Waterfall help- need ideas please

As I posted in a previous msg, rodents have destroyed my waterfall
eating through the liner. I am looking at possibly using a plastic
waterfall spillway (homemade or bought), but am wondering how to
conceal it with the type of waterfall and stone I have. Any suggestions
or other ideas on how I can fix this are appreciated! I hate to just
replace the liner and have it destroyed again.

This will give you an idea of my pond:

http://www.neticca.com/pond.html


Thanks