design principle varied, multiple surface barriers increase infiltration Varied and multiple structures reduce the velocity and energy of flow. Cumulatively, many structures slow flow long enough for it to infiltrate rather than flow overland and erode surfaces. These include horizontal, above-ground, and ground-surface structures that intercept; vertical structures placed in the path of flow that cause friction, creating turbulence that slows flow; porous structures in the surface that aid in infiltration and retention; and topographic features that increase surface roughness, resulting in temporary pooling.
Related design principles: • • •
TOC
Chemical compounds can increase holding capacity. Structures capture solid elements. Local materials decrease water flow.
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