Water in two Height levels

I have a dam in my scene , so I have Water in 2 Height Levels (behind the body of the dam and- a waterfall and- downwards) is it possible to have hydrax water in 2 heights
-I tested 2 hydrax instances , but there where too many exceptions after runnig
-I couldn't also attach two modules to a hydrax object

Thanks

finally I handled it.
I used ogre ocean for downwards and hydrax as the lake behind the dam.But now I need to have hydrax in a complex shape.is it possible to have hydrax water in a ploygonal shape ?

it is a dam and water in the back of the dam is U shaped