What is the least expensive retaining wall IDEA?

Hi Joanne, Here's a video that may help: https://www.youtube.com/watch?v=_4GTLt_y4oM

Good luck!

If you don't want to do it more than once use landscape blocks. They are designed to stack together and will allow for drainage. It is the lack of drainage that makes most walls fail. If you are strong and able a dry wall can last a very long time, but gathering and stacking the stones is WORK. Large treated landscape ties may work for you, but they are expensive too.

Check to see if any state county city codes come into play. With a larger water feature there may be. Get your under ground utilitys marked. You don’t want to have that beautiful water feature trashed because it was build over the sewer line the city is replacing.

Google or Pinterest gabion retaining walls. Buy some appropriate-size baskets and invite your friends and family to collect rocks for you.

Cheap as I am, I’d buy the baskets because making anything like these out of wire will destroy your hands and, ultimately, your personality. Most certainly your enthusiasm.

You don’t appear to have a huge rise, so tall baskets aren’t necessary. They will flatter your rock garden, and stay exactly where you put them. Never have to be painted, and so forth.

Use jute erosion control fabric. Since you will be adding rocks, a waterfall and pond, the jute will stop the soil from washing away and you can start planting shrubs and flowers and a stairway. All the vegetation will then keep everything in place. The fabric is relatively inexpensive and will be a more natural look with your rocks, etc. than walls. Good luck.