How long and wide is your ww?  Here 8 x 113 straw mats run about $32 per roll and a 1000 staples are about $50.  Of course these are jobs that we are also helping to pay for.

I've never done sections like you propose so I don't know how well they would work?  But, if you do try it, make darn sure you staple the upper side heavily (1 staple per foot).  You don't want the water getting under the matting.  Hey, it is worth trying!!