Abstract: A roll-up fold-up sluice apparatus for use in separating sediment by water flow. The apparatus includes an elongate flexible mat having formed, in a central portion therein, a plurality of longitudinally spaced riffles which extend laterally with respect to the mat's long axis, and which define associated ridges and channels on the mat's upper and lower sides, respectively. The riffles are longitudinally spaced by increasing increments progressing in one longitudinal direction in the mat and are sized and shaped to accommodate a regular ridge-to-channel nesting when the mat is rolled up in that direction. A pair of flaps joined to opposite sides of the mat's central portion can be folded between folded-up positions to form the sides for the apparatus, and folded-down positions to enable rolling up.