Busari, Afis OlumideEino, Junias2026-03-252026-03-252025http://hdl.handle.net/11070/4243A thesis submitted in fulfilment of the requirements for the degree of masters of science in Civil EngineeringThe Namibian people, particularly those living within the Iishana system, which is a subset of the Cuvelai Basin, often encounter recurrent floods and droughts. After each rainy season, the Iishana system dries up gradually, hence, water for both agricultural and potable purposes becomes crucial. To enhance water availability, this study evaluated water demand and quality within the Namibian Iishana system, considering planned infrastructure developments and the rehabilitation of existing systems. This study employed a physical interaction, as well as the administration of questionnaires, to determine the population per-capita demand within the Iishana system. A thirty-year population projection was used to estimate future water demand. Moreover, the hydrological data (daily rainfall and temperature) from 2012-2021 were incorporated. As the water quantity and quality are inseparable, ten water samples were collected for Water Quality Index (WQI) and Multivariate Statistical Analysis using Minitab (21.2). The Piper diagram generated using Grapher (20.2.321) further classified water types. The current rural population and livestock water demand were estimated to be 2,479 and 4,282 m3 /respectively. Projected demand forecasts for 2033 (0.9 Mm3 /year), 2043 (0.5 Mm3 /year), and 2053 (0.1 Mm3 /year) indicate a declining trend, due to outmigration. More so, water availability is found to be affected by climate change, making it insufficient to meet demand. Climate data analysis showed a rising temperature trend, with annual precipitation (310 mm) far exceeded by evaporation (2,500 mm), resulting in water level drops and poor quality. The WQI scores (81.30-320.65) classified the water as unsuitable for human consumption. The Principal Component Analysis (APA) identified key influences: soil formation, mineral dissolution, microorganisms, and agricultural runoff. The Piper diagram classified 100 % of the sampled water as Na+ -K + water types, indicating salinisation. The water crisis in the area demands urgent, coordinated action to balance supply enhancement with quality control. Therefore, it is crucial to harvest flood and rainwater by expanding the size of natural pans in the study area for use during dry periods. Water treatment for pans can augment the water supply for the rural populationenPer capita demandRural populationIishana systemWater demandWater supplyInfrastructureWater qualityNamibiaUniversity of NamibiaThesis