The towns sheltered by the shingle spit were once important harbours, but land reclamation schemes starting in the 17th century resulted in the silting up of the river channels.
The tide gauge continued to operate where it was originally constructed until 1943 when silting up of the site reputedly interfered with its operation.
The distant dam is still functional, but silting up, which is expected to reduce its storage volume, and therefore its effectiveness at flood-prevention.