Extending the scope of standard specifications for open channel flow gauging structures

The performance data given in existing flow measurement standards for open channel flow gauging structures are qualified by strict limitations which are imposed because the original supporting research did not anticipate the more extensive range of conditions used today by the water industry and the civil engineering profession. Information available in flow measurement standards was summarised and the key experimental limitations were highlighted in the Interim Report, SR 532, December 1998. Following the market survey and review, the experimental work commenced in January 1999 and was designed to cover three of the more important issues identified in SR 532, namely: to extend the range of permissible flow conditions in terms of head to weir height ratios h/P. To evaluate the performance characteristics of compound weirs without divide piers. To extend the availability of drowned flow performance data. This final report covers all three of these issues. The Department of the Environment, Transport and the Regions (DETR) partly funded this research project to extend the range of conditions in which a stage-discharge relationship for a particular structure can be predicted, thereby permitting the extension of the scope of certain flow measurement Standards. Additional financial contributions came from HR Wallingford, the Environment Agency, the Scottish Environment Protection Agency and Yorkshire Water plc