Washed ¾" or larger stone with no fines drains fastest — water drops straight through the voids between pieces. Angular Gray Granite ¾" is the workhorse for French drains and soggy side yards; smooth Riverbed 1.5" does the same work in dry creek beds where the stone shows. What you don't want for drainage is a base blend — Dense Pack and stone dust carry fines on purpose so they compact and shed water, the opposite job. The deeper the voids, the faster water moves — which is why washed stone backfills every good French drain.
Wet-yard picks
| French drains, curtain drains | Gray Granite ¾" |
| Dry creek beds, swales | Riverbed 1.5" |
| Skip for drainage | Dense-graded base blends |
Compare Gray Granite ¾" and Riverbed 1.5", and size the trench or bed with the material calculator.
