Hydraulic ram pumps and Sling Pumps

Finally it should be mentioned that tree planting and keeping are not primarily decoration, but satisfyan environmental demand. Botswana is very much affected by soil erosion. The Governmenttherefore directs that all support should be given to tree planting. An annual tree planting day enjoyspublic attention and nurseries are being founded in many places. Therefore, any water consumptionrestriction has a substantial effect on environmental conservation. Hence unconventional ways hadto be found to continue environmental conservation while at the same time saving as much water aspossible.Table 2: Development of water tariffs in Lobatsa1.3 Water saving and reuse of water1.3.1 Domestic water saving1.3.2 Bath or shower1.3.3 Reuse of domestic water1.3.4 ConclusionWater saving in semi-desert countries is essential and should be encouraged as much as possible.To support saving, it is first important to understand how water is wasted.By way of example, let us consider a selfhelp housing area. In Botswana this area is suppliedthrough standpipes on the side of streets, never more than 100 metres away from a house. Tenantsare supposed to build pit latrines before they are allowed to construct dwelling rooms. People fillcontainers several times a day and carry the water home. Although the supply of water is muchbetter than in villages and distances are much shorter, the water still has to be carried. One who hasto carry water to the point of use will hardly waste it, and exactly this is the experience gained. It wasobserved that people became used to collecting their washing water after use, and watering theirplants in the courtyard. As the water bills in Lobatse showed, consumption of water per standpipe inself-help housing areas, although used by 7-10 families, is lower than the consumption for one highcost house. It has been suggested that the consumption in residential houses rises with the numberof taps and other sources connected to the central supply. Unfortunately, statistics are not availablebut observations appear to confirm this. However, the conclusion from the above should not be topropose public standpipes as a solution. The general conclusion can only be that the convenience ofaccess to water raises consumption. If this is understood, we should have a close look atpossibilities of saving domestic water.1.3.1 Domestic water savingIn domestic water use the waterborne toilet system, in general, is the highest consumer of water.Moreover, the water used is not fit for reuse and goes into the sewers. Recycling of sewer water ispossible but expensive and can only be done in special ponds. It has been observed that at a schoolwith water closets (12 toilets each consuming 10 litres per flush), the consumption of these flushtoilets is higher than the consumption of 1000 pupils and their teachers for drinking, cooking one8