Cost effective designs for rural water schemes

Water supply schemes for rural and urban fringe (periurban) communities generally cost more per capita than for urban communities in formal township layouts. The main reason for the increased cost is the lower population density in rural and urban fringe communities. Cost per capita is often the key criteria used to determine the feasibility of schemes. Consequently engineers are continuously under pressure to reduce the capital costs of water supply schemes to these communities by using more appropriate design standards. There are many established design standards that can be adjusted to suit the specific requirements of rural and urban fringe water supply schemes to effect a reduction in the capital costs of these schemes. Most will reduce the capacity of the scheme and can result in operation and maintenance problems. These problems nearly always result in increased operation and maintenance costs. This paper discusses the methods of reducing the capital costs in the design of rural water supply schemes, the implications of adjusting these design parameters and identifies design parameters that have a net positive effect on a scheme. It should be noted that community participation in agreeing to the standards discussed in this paper is essential to the success of the project. The communities must be informed why certain standards are adopted and how these will impact on them.