O Departamento de Estado tem isto a dizer na sua FAQ :
My passport has been damaged. Can I continue to use this passport?
If your passport has been significantly damaged, especially the book cover or the page displaying your personal data and photo, you will need to apply for a new passport. Conditions that may constitute damage requiring you to replace your passport include water damage, a significant tear, unofficial markings on the data page, missing visa pages (torn out), a hole punch, or other injuries.
Normal wear of a U.S. passport is expected and likely does not constitute "damage." For instance normal wear includes the bend of a passport after being carried in your back pocket or fanning of the visa pages after extensive opening and closing.
If you need to replace your damaged passport, you will need to submit the following in person (See Where to Apply):
- The damaged passport;
- A signed statement explaining the damaged or mutilated condition of your passport book and/or card;
- Form DS-11; and
- All documents required by Form DS-11, including citizenship documentation (i.e., birth certificate).
Qualquer dano causado pela água na página de dados pessoais parece ser classificado como dano.
Observe que isso exige que você compareça pessoalmente em uma agência dos correios ou em outro serviço de aceitação de passaporte, enquanto renovações regulares podem ser feitas pelo correio. Além disso, não há muita diferença.