Use of engineering economic equivalence tenets to prioritize water source(s) for use by households, ‘The Case of Mbeya City – Tanzania’

Abstract

ABSTRACT In Tanzania, inadequate access to water affects 26% of urban and 38% of rural populations, who depend on piped water systems and are often subject to rationing. Low-income households face the significant burden of high water bills and (sometimes) poor water quality. Alternative water sources such as gravity-fed, rainwater harvesting, and drilled well systems are often overlooked, primarily due to the absence of evaluations based on engineering economic equivalence (EEE) principles that determine their viability due to prioritization. This study addresses this gap by analyzing existing literature and utilizing data from Mbeya City, focusing on households relying on tap water, rainwater harvesting, and drilled wells. Engineering Economic Equivalency computations were used to assess the present worth of these water sources, with values determined at Tshs 11,009,424/- for tapped water systems, Tshs 10,283,000/- for rainwater harvesting, and Tshs 12,099,940/- for drilled wells. While rainwater harvesting appears cost-effective, it was found unsuitable for drinking, and tapped water systems incur variable consumption costs. Consequently, the drilled well system is the most sustainable option for ensuring reliable household water access. Households in Mbeya are urged to deploy the engineering economic equivalence principle to prioritize their water-for-own-use.