Hydraulic ram pumps and Sling Pumps

OP-32-ERestoring defective schemes (rehabilitation) can provide an economic alternative to investment in newprojects, but that decision should not be automatic. Just as with a new scheme, the rehabilitationoption has to be evaluated by balancing community needs, preferences and its capacity to sustain theproject, with the potential for support by the water agency. In assessing scope for rehabilitation, thecommunity and the agency need to review together what made the system break down, analyse theproblems and recommend feasible technologies. Furthermore, rehabilitation should not simply be amatter of replacing broken equipment or infrastructure. The most common cause of failure isorganisational.If a risk analysis is carried out for each water supply option, an attempt can be made to anticipatefactors that may change and affect O&M. This will not be easy, especially in unstable economieswhere inflation and the availability of imported equipment and spare parts are difficult to predict. Acomparison of technologies can indicate the degree of risk attached to each option.It is difficult to find comparable and accurate data on recurrent costs. Indeed, recurrent costs varywidely from one project or country to another, in terms of what has been included in the calculations.Moreover there are large differences in wage, equipment and material costs. The data is only valid forthe context in which a particular project has been developed, but it can give an idea of the importanceof these costs.Another difficulty mentioned in reports, is deciding how to present recurrent costs, (e.g. cost per m 3 ,cost per capita, cost per year, cost per household). The most relevant way to present recurrent costs inthe context of community-managed water supply systems would be cost per household, sincehouseholds are the basic economic unit, and costs could be compared to affordability for eachhousehold. However, cost per m 3 can allow a better comparison between projects and countries, sincethe size of households and their consumption can vary greatly from one country to another.1.2.2 Aiming for equityWhat is the scope of equity ?“Something that is equitable is fair and reasonable in a way that it gives equal treatment toeveryone” 14 . In the context of community water supply equity implies that all social groups in acommunity can have access to the benefits of an improved water supply system, proportionally to theirbasic needs. The potential benefits of an improved water supply are as follows:• accessibility (both physically and financially),• convenience (comfort and cultural acceptance),• continuity (both in quality and in quantity),• impact (on health and possibly income generation).Financial accessibility means that the amount of water needed for drinking, cooking, essential hygieneand production of subsistence food should be affordable. By “all social groups of a community” wemean the rich and the poor, men and women. There are within communities several social groups thatare particularly vulnerable socially, economically and culturally. These groups are composed ofwomen (especially single heads of families), elderly people, people with disabilities, children, andindigenous groups.Everyone within the range of an improved service, whatever their social status or economic condition,should therefore be able to have access to its benefits, as water is recognised worldwide as a basichuman need. In some way, this already gives a social dimension to water supply, which planners anddecision-makers cannot deny. Recognising this means integrating a social dimension into a costrecovery strategy. This will require an ability to evaluate the needs and priorities of different socialgroups.14According to the Collins Cobuild English Dictionary10