222893e

ECONOMIC DEVELOPMENT AND WATERA tailored integrated urban water framework for cities in sub-Saharan AfricaGroundwaterSurface waterRainwaterEvapotranspirationLeakageRainwater harvestingWatersupply Roof SurfacePublic tabConventional HHconnectionYard tabStormwatercollectionWastewaterrecycleToiletGreywaterreuseKitchenlaundry andbathroomCascadingIrrigationRunoffstoragePit latrineSeptictanksCrosscontaminationSewerInfiltrationExfiltrationOverflowInflowGroundwaterRecharge/infiltrationSubsurface flowReceiving waterSource: Vairavamoorthy et al, 2012A water framework for African citiesIUWM contextualizes the water sources, water supply, wastewaterand stormwater within an integrated urban water framework inorder to understand the dynamic interactions between the variouscomponents of the urban water system. Unfortunately, most existingintegrated frameworks, such as Urban Volume and Quality,Aquacycle or CityWaterBalance, are designed for the conditions ofcities in developed countries, neglecting the specific challenges ofcities in sub-Saharan Africa. Hence there is a need for an urban waterframework specifically designed for the cities in sub-Saharan Africa. 3An integrated framework designed for African cities has toconsider a number of water and sanitation practices characteristicof African cities. Water consumption conditions include the hugedisparity of water consumption, ranging from 40 to 255 litres perperson per day, depending on the type of service provision and thesocioeconomic status of the household. In addition tothese household consumption patterns, an integratedframework must capture the consumption from yardtaps, private wells, water kiosks and private watervendors. It must also account for a variety of differenton-site and off-site sanitation options such as pitlatrines, septic tanks and the (often missing) wastewatertreatment. The major impact poor sanitationhas on the pollution of potential water sources mustalso be accounted for. In most African cities adequatewater treatment is provided at the treatment plant, butthe potable water is contaminated in the distributionsystem. Intermittent supplies and low pressures encouragestagnancy and the entry of contaminants whichdeteriorate the microbiological water quality, resulting[ 280 ]