ABSTRACT A new style of portable flow-measuring flume has been designed for furrows and unlined channels. These flumes are relatively easy to install and operate. Sensitivity to leveling has been decreased by placing the stilling well near the flume throat. They are long-throated flumes and require very little head loss for satisfactory operation. They are simple to construct since they consist of a short trapezoidal section with a contraction inserted in the flume bottom. Rating tables are provided for several standard sizes with capacities ranging from 1.5 to 50 L/s (0.05 to 1.8 ftVs).