Extended Sidewalls for Flumes

There are times when the standard sidewall height on a flume just won’t do. Sometimes the channel is taller than the flume and there is a need or desire to match the elevations. Other times a site needs additional flow capacity but there isn’t room for a larger flume. And sometimes a flume will be operating near the top of its range and there’s uncertainty if it will overflow at peak discharge rates. For these reasons and others, Openchannelflow offers extended sidewalls for some of our flume types.

fiberglass 3-inch Parshall flumes with extended sidewalls

Extended height sidewalls are most common on flumes with straight, vertical sidewalls: Parshall, Montana, and Cutthroat.

While possible, it is highly unusual to see sidewall extensions for Palmer Bowlus flumes.

Finally, extended sidewalls are not available on HS / H / HL, Trapezoidal, and RBC flumes to their sidewall geometry.

two 3-inch Parshall flumes with different sidewall heights

Keep in mind that flumes are rates for specific maximum heads - Cutthroat and Palmer Bowlus flumes in particular. As a result, the flow readings of flumes with extended sidewalls may not be as accurate as those in normal flow / head range for the flume.