Hydraulic ram pumps and Sling Pumps

OP-32-EAdvantages and disadvantages of a mixed system (house connections together with standpost)Conditions Advantages DisadvantagesSuitable where there isadequate demand for, andwillingness to pay for,household connections, andwhere poor households cannotafford individual connections." Offers consumers choice ofservice level" Rates reflect level of service" Poor can benefit from subsidisedor free basic service" May be difficult to optimise balancebetween house connections andstandpost" Higher rate payers may havedisproportionate influence overmanagement of the schemeSource: Adapted from Evans (1992)Water re-vendingWater may be obtained by small-scale vendor groups, or individuals, from private or municipal taps,and sold either from a public vending kiosk or sold door-to-door. In this system, users pay for water bycontainer or bucket purchased, at a price that is higher than the price paid originally. Profit marginscan be outrageously high, especially in low-income urban areas, where communities do not have analternative. Furthermore, the quality of water is not guaranteed through all these intermediary steps.The main disadvantage of water re-vending is its high price. Often users pay more for 20 litres ofwater with this system than those who are supplied 500 litres per day from a piped system(Whittington, 1989).Advantages or disadvantages of a mixed system (Water vending)Conditions Advantages DisadvantagesHigh demand for water;very little alternative inwater provision." Users buy the quantity of water at anegotiated price" Water distribution is easy" Users who live far from alternativewater sources can save time andeffort" Generation of employment anddemand of local products" Risk of pollution during watertransport and manipulation" Users pay high prices comparedwith the prices in water systemswith private taps" There are no rules and policiesfor regulationSource: Adapted from Evans (1992)2.1.2 Tariff calculationNon metered flat rates (See Annex 1 for example)As mentioned earlier, tariffs are linked to the costs of supplying and treating water. However, theamount is linked to a specific cost recovery strategy or is the result of a social policy. It is proposed todistinguish two types of tariffs: a) basic tariff; b) real cost tariff.Basic Tariff includes only the recovery of basic operation, maintenance and administration costs,called ‘functioning costs’. These costs are divided by the number of households.Basic Tariff = Functioning costs per monthNumber of householdsIf such a tariff is chosen it will be appropriate to consider with the community how the other costs willbe covered.Real Cost Tariff includes not only the functioning costs, but also replacement and extension costs,which have been estimated in this example as representing 25% of functioning costs. These costs varyconsiderably from one technology to another.Real Cost Tariff = Functioning costs + replacement and extension costs = 1.25 x functioning costs per monthNumber of householdsNumber of households30