infant stream

An infant stream is a small, gathering watercourse at the very upper reaches of a watershed. Such a stream has only begun its erosive mission of redistributing the materials of the land downhill. Infant streams are not generally protected by buffers or setbacks from logging activity, as higher-order streams downstream may be. In heavy rains, the flow in embryonic rivulets grows from a trickle to a wash. When the slopes that give rise to infant streams are denuded by clear-cutting, steep soils become saturated. Without well-established roots to hold them, entire sheets of sediments surrounding the network of infant streams may slide over the underlying bedrock, taking with them whole headwalls of the upper watershed. Such headwall failures contribute greatly to the siltation of salmon spawning grounds downstream. For this reason, and as cradles of the watersheds, infant streams deserve the same protection given mature watercourses in the lowlands.

Robert Michael Pyle