backwater(a stretch of river not in the main stream); backward water; oxbow; pool; slack water; slough(на реке; further comment and example by ART Vancouver: в контексте узкого водного пространства, отходящего в сторону от основного водоёма (в данном случае реки) • In those days, a large slough cut through Ambleside and ran between Capilano River and 14th Street, and boats moored on the north side of Marine Drive. In the winter, residents skated on the frozen slough. In the summer they fished for cod, and shot pigeons and ducks on the surrounding marsh. / Eve Lazarus, nsnews.com); stank; dead-water(Anglophile); creek; cutoff; inlet
pool(A small, natural body of standing water, usually fresh; e.g. a stagnant body of water in a marsh, or a still body of water within a cave; Природный водоем со стоячей, обычно пресной водой; напр., водоем на болотистой местности или водоем внутри пещеры)