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Let’s face it – we are all under pressure to save money and accomplish our jobs at a minimum of cost. In stream gauging, it is tempting to use wood (usually plywood) to make a weir from. Why not? The shape of a weir is deceptively simple - just a notch in an otherwise…

Staff ("Head" or "Level") Gauges provide a quick, visual indication of the level of water in a channel, flume, or weir. Although they should not be solely relied on when more precise level measurement devices are available, staff gauges allow operators to quickly gauge the…

Turning off the pumps is one of the last things that happen when a mine is closed. Slowly many of the open spaces of the mine begin to fill up with water. Rain starts to percolate thought the roof and walls and ground water, previously held at bay by the pumps begins to seep back…

Let’s not kid ourselves – landfill leachate is some nasty stuff. If it has gone into the landfill, there is the likelihood that it has concentrated in the landfill. This environment can make it exceedingly challenging for primary devices (flumes, weirs, and other meters) to…

Green roofs have grown in popularity in the US in the past decade. Popularized in Germany begining in the 1960's, green roofs have shown to provide benefits to the building owners and society as a whole. From a municipal standpoint, green roofs offer a number of advantages,…

In situations where flow rates are expected to vary widely, the use of a compound weir may be an appropriate solution. A compound weir commonly consists of two stages, a rectangular notch with a 90º V-notch cut into the center of the crest, but it does not exclusively have…

Weirs are best used to measure flows that contain only small amounts of suspended solids. Unfortunately in surface water applications, the amount of solids present in the flow stream cannot be controlled. Unlike flumes, which tend to be self-cleaning, weirs require regular…

The majority of errors in open channel flow measurement result from designers, installers, or operators - not from the equipment itself.  These errors result from a vareity of sources - from a lack to training to inattention to detail - and are avoidable. Avoidable flow…

In talking with customers about weirs, we run into two common misconceptions. The first misconception is that weirs can read down to zero – that there is no minimum head. The second is that weirs are more accurate at these flows than flumes. Unfortunately, both assumptions are…

A Packaged Metering Manhole (PMM) is a fiberglass manhole into which a primary device has been integrated. In addition to the above, Packaged Metering Manholes allow the integration of primary devices larger than would otherwise be able to be easily accommodated in concrete…

Portable weir plates are a good way to stretch your research dollars. Instead of the traditional approach of having a weir plate custom fabricated for each installation, Openchannelflow has simplified the process by developing a standard weir carrier with four interchangeable…

Stilling wells are chambers isolated from, but connected to, the main flow of water in a flume, weir, or channel. Isolating the stilling well from the main flow via a small connector dampens or quiets the body of water in stilling well, while still allowing it follow the steady…