Drainage services demand and supply
This chapter addresses the economics of land drainage in agriculture - a subject that is the poor and neglected cousin of the economics of irrigation. Land drainage can be defined as those processes, natural and social, by which flows of water on the land, at both surface and sub-surface levels, are conducted to other locations, such as lake, river and aquifer. The outcomes of drainage activity are not necessarily confined within the boundary of a single farmholding and therefore, like wastewater collection and disposal, drainage services may be a public good (Jacobs et al. 1997: 86; Merrett 1997: 66-8). A public good can be defined as any good where the benefit derived from it by one consumer does not diminish the benefit derived by consumers in general. The standard textbook example is a country's armed forces (Sandmo 1987: 1061-7). Since no consumer privately appropriates a public good, it is often difficult and sometimes impossible to price or sell it in a free market.