It has been suggested that reconnection of the lower and upper portions of the Cache River will have ecological benefits. To assess potential responses and guide reconnection efforts, we have developed models predicting the ecological responses of potential increases in flow in the lower Cache River. Preliminary data suggest that duckweed cover, which is associated with lack of flow, is an important factor governing oxygen availability in the stream. We predict that small increases in discharge will reduce duckweed cover and result in exponential increases in dissolved oxygen. We also hypothesize that increases in discharge will alter macroinvertebrate communities. In particular, increased flow will shift macroinvertebrate community composition from dominance by collector-gatherers to filter-feeders such as hydropsychid caddisflies and black flies. Our model also suggests that macroinvertebrate production on snag habitats may increase up to 10% due to the increased contribution of filter-feeders. Collectively, our analyses suggest that reconnection may have tangible, positive impacts on physical and biological components of the lower Cache River.