Ground-Water Movement Controlled through Spreading

Over a period of years the Los Angeles County Flood Control District in California, under the writer's direction, has been engaged in water conservation by the diversion of clear stream flow to off-channel areas, causing the water to percolate into the soil from shallow basins and thereby adding it to the groundwater supply. This operation is known as spreading, and the areas upon which it is performed are called spreading grounds.

In the course of spreading a mound will be forr.ned above the initial groundwater table. The mound will be two dimensional or three dimensional, depending on the shape of the spreading ground. The recharge of ground water through wells is a special, three-dimensional case. The control of sea water intrusion into ground-water basins is of particular significance. The configuration of the mound, its limiting magnitude, its effective, temporary water retention both as to volume and time, its flow net for potential flow, and the drainage of the water stored in the mound are analyzed in this paper. Finally, the theoretical results are compared with results derived from model tests on two-dimensional flow.