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Under free-flow conditions, short-throated flumes control flow in a region of the flume that produces curvilinear flow. As such, there is only one point of measurement at which the level-to-flow relationship holds. This primary point of measurement, Ha, occurs in the converging…

When the H flume was developed, analysis of the stage-to-discharge data showed that the flows could be characterized by three different equations: low flow, transitional flow, and main flow. Using those equations, though, was difficult in the field – and flow tables were…

While we often thing we seen it all, we are continually amazed by users. YouTube user Sidney Seckler has posted a video showing an unusual use for a Parshall flume: Chemical Mixing! Alum is added (as a coagulant) to the flow upstream of the flume. The flow is then accelerated…

Flumes are a common way to measuring water rights / irrigations flows on farms and ranches.

If you divert, store, or use water from a surface source or you divert water from a subsurface stream in a known and defined channel, California SB 88 requires that you report your diversion and use to the State Water Board, Division of Water Rights. This reporting is required…

With the adoption of SB 88 by the California State Water Board all smaller water users are now required to monitor and report the usage. This can be daunting. But take hope…all is not lost! At the center of any compliance program is the flow meter. For non-pumped sources, a…

On January 19, 2016 the California State Water Board adopted an SB-88: Emergency Regulation for Measuring and Reporting Water Diversions. The key provisions of the regulation call for all water rights holders to report their diversion and use of water annually. As the size of…

The traditional use for a staff gauge is to provide a visual way of determining the water level in some body of water (lake, river, flume, weir, etc.). Depending on the type of gauge, the level gradations can be anything desired - feet, meters, inches, yards, etc.

One of the most common questions that we receive is how much straight channel is required upstream of a Parshall flume. The answer is quite simple: Approach lengths shorter than the above may result in the velocity profile entering the flume not being uniform or there may be…

There are several components to measurement errors when using Staff (Level) Gauges to determine flow depth in a flume or weir. In general, staff gauge reading errors can be attributed to:

Previous studies into submerged flow and Parshall Flumes (Parshall, 1928 and Skogerboe, et al, 1967) lead to the development of submergence ratios (where flow transitions from free to submerged flow) and a corrected discharge equation. These ratios and corrected discharge…

For those unused to measuring seepage from embankment dams knowing when to measure can sometimes be challenging. In its Embankment Dam Instrumentation Manual, the Bureau of Reclamation lays out how frequently inspections should be made. Note that the table below indicates only…