Downstream of Colroy the river has been intensively built on. A part of its waters were diverted with barrages to feed hydraulic installations or "mères-royes", a local name for the main fittings used to irrigate humid grassland. More tenuous constructions aided log floating. The Fave is a substantial river considering the relative smallness of its watershed. The mean interannual flow rate or discharge at its confluence with the Meurthe is for a watershed of . The runoff curve number in the watershed is , which is high, almost twice that of the average of France with all watersheds included, and also larger than that of the French Moselle basin by a wide margin. In fact the Moselle's runoff at Hauconcourt, near where it exits France, rises to only . The specific flow rate of the Fave comes out at 18.59 litres per second per square kilometre of watershed. Fish species found in the river include trout, perch, carp, roach. Also present are water scorpions, snails, caddisfly larvae, fish fry, red-eared sliders, rare snakes, crayfish, leeches and dragonfly. Plants include bamboo species and aquatic equisetopsida.