Drive through any older Carroll County neighborhood and you'll spot them: retaining walls bowing out at the middle, a top course tilted toward the yard, mortar joints cracked open. Almost none of those walls failed because the block or stone was bad. They failed because water got behind them and had nowhere to go.
Our soil here is heavy clay. It holds water, it expands when it freezes, and it pushes. A wall built straight on dirt, with dirt shoveled back behind it, is fighting that pressure from day one. The first few winters loosen it; the next few tip it.
A wall built to last starts below grade with a trench and a compacted crushed-stone footing, so the first course sits level and stays level. Behind the wall goes clean drainage stone, not soil, with a perforated pipe at the base that daylights somewhere downhill. On taller walls, layers of geogrid tie the block back into the slope so the whole hill, not just the block, is holding the load.
None of that is visible when the wall is finished, which is why cheap walls look the same as good ones for about two years. If you're getting estimates, ask what goes behind the wall. If the answer is 'we backfill it,' keep looking. If you'd like us to look at a slope in Westminster, Eldersburg, Sykesville, or anywhere in Carroll County, walkthroughs are free.