Water always wins—unless you give it a path. Behind bulkheads and seawalls in Charleston, trapped water creates hydrostatic pressure that bows walls, pops fasteners, and chews through backfill. The fix isn’t flashy, but it’s everything.
Weep holes
Strategically spaced outlets let water escape. Pair each opening with filter fabric so soil stays put and only water moves. No fabric = clogged holes and sinkholes.
Filter fabric + #57 gravel
Think of fabric as the “coffee filter” and #57 stone as the grounds—the fabric keeps fines out while the stone creates an easy water path. We wrap fabric on the soil side, then place gravel to create a free-draining zone.
French drain lines
Where grades push more water toward the wall (hello, Mount Pleasant and Hanahan backyards), a perforated drain set in #57 stone behind the wall collects and routes water to daylight or approved discharge. Coordinate with stormwater rules so you’re not crossing the line (see Blog 7).
Construction details matter
Good headers/stringers, proper tiebacks, and correct sheet embedment work hand-in-hand with drainage (see Blog 5 on wall types and Blog 10 on piles). Skip any one piece and the rest suffer.
Charleston Dock Doctors LLC designs drainage with permitting in mind—OCRM/Army Corps expect pressure-relief done right. If your waterfront wall in James Island, Awendaw, or Wadmalaw shows bowing or soil loss, call Charleston Dock Doctors LLC. We’ll rebuild the science behind the structure.
