Storm Water on the Carpet in Dixon: Rainwater vs Floodwater

How do you tell rainwater from floodwater on a Dixon carpet?

Start with the route the water took. If it came down through the roof, a skylight or a window frame and landed on the carpet, that's rainwater intrusion. If it came across the yard, the street or a field and pushed in under a door or through a wall at ground level, treat it as floodwater.

The difference matters because the guidance is different. The EPA's flood cleanup page says that if water came from "a pipe leak or rainwater intrusion," the damage "typically presents fewer hazards and affects a smaller area than damage from hurricanes and floods." Its flood advice is written for the other kind.

These clues are rules of thumb, not a lab test. Use them to sort out what you're dealing with before anyone arrives.

What does the IICRC S500 consensus body say about storm water?

That weather alone doesn't decide it. The IICRC S500 consensus body, which writes the S500 water damage standard, issued a position statement on weather-related water, dated February 2026. It says "Top-down water ingress, wind-driven rain and water from weather related events are not automatically considered Category 3 Water."

The Category 3 definition quoted in that statement calls it "grossly contaminated" and lists examples that include "rising water from rivers or streams." It adds that Category 3 water "can carry trace levels of regulated or hazardous materials (e.g., pesticides, or toxic organic substances)."

So who decides? The restorer, after looking. The statement quotes the standard's definition of a preliminary determination as a "process performed by the restorer to establish the category of water for the purpose of establishing a scope of work." It also quotes this line: "Time and temperature can affect or retard the amplification of contaminants, thereby affecting its category." In plain terms, the category isn't fixed the moment the water lands, which is one more reason not to leave a wet carpet sitting.

Why does the difference matter in Dixon?

Because Dixon is ringed by farmland and runs its own drainage system. The City of Dixon's stormwater page says the storm drains are "a separate piping system independent of the sanitary sewer collection system," and that the system "is intended to collect only rainwater runoff." The runoff is held in detention ponds and then sent into the Dixon Resource Conservation District ditch system south of the city limits, which drains into Hass Slough.

That tells you about the pipes, not about what the water touched on the way to your door. The city's Natural Environment Element background report, a final draft dated September 2022, says "Most of Dixon, however, is not within a flood hazard zone." It names some residential areas "at the south end of the city near SR-113 and near Northwest Park" as subject to flood hazards, and says the agricultural land around the city falls within the 100-year or 500-year floodplain.

The same 2022 report said neighborhoods "with pollution from pesticides, fertilizers, and industrial facilities" in northeastern Dixon sit within a flood hazard zone, and that flooding there can cause "toxic chemicals and contaminants to spread into the water and soil." The CDC's disaster cleanup guidelines make the general version of the point: "Floodwater can contain dangerous bacteria from overflowing sewage and agricultural and industrial waste." Flood maps change, so check your own address on FEMA's Flood Map Service Center rather than relying on a 2022 report.

It can matter to your insurer too. The Solano County Water Agency's flood preparedness page says "Standard homeowner policies do not cover flooding," and the California Department of Insurance residential guide lists flood among the perils generally not covered by a homeowners policy. Policies differ, so read your own exclusions and ask your agent.

What can you save, rainwater or floodwater?

More after a roof leak that's caught early than after a flood. The table below sets the federal guidance side by side: the EPA mold course's drying advice for clean water that's caught early, and the CDC's disaster cleanup guidelines for floodwater.

For clean water that's caught early, the EPA's mold course says "To dry carpet and backing within 48 hours, remove water with a wet vacuum, pull the carpet and pad off the floor and dry them using a fan to blow air over them." It adds that "In most cases, mold will not grow if wet or damp items are dried within 24-48 hours." That guidance is for clean water, and the EPA says not to use fans until you have determined that the water is clean or sanitary. If you can't tell, the restorer's inspection described above is what settles it.

For floodwater, the CDC says to "Throw away anything that you can't clean or dry quickly," and its list includes "carpeting, carpet padding, rugs, upholstered furniture." It also says to "Remove and discard drywall and insulation that has been contaminated with sewage or floodwater." Hard items are a better bet: the EPA's flood page says "You can usually clean and dry materials that do not soak up water." Our guide to what to throw away after water damage goes item by item.

What should you do first?

Stay safe, record it, then get the drying started. In order:

1. Keep out of flooded streets. The City of Dixon's storm information page warns that "Just a few inches of water can cause you to lose control of your vehicle or cause you to fall."
2. Report flooding to the city on (707) 678-7000 during business hours or (707) 678-7080 after hours, and call 911 if a life is at risk.
3. Use the clue table near the top of this page to decide whether you're looking at rainwater from above or floodwater from outside.
4. Photograph every wet room, the ceiling or doorway where the water came in, and anything on the floor, before you move it.
5. If it's floodwater, wear the gear the EPA lists for flood cleanup: an N-95 respirator, goggles without vent holes, gloves, pants, a long-sleeved shirt and boots or work shoes.
6. Keep children and pregnant people out of floodwater cleanup, which the EPA says they shouldn't take part in.
7. If floodwater reached any part of your heating or air conditioning system, read the EPA flood page's section on HVAC systems before you switch it on to dry the house.
8. Get drying started. The CDC says to dry your home "within 24 to 48 hours if possible" after the storm or flood ends.

Before the next storm, the city's storm information page says sandbags are available at the Dixon Fire Station, 205 Ford Way, Monday to Friday from 9:00 am to 5:00 pm. The sand is self-serve at the northwest corner of A Street and Jackson Street, so bring your own shovel. The city's stormwater page adds that sand for county residents is at the end of Industrial Way. The city also lists Alert Solano, the county's emergency notification system, among its storm resources. Our rain season prep guide covers the rest of Solano and Napa.