Abstract: A barrier to be installed on a ground surface includes a tranversely stiff folded longitudinal sheet folded downward about a longitudinal axis to form an apex. The longitudinal edges of the sheet are seated in furrows in the ground surface and secured by bolts to retain the barrier in place. The sheet has a chosen permeability selected according to its intended application. In one embodiment, the barrier may also be longitudinally stiff and include a raised lip for preventing water splashing over the barrier from eroding soil on the downstream side of the barrier. There is also described an apparatus for installing such a longitudinal sheet when the sheet is made of flexible material. The method of installing the barrier includes forming two furrows in the ground, shaping the longitudinal sheet so that it is folded about a longitudinal axis, placing longitudinal edges of the sheet in the furrows and closing the furrows.