Thanks guys, I did find the HFlume by Tracom.
My intended use is screened wastewater. One flume on a 24" DIP discharging into an orbil and one on an 18" DIP discharging into a solids contact unit. Flows ranging up to 6 MGD.
The H-Flume will take some support; however, it is still shorter and less expensive than say a parshall flume.