An application of trend analysis to model domestic water consumption patterns for selected residential areas of Nairobi

Abstract

The City residents rely on the Nairobi City Commission for the provision of essential services of which water supply is very important. Provision of such an urban service is very challenging especially with the current population growth rate. Continued provision of water is only possible if adequate revenue is generated from water sales to cover capital, operation and maintenance costs. Collection of revenue from water sales has been a perpetual problem to the Nairobi City Commission. The major problem in this case is attributable to the delay in reading the water meters, an exercise that has had to be done before billing the consumers. The result has been the delay in billing the consumers promptly and therefore lack of proper enforcememnt for payment. It has been suggested in the past that the meter reading frequency should be reduced in the case of some domestic water consumers but bill them monthly from consumption estimates. It was the aim of the study therefore to establish whether the past average household water consum~tion followed a predictable pattern which could form the basis of billing the consumers in the same residential areas. It was found from the study that the average - vii - water consumption followed a predictable pattern which could form a base of billing consumers in those residential areas where the monthly water consumption does not vary much between households. These residential areas are populous and a lot of time is spent in reading the water meters. Monthly water billing with suitable meter reading intervals would be advantageous to the Nairobi City Commission in very many aspects of which the improvement in revenue receipts is a major one.