPR theory is applied to Kajiado Central’s groundwater, which faces severe subtractability and theoretically low excludability under free solar pumping conditions. Empirically, the low excludability of groundwater in this context reflects the absence of enforceable physical or institutional barriers to borehole drilling within the sub-county, as documented in WRA permit records and confirmed by the observed clustering of unregistered boreholes identified in the Kajiado County Water Asset Management Dashboard. To evaluate how the sub-county can avoid a localized ‘Tragedy of the Commons,’ the study operationalizes four core design principles: boundary clarity to define user groups, congruence to align pumping limits with aquifer recharge rates, collective-choice arrangements to empower Water User Associations (WUAs), and conflict resolution mechanisms to mitigate resource disputes between domestic users and pastoralists.
Concurrently, STS theory frames the solarized borehole as an interconnected network of physical and human variables. The technical subsystem maps engineering inputs like PV degradation, inverter efficiencies, and borehole yields, while the social subsystem tracks human behaviors, institutional water needs, community financial readiness-to-pay, and local technical literacy.
Synthesizing these two theories yields a comprehensive framework capable of diagnosing systemic vulnerabilities. This integration demonstrates that infrastructure sustainability is fundamentally holistic: a system failure is rarely an isolated mechanical event, such as a blown inverter, but is instead rooted in institutional breakdowns like uncollected maintenance fees or unmanaged social competition at the pumping site.
Secondary data points were harvested across a ten-year timeline (2015–2024) from authoritative sector repositories. The Kajiado Water Asset Registry serves as a primary data source; this registry is maintained by the Kajiado County Department of Water, Environment, and Climate Change, updated on a quarterly basis, and covers all registered and monitored water supply systems within the county. Its completeness is assessed against the WRA permit database; any discrepancies between the two sources are flagged and resolved using sub-county hydrogeological survey records.
Table B: Secondary Data Extraction Matrix (Kajiado Central Sub-County)
Data Category | Specific Indicator | Unit of Measurement | Historical Data Range | Secondary Source |
(a) Borehole Profile & Tech | (i) No. of registered boreholes (ii) Pumping power source (iii) System status | Count; status-type: (i) Solar/diesel/grid (ii) Active/defunct/dry | 2015–2024 | (i) Kajiado County Water Asset Management Dashboard (ii) WRA – Water permit database |
(b) Spatial Dynamics | (i) GPS Coordinates/Mapping (ii) Inter-borehole distance | Arc-degrees to meters (m) | 2018–2024 | (i) Sub-county hydrological surveys (ii) GIS data repository |
(c) Economic Metrics | (i) Capital expenditure (CapEx) per borehole (ii) Monthly fuel/grid cost (OpEx) (iii) Consumer water tariff | (i) KES in millions per borehole (ii) KES/month (iii) KES per 20 L jerrycan | 2015–2024 | (i) Water service provider (WSP) audits (ii) Sub-county finance records |
(d) Environmental Metrics | (i) Static water level (ii) Dynamic water level (iii) Estimated aquifer yield | (i) Meters (m) (ii) Meters (m) (iii) Cubic metres/hour (m³/h) | 2010–2024 † | (i) WRA monitoring stations (ii) Borehole drilling logs |
(e) Public Health Profiles | (i) Fluoride concentration (ii) Total dissolved solids (TDS) (iii) Documented fluorosis cases | (i) mg/L (ii) mg/L (iii) Annual clinical count | 2015–2024 | (i) MoH reports (ii) Kajiado County Referral Hospital |
† Environmental baseline data commence from 2010 to enable pre-study hydrogeological benchmarking prior to the main 2015–2024 study window. This earlier data range does not imply that the study period extends before 2015.
Data were analyzed using two complementary analytical approaches. For quantitative trend analysis, the Mann–Kendall non-parametric test was applied to detect monotonic trends in fluoride concentrations, static water levels, and operational costs across the study period, given its robustness to non-normal distributions and missing data points typical of secondary environmental datasets. Linear regression was additionally employed to quantify rate-of-change relationships between key variables, including the relationship between borehole density and aquifer drawdown rates, and between solar adoption rates and operational cost reductions.
Thematic analysis was applied to qualitative secondary data sources, including policy documents, audit reports, and institutional records from the WRA, the Kajiado County Ministry of Water, and the Kajiado County Referral Hospital. A predefined codebook organized findings into three primary themes: (i) economic performance, covering tariff structures, CapEx recovery, and OpEx trajectories; (ii) environmental governance, covering extraction regulation, aquifer monitoring, and spatial planning compliance; and (iii) public health compliance, covering fluoride exceedance rates and documented fluorosis incidence. Codes were applied systematically and independently reviewed by two co-authors to ensure inter-coder consistency; any coding discrepancies were resolved through consensus discussion.
Classified as a water-deficient zone, Kajiado County presents a challenging environment where pastoralist livelihoods are highly sensitive to extended droughts. Low-income households are severely impacted, absorbing high water costs from local vendors while being forced to restrict their consumption to less than half of the WHO-recommended 20 liters per person per day. Data from the Kajiado Water Asset Registry—maintained quarterly by the Kajiado County Department of Water, Environment, and Climate Change and cross-referenced against the WRA permit database—reveals that approximately 35–40% of community boreholes are non-functional or experiencing operational disruptions at any given time, compared to a regional benchmark of 25–30% for comparable ASAL counties. As global fuel prices fluctuate, local water committees frequently exhaust operating capital, forcing residents to trek long distances to find alternative water sources. The Kajiado County Renewable Energy Atlas, however, outlines a favorable counter-narrative: high local solar exposure aligns perfectly with peak seasonal water demands, offering a sustainable transition with a typical financial break-even point of five years.
Demographically, water demand varies sharply across the sub-county’s five wards. Dalalekutuk, Matapato South, and Matapato North represent high-density consumer clusters placing sustained pressure on local water delivery systems, highlighting a critical need for high-volume pumping and expanded storage. In contrast, the rural and sparsely populated Purko Ward faces an immediate crisis whenever an infrastructure breakdown occurs, as isolated families live far from alternative options. This disparity requires a dual-track strategy: high-volume output for dense wards, and high-reliability, wide distribution networks for rural zones.
Currently, the 27 baseline borehole sites rely on infrastructure powered by high-emission diesel generators and outdated solar arrays. This creates two distinct operational challenges. First, ‘the diesel trap’ drains community funds through the continuous purchase of fuel and oil, tying local water costs directly to volatile fuel markets. Second, the technical limits of existing solar equipment cause underperformance during periods of cloud cover or early morning and evening hours, illustrating an urgent need for modernized, climate-resilient solar infrastructure.
Table C: Baseline Indicator Matrix of Borehole Sites (Diesel vs Solar) in Kajiado Central
Ward | Borehole Sites – Diesel | Borehole Sites – Solar | Total Strategic Boreholes |
Dalalekutuk | 3 | 2 | 5 |
Ildamat | 2 | 3 | 5 |
Matapato North | 4 | 2 | 6 |
Matapato South | 1 | 5 | 6 |
Purko | 2 | 3 | 5 |
Total | 12 | 15 | 27 |
Contextual Notes: (i) Solarization Focus – to mitigate rising electricity costs and the unreliability of fuel during droughts, the county government through the FLLoCA programme has rapidly transitioned many diesel pumps to solar. Matapato South, being one of the drier pastoral areas furthest from power grids, features the highest number of solarized boreholes. (ii) Fuel Subsidies – despite solarization efforts, several older boreholes in Dalalekutuk, Ildamat, and Purko still rely on strategic fuel subsidies provided by the county government to maintain continuous water pumping during dry spells.
Empirical evaluations from 2015 to 2024 in Kajiado Central Sub-County confirm that solarizing local water infrastructure drastically reduces operational costs, thereby supporting community-based water management, sustainable sanitation, and localized decarbonization. Specifically, hybrid solar photovoltaic pumping technologies reduce operational expenditures (OpEx) by 60% to 75% relative to diesel generation, as documented in field assessments of solarized borehole systems across rural and peri-urban Kenya (SNV, 2022; (Aliyu et al., 2018)). Furthermore, public health registry data from Kajiado County Referral Hospital (2015–2024) confirm that over 70% of monitored groundwater sources in the sub-county regularly exceed the WHO 1.5 mg/L fluoride threshold ( (Author, 2017)). However, this technical success is undermined by two critical systemic threats. Hydrologically, the zero-marginal cost of solar pumping fuels an uncoordinated, spatially dense clustering of boreholes that threatens the Kajiado Rift aquifer with irreversible degradation. Publicly, widespread geogenic fluoride levels exceeding the WHO 1.5 mg/L threshold present a severe health crisis, causing widespread dental and skeletal fluorosis across local communities.
Resolving these interlocking energy, resource, and health challenges requires shifting from random borehole development to structured, data-driven interventions. To successfully leverage international climate grants and foster county-wide climate resilience, Kajiado must execute a coordinated SWPT upscaling strategy across rural, peri-urban, and urban zones. This expansion must prioritize strict adherence to the Kajiado County Water Master Plan, utilizing grant-funded hydrogeological mapping to enforce localized abstraction caps while mandating community-managed fluoride treatment infrastructure to safeguard public health alongside aquifer longevity.
Table D: Energy–Water–Health Nexus – Theory Comparison
Common-Pool Resource (CPR) Theory | Socio-Technical Systems (STS) Theory |
(i) Governs the aquifer as a shared resource subject to subtractability | (i) Integrates Solar Technology within community infrastructure |
(ii) Resource subtraction drives the need for extraction limits | (ii) Technical artefacts (solar arrays, kiosks) shape social behavior |
(iii) Exclusion dilemmas arise from zero-cost solar pumping | (iii) Social actors (Water Kiosk Operators, WUAs) govern the technical system |
(iv) Institutional by-laws and WUA governance provide the response mechanism | (iv) Infrastructure scale and alignment with pastoralist norms determines sustainability |
To comprehensively analyze the intersecting challenges of clean energy transitions, groundwater depletion, and public health, this study utilizes a dual theoretical framework combining Common-Pool Resource (CPR) Theory and Socio-Technical Systems (STS) Theory.
CPR theory—anchored in (Ostrom, 1990) and updated by (Villamayor-Tomas & Kirk, 2019) and (Meinzen-Dick & Di Gregorio, 2018) for contexts involving solar-powered groundwater extraction—is applied to address the hydrogeological ramifications of uncoordinated, clustered borehole drilling. Groundwater in the Kajiado Rift System represents a classic common-pool resource where excludability is practically limited, as evidenced by the density of unregistered boreholes in the area, and subtractability is exceptionally high. The framework captures how the zero-marginal cost of solar pumping accelerates a ‘Tragedy of the Commons’, illustrating the urgent need for institutional interventions like active Water User Associations and execution of the Kajiado County Water Master Plan.
Concurrently, STS theory is employed to examine the scaling of solar pumping technology across diverse demographic zones. By treating solarized boreholes as interconnected networks where technical components (such as PV arrays and filtration systems) are completely interdependent with human systems, STS shifts the focus from mere technology deployment to long-term sustainability. This approach ensures that technical upscaling is systematically bound to community capacity building, local maintenance training, and health-focused water monitoring, thereby fostering genuine, climate-resilient development.
The economic profile of solarized water pumping is defined by a sharp dichotomy between high upfront capital costs and long-term operational savings. Field data from solarized borehole systems across rural and peri-urban Kenya demonstrate that hybrid solar photovoltaic pumping technologies reduce operational expenditures (OpEx) by 60% to 75% relative to diesel generation (SNV, 2022; (Aliyu et al., 2018)). However, the initial capital expenditure (CapEx) is structurally unviable for isolated community self-financing, emphasizing a heavy reliance on external grants and public climate finances like FLLoCA.
Beyond the macro-economic metrics, the ten-year data reveal that long-term financial sustainability is intrinsically linked to local governance structures. From a Socio-Technical Systems (STS) perspective, the presence of trained water management committees serves as a primary driver of financial health. Communities that instituted formalized tariff schemes and provided basic technical maintenance training successfully accumulated financial reserves. In sharp contrast, regions lacking these localized social structures experienced protracted equipment downtime, as minor technical malfunctions went unrepaired due to a lack of immediate community capital.
Table E: Financial Comparison of Solar Water Pumping Systems vs Diesel Generator Systems
Financial Indicator | Solar Water Pumping Systems | Diesel Generator Systems |
(i) Initial financial expense (CapEx per borehole) | High (KES 195,000–455,000 including panels, pump & structure) | Low (KES 52,000–104,000 initial machine purchase cost) |
(ii) Fuel & Energy costs (OpEx) | Zero (utilizes free, abundant sunlight energy) | High & Variable (continuous diesel purchases tied to market rates) |
(iii) Maintenance Expenses | Minimal (occasional panel cleaning – solid-state electronics require rare intervention) | Frequent (requires regular oil changes, filter swaps coupled with mechanical repairs) |
(iv) Estimated payback period | 1.5 to 3 years (system self-pays through eliminated fuel expenses) | Continuous expense (never reaches a financial break-even point) |
(v) Asset operational lifespan | Long (panels last 20–25 years; pump runs 5–10 years) | Short (typically 3–5 years due to heavy mechanical wear and tear) |
The structural architecture of a standardized Solar Water Pumping Technology (SWPT) system relies on five interlinked engineering subsystems. Power generation begins at the photovoltaic (PV) solar array, which converts raw solar irradiance into Direct Current (DC) electricity. This energy is regulated by the solar pump controller and inverter, which applies Maximum Power Point Tracking (MPPT) to dynamically align the system’s electrical output with the variable operational demands of the motor. The mechanical extraction is executed by a submersible pump assembly, uniquely suited for Kajiado’s deep aquifer depths, which forces groundwater to the surface. Fluid transport is managed via high-durability high-density polythene (HDPE) or PVC piping, designed to handle pressure shifts without structural failure. Finally, the system uses a gravity-fed storage reservoir to ensure water availability during non-sunlight hours, avoiding the need for costly battery banks for water supply continuity; it should be noted that while this reservoir stores water as potential energy for gravity-fed distribution, it does not store electrical energy and should not be conflated with an electrical energy storage device.
Table F: Baseline Indicator Matrix
Evaluation Indicator | County Baseline Value | Source Agency | Data Year |
Safe water access rate | 35%–45% of the county population | Kajiado County EPI | 2022 |
Dry season water trek distance | 4.5 km to 10.3 km | Journal of CMSD / Ministry of Water | 2022 |
Per capita water availability | 162 m³/annum (vs. 600 m³/annum national average ‡) | Wetlands International / Government of (M & I, 2020) | 2020 |
Off-grid solar market penetration | 32%–35% – low | Baseline Report – Household Energy & Indoor Air Quality Study, Ministry of Energy | 2019 |
Solar resource availability | 5.5–6.0 kWh/m²/day | Kenya Solar Resource Mapping Project / ALIN | 2020 |
Average cost of informal water | KES 10 per 20 L jerrycan (KES 500/m³) | Kenyatta University Institutional Repository | 2023 |
Average aquifer depth (boreholes) | 100–250 metres | University of Nairobi Groundwater Potential Studies | 2021 |
Note: Baseline data from 2019–2023 may not reflect current conditions; trends should be interpreted with caution and cross-referenced with the most recent available sub-county monitoring data. ‡ The national average of approximately 600 m³/annum per capita is sourced from FAO AQUASTAT ( (FAO, 2023)) and represents the renewable freshwater available per capita per year in Kenya; readers should note that actual accessible water per capita may differ substantially due to infrastructure and distribution constraints.
‡ Full reference: Wetlands International and Government of (M & I, 2020). Kajiado County Water Resources Profile. Nairobi: Wetlands International Africa.
Our findings show that solar water pumps in Kajiado Central Sub-County significantly lower operational costs and retail water prices by shielding users from volatile fossil fuel markets. However, the zero-cost nature of solar power creates an incentive to pump water continuously without restriction. This overuse, compounded by densely clustered boreholes and weak regulatory enforcement, threatens long-term water sustainability.
Furthermore, our results reveal a critical public health gap in current energy transitions: groundwater sites frequently exhibit geogenic fluoride levels that far exceed WHO safety limits ( (Author, 2017)). Consequently, ‘clean technology’ alone cannot guarantee true sustainability. To prevent a renewable energy solution from precipitating an environmental and public health crisis, technical innovation must be paired with strict hydrogeological limits, community-led abstraction caps, and mandatory water treatment infrastructure. Moving forward, data-driven mapping and coordinated borehole management are vital to transition from random drilling to a climate-resilient water network that protects both aquifer longevity and public health.
To secure long-term climate resilience, the County Government of Kajiado must prioritize the coordinated upscaling of Solar Water Pumping Technologies (SWPT) across rural, peri-urban, and urban demographic zones. A primary focus should be retrofitting older, high-maintenance diesel and electric boreholes to provide rapid, affordable water access to remote communities, thereby advancing current green initiatives like the FLLoCA programme. However, technical upscaling must be balanced with data-driven and community-led resource protection. By leveraging international climate grants, the county should fund detailed hydrogeological mapping to establish extraction limits and prevent aquifer depletion. Crucially, these investments must be anchored by a bottom-up approach that establishes trained community water committees. Integrating robust local governance with scientific mapping will ensure that decarbonizing Kajiado’s water network yields lasting benefits for public sanitation, small-scale agriculture, wastewater recycling, and environmental preservation.
Funding: This research was supported by institutional funds from Umma University. The authors declare no other external funding.
Acknowledgments: We are indebted to Umma University for providing institutional funds to undertake the baseline study.
Conflicts of Interest: The authors declare no conflict of interest.
Data Availability Statement: Data supporting the findings of this study are available from the Kajiado County Ministry of Water, the Water Resources Authority (WRA), and Kajiado County public health registries upon reasonable request. Restrictions apply to the availability of these data, which were used under license for this study. Data are available from the authors upon reasonable request and with permission of the relevant authorities.