Economic Performance of Surface and Subsurface Drainage

Abstract

Expansion of the agricultural land base in Canada has conventionally been achieved by land clearing, often in areas with limited agroclimatic qualities more suited to wildlife habitat. Alternatively, land may be improved under favorable agroclimatic conditions. Apedaile and Rapp (1983) estimate that in east central Alberta there are approximately two million additional acres of better quality land limited mainly by excess moisture. Nevertheless, drainage in this area has been slow to take place. The research reported here assessed the economic worthiness of surface and subsurface drainage systems already undertaken in this part of Alberta in recent years. An analysis of thirty drainage projects on fifteen matched pairs of farms was undertaken. Considering all farm costs, cash benefits, taxes, and a 5 percent opportunity cost of capital, fourteen of the fifteen surface drainage projects and eleven of the fifteen subsurface projects were found to be viable. The results apply to the period 1972–84.Conclusions applying to land owners are that surface drainage is about twice as profitable as subsurface drainage where both designs are possible. Subsurface drainage is very sensitive to reductions in the benefits stream such as those arising from low prices, poor performance of the drainage design, poor management and heavy rains. Conclusions applying to government are 4hat capital assistance grants are not justified for surface projects and wouldn’t promote subsurface over surface drainage. Price stabilization and insurance would constitute an important element in any public attempt to promote subsurface drainage.