Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? How can I turn shoreline into a sand beach?

you could use quickrete instead of rock https://www.core77.com/posts/80454/...the-Bag-Stack-Like-Legos-Wet-With-a-Hose should work to help contain that sand as it meets the grass/weedline
If you don't want weeds to come through use a woven fabric goetex - similar to those used for heavy equipment to drive into construction sites. I help out on a 3 acre pond that was built 30ish years ago having 2/3 of the shoreline covered with 2 layers of woven geotex fabric, covered with gravel and <6 rock over that. never has weeds but the lawn is very well cared for