A NASH symposium was held at the CWRA conference in Hamilton Ontario on June 3, 2014.

Andre Bouchard presented on 'Modernizing operations at the Water Survey of Canada: From field technologies to data production" starting from a review of the business of the Water Survey and a review of conventional work practices developed during the 20th Century. I enjoyed the quote he gave from P. M. Sauder in 1909 " In organizing the Hydrographic Surveys, it was realized with the funds available, it would be impossible to make complete investigations of the whole water supply". How little some things have changed.

Acoustic technologies are driving much of the change in work practices in the the field. Demand for real-time data is driving much of the change in work practices for communication and quality control of the data.the need to introduce more advanced modeling capability is shaping future work practices.

Jeff Woodward presented a report from the working group on Discharge measurements under ice on "Ice Measurements and hydro-acoustics". Jeff provided the key differences between using a floating platform for open water with using the ice as a platform for winter measurements. He then walked through the development of hardware and software to address these differences and the role that the field campaigns organized by the river ice working group has had in guiding these advancements. New standard operating procedures were developed in parallel to the development of the technological solutions. The new standards have been published that will help hydrographers optimize their time spent in the field by ensuring the results are defensible if standards are followed. The focus of the working group field campaigns will change from primarily supporting the development of hardware, software and effective work practices to being primarily focused on training. There is also an opportunity to use thes field campaign to develop methods for the quantification of measurement uncertainty.

I presented a report on 'Building reliable rating curves". If I had a chance to do it over I would not go into so much technical detail and simply focus on the higher level concepts. The best practices for rating curve development include: BP1 have a plan that covers the entire data production cycle, is location specific and adaptive; BP2 Understand the science to be able to relate implicit assumptions to observable phenomena; BP3 Systematically investigate the hydraulic and hydrologic assumptions made to either affirm the model or to inform how the monitoring plan needs to be revised; BP4 Control the variance by adapting the curve to fit explained variance such as changing hydraulic factors and also by altering the monitoring plan to better identify and constrain sources of uncertainty. BP5 Qualify the results with inter-comparable categorization of confidence with which the data can be interpreted.

Dave Hutchinson closed out the symposium with a presentation "Revisiting the Harrison River stage-fall relation". The Harrison River gauge needs a stage-fall relation because of backwater effects from a downstream confluence with the Fraser River. The original model has been in use since the mid-1970s but recent modeling of the reach using Mike 11 has called the validity of the calibration into question. A new stage-fall calibration was fit by non-linear regression using the R scripting language.Comparison against the old model shows systematic deviation in the range from 250 to 700 m3/s and the new model generally shows more flow than the old model with differences up to 10%. The next steps are to evaluate the stability of the new model; determine if bias in old model is due to technician error; conduct analysis of mean daily flows with respect to data revision criteria and finally to integrate the model within the hydrometric workstation (AQUARIUS).