The invention relates to a cover and sump assembly for a main drain of a pool or spa that prevents suction entrapment, and specifically, to an assembly having a frame with openings, plates with openings positioned on the frame, and a sump for collecting water and receiving the frame. The assembly reduces the velocity of water flowing there through, uniformly distributes a suction force created by water flowing into the sump, prevents a vortex of flowing water above the assembly, and provides anti-entanglement features to minimize the likelihood of an individual becoming entrapped on the assembly by a suction force produced by a pump in the pool or spa filtering system. The assembly includes a conduit defining an opening along a lower portion thereof that reduces the velocity of flowing water at the suction opening in the sump by reorienting the suction port from a vertical to a horizontal orientation.