North–Central Namibia region is faced by absolute water scarcity. The Calueque-Oshakati canal conveys potable raw water to the region from the Kunene River in southern Angola. The canal is exposed to pollution due to human activities. The objectives of this study were to assess pollution trends along the canal and to determine its impact on chemical requirements for the four water treatment plants abstracting water from the canal. Water samples from the canal were analyzed for selected parameters and jar tests were carried out at the treatment plants from February to April 2008. An increase in parameter concentration in the canal was observed from upstream to downstream. The most upstream plant had average experimental coagulant and actual chlorine dosages of 20 and 3.5 mg/l respectively compared to 45 and 7.7 mg/l for the most downstream plant. It was concluded that pollution, which increased along the canal increased the chemical requirements for water treatment.