Doing it to last
Menlo Park's irrigated lots kill posts the standard Peninsula way — rot in the band at the soil line. The lasting fix: old footing out, gravel base in, concrete crowned above grade, and on lots where sprinklers can't be redirected, steel posts under the original wood panels end the problem permanently.
Next step
Push the fence at the top; photograph the base of every post that pivots. Send through the form — the count from photos is usually smaller than the fence's lean suggests.
Post replacement in full: see the service page. City rules: see the Menlo Park page.