filling gaps for a water pour

[deemery]

I've just laid down a -level- plywood subbase for the creek.  But in so doing, I've created gaps between that plywood and the existing scenery.


How should I fill those gaps, given I want to pour "water" (Envirotex or Magic Water).  I was thinking masking tape, then plaster wrap, and finish with a coat of Sculptamold to cover the plywood and fill in up to the existing rock work.  

Thoughts/Suggestions?

dave

[deemery]

I had forgotten how I set up the bridge abutments.  The wood is slightly skewed compared to the stone bridge's abutment, but that's easy to fill (no structural concerns there.)


The back abutments (wood pony truss is the actual bridge here) will need more work.


dave