Stormwater Got Inside: What's Salvageable After a Flood and What Isn't

Under the IICRC S500 standard, stormwater and rising surface water are classified as Category 3 — 'black water.' It can carry sewage, agricultural and road runoff, chemicals, bacteria, and whatever it picked up on the way in. Anything it soaked into is now a contamination question, not just a wetness question.

That reframes the whole cleanup. You are not asking 'will this dry?' You are asking 'can this be cleaned and disinfected to a safe standard, or does the material trap contamination for good?' Porous items usually fail that test; hard, non-porous ones usually pass it.

Porous and absorbent materials that soaked up Category 3 water cannot be reliably disinfected and should be discarded. Do not try to save these:

Hard, non-porous materials can typically be cleaned, disinfected, and kept, provided they are handled promptly and dried out. Good candidates:

Some items live in the gray zone, where the decision is about value and risk rather than material. Electronics that got wet should be considered a loss for safety reasons unless a professional can verify them — do not power anything on until it is checked. Irreplaceable items like photos, documents, and heirlooms are worth attempting to save even when the odds are long; a specialist can sometimes freeze-dry or restore paper and photographs that would otherwise be lost.

When you are unsure, lean toward safety with anything porous that touches skin, food, or a child, and lean toward restoration only for items whose value justifies specialized cleaning. There is no shame in throwing out a soaked couch; there is real risk in keeping it.

Before anything goes to the curb, photograph it. Insurers reimburse what you can prove, and a soaked sofa hauled away before it was documented is a claim you may not recover. Take wide shots of each room and close-ups of individual items, and keep a written inventory as you go. Our guide to documenting water damage for a claim walks through exactly what adjusters look for.

One caution specific to flooding: standard homeowners policies usually exclude rising surface water, so storm flooding is often covered only under a separate flood policy. Document either way — it costs nothing and protects you if coverage applies.

The Port Chicago Highway area of Concord sits on the lower, flatter ground in the north of the city, closer to the creeks and the Suisun Bay drainage. When a heavy atmospheric river stalls over the East Bay, water in these neighborhoods has fewer places to go and can back up across yards and into homes fast. Speed matters here more than most places — the sooner contaminated water is extracted and porous materials are pulled, the more of the house is salvageable.

For homes on this low ground, a quick, methodical flood cleanup — extract, discard the unsalvageable, disinfect the rest, and dry the structure — is what keeps a one-time flood from turning into a lasting mold and odor problem.

The mistake that undoes a lot of flood cleanups is spraying disinfectant onto a dirty surface and calling it done. Antimicrobials do not work through mud, silt, or the biofilm floodwater leaves behind — that layer shields the contamination underneath. Category 3 cleanup is always two distinct steps: physically clean the surface first, then disinfect the clean surface, and let the product sit for its full dwell time.

That dwell time is the detail people skip. Every disinfectant has a contact time on its label — often several minutes — during which the surface must stay visibly wet to actually kill pathogens. Wipe it off early and you have done little more than rearrange the germs.

The other discipline that decides the outcome is containment. Once a room is contaminated, everything that leaves it — tools, boots, debris — can track black water into clean parts of the house. We set one path in and out, bag material at the source, and clean equipment before it crosses back. Getting that right is a core part of doing storm damage cleanup safely, so the cleanup itself does not quietly spread the contamination it is meant to remove.