Sink Holes

Symptoms: Sinkholes upland of the wall, visible back-fill mounds in the water near
seawall joints (most visible at low tide)

Cause: Age, settling, structural failure, insufficient berm at the slab toe of the wall.
Slab separation allowing backfill to migrate through openings into the water.
Frequently occur after heavy rains.

Remedies: Replenish or add rock to the French Drains if fill loss is excessive.
Installation of a French Drain may be appropriate if not already present. Maintain
water passage through weep holes by cleaning or add supplemental drainage. Add
filter fabric to vertical slab joints. If berm is lacking at the slab bottoms, may require
replenishment.