Hmm... you'll probably be best off making a new material for the mesh then.
Copy and paste the .material file (maybe also the images and other files and rename them) for the waterfall, paste this in:
material NAMETOWHATYOUWANTMat
{
technique
{
pass
{
lighting off
cull_hardware none
cull_software none
scene_blend alpha_blend
depth_write off
texture_unit
{
texture waterfall1.png
scroll_anim 0 1
}
texture_unit
{
texture waterfallMask1.png
scroll_anim 0 0.7
colour_op modulate
}
}
}
}
Change the name and go File >> Save.
Then go into Feralheart >> Tools >> Object Maker. Load the waterfall from the list (if saved) and in the 'Material' box type in the new name you gave it and hopefully look like as it should.
If this fails then I'm sorry but I have no other ideas on how to solve the issue :\
Good luck!