Technical Abstract: Agriculture=s share of available water is likely to decrease in the future because of the competition for water supplies, particularly in the arid west where large irrigation projects are common. Agricultural water purveyors are being pressed by other water users to improve water measurement, control, and accounting, while their water users are demanding more flexible water deliveries so they can compete in the marketplace and implement water conservation measures on farm. Operation of irrigation-water delivery systems can be improved by providing canal operators with better tools for measuring flow rates. Radial gates are commonly used to control and measure flow rates within irrigation canals. Unfortunately, calibration of these gates has been problematic, particularly when the downstream water level is high (that is, the gate is submerged on the downstream side). A new procedure has been developed to provide reliable calibrations for radial gates regardless of flow conditions. This paper provides preliminary results of new laboratory studies to verify the procedure for a wider range of conditions. These results should be of use to irrigation districts, consultants, and the U.S. Bureau of Reclamation. Ultimately better management of irrigation water supplies will conserve water and benefit the environment.