Field Assessment of the Flow Field in a Lateral Canal-Marsh Junction

Recently, a one-mile long bridge (OMB) was built on the Florida’s Tamiami Trail to enhance water deliveries to the Northeast Shark River Slough (NESRS) in the Everglades National Park (ENP). The OMB changed point inflows through culverts across the old Trail embankment to sheet flow through the bridge. Current guidelines for designing and assessing whether structural changes of this type conform to restoration expectations are seldom based on field studies. We present a field study aimed at evaluating of the flow distribution through the OMB based on acoustic doppler current profiler (ADCP) measurements and to identify the feasibility and potential challenges of long-term monitoring of the flow under the bridge. Our field data showed that spatial variability of the vegetation type and density in the ENP near the downstream side of the bridge and the resulting non-uniform vegetative resistance affects the distribution of the flow through the bridge. Moreover, our field data, along with analyses of other data obtained by the United States Geological Survey (USGS), showed that the flow distribution through the bridge is also affected by the presence of remnant flow paths through the natural marsh and wind speed acting upon the flow in the L-29 canal on the north side of the bridge.