Valor econômico da água no Estado do Ceará: uma aplicação da teoria de características de bens

Abstract

This study aimed to determine the economic value of underground water originating from wells in small rural communities in the state of Ceará, considering the characteristics of salinity. Water, as natural resource, processes economic value recognized by Law 9433 of National Hydric Resources, passed in january 1997. The analysis units used 1n this study were the wells located in sample communities in the countryside, coastal and mountainous regions of Ceará. 143 wells ffom 133 communities were used in the countryside, 47 wells in 36 communities along the coast, and 57 wells in 46 communities in the mountains. The data upon which the study was based originates from a re-census of underground water supply sources in the state of Ceará, prepared by the CPRM (Mineral Resources Research Company). The analytical model used was CGCM (Consumer Goods Characteristics Models), whose basic hypothesis 1s that consumers demand goods based on yhe utility they provide, which in tum depends on the characteristics the goods possess. The strutuctural equations established to reflect the economic value of water were estimated by the method of minimal squares in two stages (2SLS). The results obtained showed that in the countryside, the economic value of water varies between R$ 0.08/m'? and R$ 3.35/m', while on the coast this value is between R$ 0.14/m? and R$ 1.76/mº, and in the mountains it oscilates between R$ 0.05/m? and R$ 2.20/m?. The study also verified that the salinity inversely effects the economic value of water. Tha values obtained may be used as the minimum fee charged, as the populations of the communities studied now pay the respective prices for quality water. They may, therefore, be willing to pay at least the same value for higher quality water.