ABSTRACT
Parallel ridges and furrows in the bottom of a recharge basin facilitate maintenance of the basin using the naturally occurring forces of gravity, fluid currents, wave action and rain. The ridges can be formed from material taken from the furrows and shaped to facilitate sediment migration from the ridges into the furrows. While submerged, sediment settles on the ridges and furrows. The sediment on the submerged ridges tends to migrate toward and into the furrows. Where the sediment loading is significant, the basin can be routinely dewatered allowing wind driven or induced wave action against the sides of the ridges to wash the sediments from the ridges into the furrows, thereby maintaining the permeability of the ridges. The furrows can be allowed to become impermeable to prevent non-soluble contaminant migration. This process can be used in wastewater basins to support facultative microbes and thereby reduce nitrates.
