Journal of Water Resources, Engineering, Management and Policy

Infrastructure condition index assessment of water supply systems in rural Tanzania: A case study of Namtumbo and Rwinga wards

2026-04-13T15:54:54+00:00

This study addresses the critical knowledge gap in systematic assessment and maintenance of existing rural water infrastructure in “sub-Saharan Africa,” where other studies focused primarily on access expansion rather than condition monitoring of operational systems. A comprehensive Infrastructure Condition Index (ICI) assessment method was employed in Namtumbo and Rwinga Wards, Tanzania, utilizing systematic field surveys, technical evaluations of storage tanks, intake structures, and pipeline networks. Statistical analysis was conducted using Microsoft Excel with Data Analysis ToolPak and R Statistical Software for descriptive statistics, weighted averages, and box plot visualizations. Results revealed alarming infrastructure deterioration with an overall average ICI score of 3.2, categorizing most facilities as "Poor" condition. Critical findings include the severely affected Minazini storage tank (ICI: 2.1) with 15-20% capacity loss, aging 46-kilometer pipeline network with 30% unaccounted-for water losses, and structural failures requiring emergency intervention. The study recommends implementing an immediate emergency rehabilitation program with US$ 2.5–7.3 millions or Tsh.6.250-18.250 billions funding allocation, establishing systematic infrastructure monitoring frameworks, and strengthening institutional capacity for evidence-based maintenance prioritization. This research provides a replicable methodology for rural water infrastructure assessment in Tanzania, aligning with Vision 2050, SDG6, and Africa's Agenda 2063, demonstrating proactive management's economic viability.

Profitability analysis of paddy farming systems in wetland areas, Kilombero, Tanzania: An additional layer to curing maladaptation

2026-04-13T15:57:04+00:00

Agriculture contributes 28.9% of Gross Domestic Product; about USD 1 Billion to total export value and employs about 65 % of Tanzanians. Identifying opportunities for enhancing profitability of the sector is paramount to informing choices of sustainable pathways. In the absence of such information, maladaptations are likely to be perpetuated. This paper investigated profitability of paddy farming both rainfed and irrigated systems using participatory rural appraisal approaches. It studied the mechanized and small holder practices such as, the conventional transplant and flooding system (CTFS) and system of rice intensification (SRI). Findings demonstrated that; (a) although smallholder farmers use least inputs and technology, harvested an average of 1.33 Tons/Ha more than the mechanized irrigated system under Kilombero Plantations Limited. However, owing to better economies of scale and stable markets, the latter was more profitable (b) increased harvest due to irrigation in small holder farms is less than 10% of their respective rainfed systems which suggests that rainfed system is more plausible in the case study (c) rainfed SRI harvests 73% more than rainfed CTFS. It is therefore recommended to promote rainfed SRI and grouping farmers at manageable scale to foster a better scale of economy, price negotiation basis and hence better profitability score.

Numerical evaluation of the Mtibwa sugar estates earthfill dam safety, in Turiani- Morogoro, Tanzania

2026-04-13T15:59:45+00:00

Earthfill dams are vital for water supply, irrigation, and flood control, but their safety can be threatened by structural weaknesses and poor maintenance. This study evaluates the safety of the Mtibwa Sugar Estates Earthfill Dam in Turiani, Morogoro Region that supports irrigation and economic development but limited monitoring raise stability concerns, necessitating safety measures to protect livelihoods. The assessment combined field reconnaissance, geotechnical laboratory testing of dam materials, and numerical modeling using GeoStudio 2023.1. Seepage through the embankment was analyzed using SEEP/W, while slope stability was assessed with SLOPE/W. Results showed soil permeability ranging from 2.25×10^⁻¹⁰ to 1×10^⁻² m/s, cohesion between 0 and 173 kPa, friction angles of 9.28°–38°, and moisture contents of 10%–30%. These values indicate a clay core with low permeability suitable for seepage control, supported by shell and drain materials that allow adequate drainage. Variations in strength parameters reflect both weak clayey and stronger sandy layers, influencing stability. Seepage discharge was 4.54×10^⁻⁶ m/sec, while slope stability analysis yielded a factor of safety of 1.566, confirming stable slopes. The study recommends improved drainage, monitoring systems, periodic stability assessments, and stronger dam safety management.

Optimizing water supply efficiency: Enhanced management strategies and implementation framework

2026-04-13T16:01:56+00:00

Despite global infrastructure investments, tropical coastal water distribution systems experience 30-40% losses, exceeding the 15% international benchmark, due to inadequate static optimization models failing to capture dynamic interdependencies between infrastructure deterioration, environmental factors, and operational parameters. This research develops an innovative multi-dimensional predictive framework integrating infrastructure deterioration modeling with real-time pressure dynamics and seasonal patterns using machine learning and hydraulic modeling. The methodology employed a mixed-methods data collection approach from the Kunduchi water supply network, incorporating structured surveys of 35 technical staff with quantitative operational measurements, followed by multiple linear regression analysis and rigorous model validation using normality distribution analysis, multicollinearity assessment, and homoscedasticity testing. The developed model explains 84% of efficiency variance through four key predictors: pipe class (β =-15.21), pipe age (β =-0.48), operating pressure (β =4.15), and age-class interaction effects (β = -0.238), revealing that Class C pipes comprising 55.6% of the network account for 76.2% of repairs, while seasonal variations increase water losses by 34-38% during rainy periods. Research shows 18-24% efficiency gains via integrated modeling of water systems with non-linear interdependencies. This scalable methodology achieves SDG 6 targets through enhanced system efficiency rather than infrastructure expansion.

Assessment of heavy metal contamination in urban tributaries draining into Lake Victoria at Musoma and Tarime towns, Tanzania

2026-04-13T16:03:41+00:00

Water contamination by heavy metals poses serious environmental and public health threats, particularly in urban and agricultural regions where human activities intensify pollution. This study aimed to determine the levels of heavy metal contamination in urban tributaries along Musoma and Tarime towns to safeguard aquatic ecology and public health. Seventyeight water samples were collected from twenty-six strategically selected sites across the two urban areas. Physicochemical parameters (pH, EC, TDS, turbidity, and temperature) were analyzed on-site using the potentiometric method, while heavy metals (Hg, As, Cr, Pb, Cd, Zn, and Cu) were determined using ICP–OES. Results showed wide spatial variations with pH (7.3–8.94), EC (94–3900 μS/cm), TDS (56–2360 mg/L), turbidity (9.4–2098 NTU), and temperature (22.4–27.8 °C). Metal concentrations ranged from Pb (0.005–0.082 mg/L), Cd (0.002–0.019 mg/L), Cr (0.004–0.021 mg/L), As (0.0003–0.001 mg/L), Cu (0.006–0.118 mg/L), Zn (0.032–0.264 mg/L), and Hg (0.0001–0.0004 mg/L). Pb and Cd Concentrations exceeded WHO drinking water limits, suggesting contamination from mining and domestic discharges. Overall, findings reveal moderate but spatially variable contamination, highlighting the need for continuous monitoring, stricter pollution control, effective remediation to protect water quality in the Lake Victoria Basin.

Optimizing chlorine decay factors in intermittent water supply using box-behnken design

2026-04-13T16:05:49+00:00

Chlorine decay in water distribution systems is a critical challenge that impacts disinfection efficiency and public health. Using the Box-Behnken Design this study systematically investigates the effects of pH, flow rate, pipe length, and stagnation time on chlorine residual loss through a controlled experimental framework and optimize them to maintain acceptable residual chlorine. Analysis of Variance (ANOVA) was performed and revealed that pH and stagnation time were the most significant factors. Lower pH less than 7 and longer stagnation of over 2 hours accelerated chlorine decay by up to 40%. Flow rate showed a secondary but notable effect, where higher velocities (1.0 L/min) reduced decay by 15 to 20%. A quadratic model (R^² = 0.98) demonstrated strong predictive accuracy and revealed key interactions between initial chlorine dose and pH. At optimized conditions, a target residual chlorine level of 0.34 mg/L was achieved, balancing disinfection and operational efficiency. This study offers a vital strategy for utilities to mitigate the public health risks associated with inadequate disinfection in distribution networks.

To establish economic viability of District Metered Areas: A case study of DAWASA’s Kinondoni Service Area, Tanzania

2026-03-30T21:59:54+00:00

District Metered Area (DMA) systems promoted as a strategy for reducing Non-Revenue Water (NRW) and improving operational efficiency in urban water supply networks, yet their financial viability in Sub-Saharan Africa remains uncertain. This study assessed the economic feasibility of implementing 13 DMAs in Kinondoni Service Area under the Dar es Salaam Water Supply and Sewerage Authority (DAWASA) between 2023 and 2025. Using a cost benefit framework that combined Capital Expenditure (CapEx), Operational Expenditure (OpEx), and Net Revenue Gain (NRG), four indicators, Return on Investment (ROI), Cost-Benefit Ratio (CBR), Payback Period (PP), and Financial Sustainability Index (FSI) applied. Results showed poor short-term viability (ROI −96.5%, CBR 0.035, PP 23.1 years, FSI −0.797), driven by high initial costs and modest revenue gains. Scenario analysis identified NRG as the most decisive factor for financial recovery. The study concludes that DMA investments are not currently financially sustainable, but phased implementation in high-NRW zones, supported by tariff reform and donor cost sharing, could improve long-term economic viability. These findings provide important guidance for DAWASA, regulators, and development partners in designing policies and financing models for sustainable water supply management.

Stakeholders' engagement in planning and monitoring the performance of water supply projects at Songea Water Supply and Sanitation Authority

2026-04-13T16:08:32+00:00

This study assessed stakeholder engagement in planning and monitoring the performance of water supply projects at the Songea Water Supply and Sanitation Authority (SOUWASA) in Tanzania. Employing a mixed-methods research design, the study combined both quantitative and qualitative approaches. Data were collected from 91 SOUWASA staff, community representatives, and local government officials, selected through simple random and purposive sampling. Quantitative data were analysed using descriptive and inferential statistics, including regression analysis, while qualitative data were examined through thematic analysis. The results show that stakeholder participation, communication mechanisms, and conflict resolution significantly influence project performance at the 5% level (p < 0.05). Among these, conflict resolution had the strongest effect. Effective engagement was found to enhance coordination, reduce delays, and align project objectives with community needs, ultimately improving project performance. However, qualitative evidence indicated inconsistencies in depth and continuity of engagement, often undermined by declining interest, weak communication, and conflicting priorities. The study concludes that while stakeholder engagement positively impacts project outcomes, its effectiveness depends on being continuous and inclusive throughout the project lifecycle. Strengthening communication, building stakeholder capacity, and formalizing conflict resolution are critical to enhancing project success and sustainability.

Evaluating the effectiveness of Water Sensitive Urban Design (WSUD) measures in reducing runoff at the water institute in Dar es Salaam, Tanzania

2026-03-30T22:01:33+00:00

Rapid urbanization in cities like Dar es Salaam has led to increased stormwater runoff due to expanding impervious surfaces and insufficient drainage systems. The Water Institute, one of the region’s fastest-growing institutions, is also experiencing these pressures. This study investigates the effectiveness of Water Sensitive Urban Design (WSUD) measures such as bioretention ponds, rain gardens, rain barrels, and infiltration trenches at the Water Institute (WI) using the Storm Water Management Model (SWMM). A Digital Elevation Model (DEM) and ArcGIS 10.4 were used for topographic and hydrological analysis, while soil infiltration capacity was measured in the field using a Guelph permeameter, which indicated rates ranging from 1.6 to 14.9 mm/hr. Simulations revealed that combining multiple WSUD measures could reduce stormwater inflows into the drainage system by up to 68.2%, indicating substantial reduction in surface runoff volumes generated from impervious campus areas. These findings underscore WSUD’s value in managing urban runoff, promoting sustainability, and highlight the need for broader application across the Dar es Salaam and other rapidly urbanizing cities.

Evaluating socio-cultural roles in behavioural adaptation for sustainability of rural water supply for climate change intervention. A case study of Sangara Village, Babati District, Manyara Region, Tanzania

2026-03-30T22:05:25+00:00

Climate change significantly threatens rural water supply infrastructures, compromising water quality and availability while increasing community vulnerability. This study evaluated socio-cultural roles in behavioural adaptation for sustaining rural water supply for climate change intervention. The analysis was conducted using the RANAS model, a behavioural change framework where data collection methods were Household surveys, Interviews and Focus Group Discussions. The findings were: 70.7% of respondents never engage in tree planting while 95.9% cut trees for charcoal production. Most participants (91.2%) consider charcoal the low-cost energy source, and 56.7% prefer cooking with firewood. The 76.3% recognize agriculture's environmental degradation and 73.1% acknowledge environmental protection norms where behaviours remain counterproductive to intervention for environmental sustainability while 82.3% support integrating scientific knowledge with traditional practices in climate adaptation. The community behaviours largely oppose climate change intervention sustainability thus calling the Government and Non-Governmental Organizations for need and applying behavioural change to sustainable access to safe drinking water, sanitation, and hygiene.

Understanding behavioral factors linked to pollution and water quality in Lake Bassotu

2026-03-30T22:07:54+00:00

Water security in rural Tanzania is endangered not only by environmental pressures but also by the behaviors, perceptions, and norms shaping everyday water use. This study applied the RANAS model of behavior change to assess behavioral drivers of water insecurity in Lake Bassotu, complemented by water quality analysis. Data collection included household surveys (n = 384), key informant interviews (n = 7), structured observations, and laboratory testing of ten water samples. Quantitative data were analyzed using SPSS (descriptive statistics, chi-square tests, logistic regression), while qualitative data were thematically coded in NVivo. Results revealed while 80.6% of households depend on Lake Bassotu, 77.3% perceive it as unsafe. Yet only 4.9% practice water treatment and 17.5% engage in pollution control, revealing a wide awareness–action gap. Regression analysis demonstrated that risk perception and positive attitudes significantly predicted protective behaviors, whereas weakened social norms and limited abilities reduced engagement. Laboratory findings of high turbidity (126–214 NTU), alkaline pH (9.1–9.3), and microbial contamination (66–95 CFU/100 mL) validated community concerns but underscored behavior, not awareness, as the critical barrier. Strengthening community norms, enabling actions, and linking behavioral change with governance enforcement are essential to safeguard Lake Bassotu’s water security.

Legal landscape analysis of faecal sludge management in Tanzania: A technical perspective with lesson learned from Arusha city

2026-04-13T16:11:31+00:00

The race of attaining adequate sanitation services by 2030 remains a myth in Tanzania since the faecal sludge management systems lags far behind wastewater management systems. The case should have been vice-versa since massive amount of faecal sludge is generated in urban settings as compared to wastewater. There are several setbacks that lead to the cause but this study explored the relevance of available policies, acts, regulations, guidelines, rules and standards in attaining adequate faecal sludge management in urban settings, taking Arusha city as a reference point for discussion. The review of legally binding document and key informant interviews were the methods used for data collection, that were further analyzed using the Strength, Weakness, Opportunities and Threats (SWOT) technique. The findings revealed that only 13% of the urban population in Tanzania is covered by sewer, leaving 87% under onsite sanitation systems (mainly the pit latrines and septic tanks) that generates massive amount of faecal sludge dislodged to municipal treatment systems. However, the reviewed policies, acts, regulations, guidelines, rules and standards, gives priority to wastewater management and mostly referring faecal sludge in same category as wastewater. This misleads the entire concept as it promotes use of wastewater management interventions which are not adequate in handling the generated faecal sludge. To remedy this, all stakeholders engaged in faecal sludge management from all levels should be convened to review the legally binding documents. Hence, ensure that the faecal sludge management is exhaustively covered, and that the roles and responsibilities for respective stakeholders are well defined to simplify and fasten projects implementations.

Ecological health assessment of Lukosi river using macroinvertebrate and riparian vegetation indicators in Iringa, Tanzania

2026-04-13T16:17:18+00:00

The health of river ecosystems is increasingly threatened by human activities such as agriculture, urbanization, and industrialization. This study evaluates the ecological status of the Lukosi River Catchment (LRC) in Kilolo District, Iringa, Tanzania, using macroinvertebrates and riparian vegetation as bioindicators. We employed a cross-sectional design, sampling at upstream, midstream, and downstream sites. Macroinvertebrates were collected via the kicking-bottom method and analyzed using the Shannon–Wiener diversity index and the Average Score Per Taxon (ASPT). Riparian vegetation was surveyed through belt transects and assessed by species distribution and proportional cover. Fourteen macroinvertebrate taxa were identified, dominated by water scavenger beetles and snails. Biodiversity was moderate (H′ ≈ 1.98). ASPT scores declined spatially: upstream (good quality), midstream (moderate), and downstream (poor), indicating worsening water quality downstream. The riparian zone was heavily modified: about 58% grasses, 28% shrubs, and 14% trees, reflecting human disturbance and land-use change. The results reveal progressive ecosystem degradation along the river, strongest downstream, likely driven by pollution and catchment alteration. These results call for integrated catchment management policies, stricter land-use regulation, and community-based riparian restoration programs to enhance water quality, biodiversity, and long-term ecological resilience of the LRC.

Assessment of barriers to customer satisfaction in urban water service delivery: A case study of Ubungo District, Dar es Salaam, Tanzania

2026-04-13T16:19:50+00:00

Despite sustained investments in Tanzania’s urban water sector, challenges persist in ensuring consistent and high-quality service delivery, particularly in densely populated areas like Ubungo District, Dar es Salaam. This study uses a mixedmethods approach to investigate the key factors inhibiting customer satisfaction with water services in the district. Data was collected from 380 respondents where by 239 Ubungo residents and 141 DAWASA staff members also 11,710 service complaints retrieved from DAWASA’s CRM system. Quantitative data were analyzed using SPSS through descriptive statistics, Pearson correlation, and multiple regression, while qualitative responses were assessed thematically by content analysis and researcher interpretations. Results indicate that responsiveness to customer complaints (β = 0.464) and water supply reliability (β = 0.344) significantly influence customer satisfaction. Assurance also plays a minor but notable role (β = 0.127). Spatial analysis revealed pronounced inequalities in service delivery, with peripheral areas experiencing prolonged complaint resolution times and greater dissatisfaction. Thematic analysis highlighted four primary barriers: inconsistent water supply, technical infrastructure failures, delayed complaint responses, and limited customer education. The findings underscore the urgent need for systemic reforms, including improved complaint handling, infrastructure upgrades, and community engagement strategies. The study contributes actionable insights to enhance urban water utility performance and support evidence-based policy development in Tanzania and similar urbanizing regions.