There is a small stream on my property here in Hawaii. I want to partially dam it and create a small pond on the down side of the dam so my ducks have some place to swim.
There are some large rocks in the stream, but not enough for what I want to do. Will the bags harden and become “rocks”? I don’t plan on opening the bags. I just want to place them in the stream, paper bag and all.
Should I use mortar, cement, concrete mix or something else?