I picked up some EnviroTex at Michaels using a 40% coupon that they provide on-line. If you have a Michaels near you it’s well worth the effort to sign up for their newsletter. Coupons are one of the reasons. Knocking 40% off the price of the EnviroTex moves it from expensive to affordable.
Here’s looking at the dam from behind. I colored in blue where the ‘water’ will go. I doubt that much of this will be seen with it on the layout but .. shrug .. will be a first time to use this EnviroTex so suppose is good practice as the creek was also to be created using the epoxy.