Quantifying the nonrevenue water problem in a sub-Saharan African environment: a practical application in the Republic of Cameroon (Central Africa)

Abstract

A water distribution network faces a number of problems associated with its continuous aging process, including water loss. Nonrevenue water (NRW) is the water that is produced by a water utility but not sold to customers. This study aimed to update nonrevenue water (NRW) estimations in the water supply network in Cameroon to identify challenges in reducing the NRW in the country, as this approach is applicable in sub-Saharan African environments with similar affinity patterns. Data on water supply access in Cameroon were collected from the Joint Monitoring Program of the WHO and UNICEF, the IBNET, the Central Bureau of the Census and Population Studies of Cameroon, and the Demographic Health Survey. Microsoft Excel was used to assess the NRW volume based on the Wyatt/IDB methodology, including calculations of the supplied population, domestic consumption, nondomestic consumption, system input volume, and NRW. The results indicate that the global volume of NRW in the water supply network in Cameroon was 84.7 million cubic meters per year, including 82.4 million cubic meters in urban areas and 2.2 million cubic meters in rural areas. The cost/value of the water lost per year was 28.6 billion CFA francs (USD 47.6 million). This high level of water loss, particularly in urban areas, had an impact on the financial viability of the Camwater. Indeed, as of December 31, 2020, the liquidity ratio of 0.89 indicates that Camwater's activities do not generate enough cash to meet short-term commitments, while the solvency ratio of 2.2 indicates high long-term debt relative to the level of equity. By cutting Cameroon’s NRW to half its present level, approximately 1.2 million people could be supplied, including 1.1 million in urban areas and 100,000 in rural areas. The findings also suggest that a high level of NRW is influenced by rapid urbanization, outdated infrastructure, and a high level of poor operation and maintenance, including an ineffective record-keeping system and inadequate technical skills and technology.