1Figure 1. Field installation of rectangular weir. HOW GOOD IS YOUR WATER MEASUREMENT?

Accurate water measurement is essential to maintaining equity of water delivery within an irrigation company or water districts. Good management of our scarce water resource is dependent upon quantifying supplies and uses with accurate measurement techniques. State water rights adjudication and management procedures often require installation of water measurement devices and keeping records of flows. Open channel (canals, rivers or streams, and ditches) devices are the most common form of water measurement in the western U.S., although often flows in closed conduits (pipelines) must be measured. Regular maintenance is an essential and often critical need to ensure continued accurate measurement. OPEN CHANNEL The most common open channel irrigation water measurement devices are sharp crested weirs and Parshall flumes. Submerged orifices and ramp flumes are also used