Retraction

Mr Warren Tyson near Wagga Wagga built one before me. He developed  a turbine that would not catch flotsam during floods. It was anchored in the Murrumbidgee river near Wagga. The story below is from the web site below. I dont know if Warren has a boat mill in Australia any more.
http://www.ncsmed.org.fj/index.php?option=com_content&view=article&id=62&Itemid=77
 

Tyson Turbine

The Tyson turbine project was funded by AusAID. The project aim was to install a hydro electricity generator at Naravuka village near Seaqaqa in Vanua Levu. The concept was introduced as a conduit for enterprise development through the provision of electricity to a rural based community. The inventor of the turbine Mr. Warren Tyson helped in the installation of the turbine. Project Benefits The Tyson turbine has been marketed worldwide as the world’s first environmentally friendly machine that provides the versatility of water pumping and power generation simultaneously. Its key benefits include: Cheap remote area power supply Generates up to 3 kW electricity per hour. A large village requires approximately 12 kW of power, surplus power is stored in batteries. Effective water pumping operation at 0.75m/sec water flow only Renewable energy system, highly corrosive resistance Easy installation and low maintenance