Method of forming a subterranean water barrier and a plow for use

Abstract

A method of forming a plurality of horizontal barriers in situ at a preselected depth beneath the soil surface and in a plane substantially parallel to the soil surface so as to be coextensive with a desired area, the barriers being made of a thermoplastic material such as asphalt for example, and forming further barriers joined to the horizontal barriers and extending vertically or obliquely toward the soil surface in order to surround the above-mentioned area, thereby improving soil having a poor water retention property. The method further comprises the steps of filling up chambers in a plow moving in the soil with the barrier forming material in the liquid form, leaking the material out of the chambers through passages of a given gap, and spreading the formed film laterally uniform by an ironing portion connected with the plow near the passages so as to render the formed water barrier uniform in thickness and free from apertures.