Abstract: An interconnected and/or interconnectable frame structure supports a flexible web for use as a barrier surface in a temporary dam spanning across a waterway. The support frame includes a plurality of elongate members which are tilted away from a vertical plane in alternating senses or directions along the spanning direction of the barrier (e.g. transverse to the water flow). The thus resulting zig-zag or sawtooth elongated members are interconnected at their ends to mutually oppose further tilting movements and thus stabilize the frame and barrier structure. Pairs of the elongate members may be hinged (preferably at their lower ends) to facilitate storage and/or erection of pairs the elongate frame members from a flat storage position to an open V-shaped erected position.