Wetlands provide a variety of challenges to measuring flow.
Therefore, many important wetlands remain ungaged, and data on flow parameters for many wetlands are lacking. Developments in measurement techniques and instrumentation are needed in order to be able to gage some wetlands flow. Taylor Slough, a 158-square mile freshwater wetland, is situated along the northeastern boundary of ENP, and its boundaries extend outside the park's boundaries. Velocity measurements are currently made at each outlet, when detectable flows occur, with a Marsh-McBirney 201 flowmeter and a sliding rod. This last point is important because, in general the upstream section does not always control the flow through the culvert, especially when the culvert is flat in gradient.