Hydro Hydraulics - a disappearing art?

Over the past decade, there have been several instances where the performance of new hydro developments has been compromised by unsatisfactory operation of some component associated with the hydraulic design of the facility. This paper will outline the types of deficiencies encountered, and suggest some remedies. The incidents include - gravel entrainment at intakes; "burping" intakes; design of surge tanks; high head penstock friction; design of relief valves; turbine runner blade-wicket gate interaction; turbine draft tube rope-pipeline interaction; isolated system operation and draft tube water column rupture. Unfortunately, the author is unable to name the projects, nor provide more adequate details which could facilitate identification of the project. Owners do not appreciate information on "incidents" being divulged, and the author has signed confidentiality agreements on most of the facilities being discussed. Hence, the "incidents" have to be taken as anecdotal, but the author can vouch for their authenticity.