Right-Hand Chute Little River drains an Army Corps of Engineers floodway that extends roughly 20 miles from Big Lake near Manila, Arkansas to the Marked Tree Floodway (St. Francis River). Approximately 15 miles downstream from Big Lake, at Rivervale, Arkansas, the floodway constricts and there is an inverted siphon that crosses the river at right angles to the direction of flow. For all but the highest flow rates, the siphon functions as a broad crested weir and thereby controls flow rates and upstream river stages. The Corps of Engineers maintains a stream gauging station at this location. Below Rivervale, the floodway widens again to about 0.6 miles or more. In an effort to protect their lands from flooding, farmers downstream from Rivervale built a dike across the west part of the flood plain to connect to a spoil bank that runs parallel to the river more or less continuously to the Marked Tree Floodway downstream. Farmers upstream from Rivervale alleged that damming the floodplain increased depth and duration of flooding above Rivervale.

WILSON HYDRO was retained to determine the effects of damming the right overbank area of Right-Hand Chute Little River downstream from Rivervale, Arkansas on depth and duration of flooding upstream.

Analysis of the stage-discharge rating was inconclusive, but the water-surface profile analysis showed that damming the right-bank floodplain would substantially reduce the threshold flow rate at which weir submergence at Rivervale occurs. Therefore, damming the floodplain downstream from Rivervale increases the upstream flood hazard.