The first 24 hours, in order

The whole response in nine lines. Each one links to the detail further down.

  1. Settle the power from outside the space. Main breaker off only if you can reach it from a dry spot; otherwise an electrician. Nothing electrical gets touched while you are standing in water. Electricity
  2. Check for gas. A smell or a hiss means leave now and call the gas company from somewhere else. If water has reached a gas appliance or the meter, turn the gas off at the meter only if that is safe. Gas
  3. Look from the hatch, not from inside. A sewage smell, a shifted post, or being alone in the house each rules out going in. What is in the water
  4. Photograph the water at its highest, with something for scale, before anything moves. What to photograph
  5. Stop what is still coming in. Check the downspouts, the gutters and any surface water running at the house. Getting the water out
  6. Tell your insurer, even if you are not sure the loss is covered. Insurance
  7. Pump from the lowest point, then wet-vac the rest, discharging well away from the foundation. Pumping out
  8. Take out what is soaked, but keep it for the adjuster if you are claiming, or photograph it and keep a sample. What comes out
  9. Start drying at once: EPA's target is to dry water-damaged material within 24 to 48 hours. Drying

Nothing that sat in the water goes back into service until it has been checked: the electrical system by an electrician, gas equipment by a licensed HVAC technician or plumber, and a sump pump only once it is completely dry.

Before you go anywhere near it

Four checks, in this order. None of them requires going in.

1. Electricity

Crawl spaces carry wiring, junction boxes, sump pumps and sometimes a furnace. CDC's guidance for reentering a flooded home is precise about the sequence: if you can turn the main power off from a dry location, do it — even if that delays cleaning up. If reaching the main switch means standing in water, call an electrician rather than doing it yourself. And never operate a switch, tool or appliance while you are standing in water.

The same guidance applies going the other way: have an electrician check the system before power is restored, and do not put equipment or appliances back into service until they are completely dry. A sump pump that sat submerged is in that category.

2. Gas

A crawl space can carry the gas supply to a furnace or a water heater, and sometimes the appliance itself. If you smell gas or hear a hissing sound, leave the house now. FEMA's flood claims handbook adds the detail that matters: call the gas company from somewhere else, because a landline or cell phone used inside a building with a gas leak could spark an explosion.

If there is no leak but the water has reached the level of your gas meter or a gas appliance, NW Natural's guidance is to turn the gas off at the meter if you can do so safely, and to tell them you have. Afterwards, do not turn a meter back on yourself, and do not use a flooded meter or any gas equipment that sat in the water: NW Natural says submerged gas equipment must be inspected by a qualified, licensed HVAC technician or plumber before it is used again. If your gas comes from a different utility, follow its instructions instead.

3. What is in the water

CDC's list of what floodwater can contain is worth reading rather than summarising: human and livestock waste; household, medical and industrial hazardous waste; downed power lines; coal ash; other germs and contaminants; and wild or stray animals, including rodents and snakes. In a Portland crawl space the realistic ones are sewage where a line has backed up or a septic system is involved, and rodents that were already living there and are now displaced.

If you do go in, CDC's minimum is rubber boots, rubber gloves and goggles. Cuts and broken skin get covered. If there is any smell of sewage, that is a stop signal — that is not a homeowner cleanup and it is not a crawl space contractor's job either.

You may hear the phrase Category 3 water. It comes from the restoration industry's water damage standard, which grades water by how contaminated it is — Category 1 clean, Category 2 greywater, Category 3 grossly contaminated. That standard is a paid document and this site has not read it. What is public is the IICRC's own 2026 position statement, cited below, which pushes back on classifying weather-driven water by the weather: it calls for inspection and information gathering before a determination. So if a contractor assigns a category before looking, asking what they based it on is a fair question with the association behind it.

4. The structure and the space itself

A crawl space is a confined space: one way in, one way out, no ventilation to speak of, and no second person to notice if something goes wrong. Add standing water and soft ground and the ordinary hazards get worse. Look for a support post that has shifted or is standing in water, and for anything hanging that was not hanging before — a duct, a pipe, insulation that has come down. If you are alone in the house, looking from the hatch with a torch is a complete and reasonable answer.

Never run a generator, pressure washer or any petrol engine inside the house, in a basement or garage, or less than 20 feet from a window, door or vent. Carbon monoxide is a recurring cause of death during flood cleanup. If pumping needs an engine, the engine stays outside and away from openings; only the hose comes in.

Getting the water out

Once the power and gas questions are settled, removal is a sequence: stop the inflow, record it, then match the tool to the depth and have somewhere legal to send it.

  1. Stop what is still arriving. Pumping while it comes in is holding an umbrella. Worth doing to stop it getting deeper, but the useful move is outside: check whether a downspout has come apart, whether a gutter is overflowing at a corner, and whether surface water is running toward the house. Those are same-day fixes and they sometimes stop the inflow entirely.
  2. Photograph it before you pump. The water at its highest is evidence that exists only until you remove it. What to photograph takes ten minutes.
  3. Several inches or more: pump from the lowest point. A submersible utility pump in the lowest spot, discharging well away from the foundation — not against the wall you are trying to keep water out of, and not into a neighbour's lot. If the crawl space has a sump basin and the pump is dead, that is the same job.
  4. An inch or less, or the last of it: wet-vac. Slower, but it reaches what a pump leaves behind, and the last half-inch is what feeds the humidity for the following month.

Where the water goes matters as much as getting it out. Discharging at the foundation sends it straight back under the house, which is the most common way a long afternoon achieves nothing.

Drying, and why nobody can tell you how long

No public authority publishes a crawl space drying time. We looked: there is no EPA, CDC, FEMA or extension-service figure for it, and the numbers that circulate come from restoration companies describing their own jobs rather than from a method anyone can check.

The number that matters is not on a calendar, it is on a moisture meter. The restoration industry frames drying around a moisture-content target rather than a duration, and there is a well-established target to aim at: the USDA Forest Products Laboratory puts serious decay above the fiber saturation point, averaging 30% moisture content, and states that fully air-dried wood usually will not exceed 20%, which should provide a reasonable margin of safety against fungal damage. So the question to ask a contractor is not "how many days" but "what reading are you drying to, and how will you know when you have got there".

What the answer depends on is genuinely variable: how much water there was, whether the soil drains or holds, how much air moves through the space, the outdoor temperature and humidity, and whether the crawl space is vented or sealed. In a Portland December the outdoor air is often close to saturated, which is exactly when ventilation stops helping and mechanical drying starts being the only thing that works.

On timing, EPA's guidance is worth stating exactly as EPA states it, because the version repeated everywhere else has it backwards. EPA says to dry water-damaged areas and items within 24 to 48 hours to prevent mold growth, and that in most cases mold will not grow if wet materials are dried in that window. That is a target, not a countdown that has already expired. It is still the best reason to move quickly.

The drying itself runs in this order:

  1. Open up whatever is trapping water. If water got under the vapor barrier, the sheet comes up so the soil can dry, and soaked batt that is holding water against the joists comes down — what comes out and what stays is below.
  2. Move air, and dry it. Fans help. In the wet months, when the outdoor air being drawn in is close to saturated, mechanical drying is what actually removes the moisture.
  3. Measure the framing. Readings, not days: the Forest Products Laboratory's figure for air-dried wood is 20 percent moisture content or less.
  4. Only then close it back up. The same handbook says wet wood should not be enclosed until it is thoroughly dried, so new insulation and a new barrier go in over framing and soil that have measured dry — and equipment goes back into service only after the checks at the top of this page.

What comes out and what stays

The dividing line is porosity, not wetness. EPA lists fiberglass insulation among the porous materials that may have to be discarded after water damage — its stated reason is that mold infiltrates porous substances and fills the spaces in them, so removing it completely can be difficult or impossible. Hard, non-porous surfaces can generally be cleaned and dried instead.

  • Soaked batt insulation. The usual candidate for removal, and it is also the thing most likely to be holding water against the joists above it long after the floor is dry. Wet batt that has fallen is not going back up.
  • Cardboard, paper, stored fabric, anything organic. Out. A crawl space is not storage, and after a flood this is the easy decision.
  • The vapor barrier. Plastic sheeting is not porous, but water trapped under a barrier does not evaporate. If water got beneath it, the sheet has to come up to let the soil dry, and it usually gets replaced rather than relaid.
  • The framing. Stays, and gets dried and measured rather than judged by eye. Wood that has been wet for a day is in a completely different position from wood that has been damp for years.
Soaked insulation hanging out of the joist bays onto a torn black plastic sheet across a crawl space floor, with scraps of insulation and debris scattered over it
Soaked batt insulation come down from the joists onto a torn plastic ground cover. Fallen wet batt does not go back up, and water under a torn sheet cannot evaporate, so both are removal decisions, and both are photographs first if there is a claim.

Note what EPA's wording actually is: porous materials may have to be discarded, and the condition is mold growing on them rather than the material simply having been wet. Anyone telling you every wet item is automatically waste is going further than the guidance does.

If you are going to claim, removing and discarding are two different steps. FEMA's flood claims handbook says to take out wet, non-salvageable material to limit mold, but not to throw anything away before the adjuster has seen it unless it is a health hazard or local law requires it — and if something must go, to photograph it first and keep a sample for the adjuster. In a crawl space that means bagging a piece of the insulation and the barrier rather than all of it going in the dumpster.

What to photograph before you touch anything

Ten minutes here is worth more than any other ten minutes of the day, and it costs nothing. Whether or not you end up making a claim, you will want a record of the state the space was in.

  • The water at its highest, with something for scale — a tape measure, a ruler, your own boot.
  • A wide shot from the hatch, then the low corner, then wherever water appears to be entering.
  • High-water marks on the piers and stem walls once the level drops.
  • Anything you remove, before you bag it.
  • The date and time, which your phone records anyway.
  • Outside: the downspouts, the grade against the house, and any pooling in the yard.
Water pooled across the bare soil floor of a crawl space, with concrete-block piers standing in it and exposed floor joists overhead
The wide shot worth taking before anything moves: water across the whole floor, and the piers it stands against, which will carry the high-water mark once the level drops.

FEMA's claims handbook is written for NFIP flood policies, and your own policy's wording is what governs your claim, but its first steps make a reasonable checklist whoever your insurer is:

  • Give notice promptly, in writing, even if you are unsure the loss is covered or exceeds the deductible.
  • Keep what you remove until the adjuster has seen it, unless it is a health hazard or local law says otherwise. Anything that has to go gets photographed first, with a sample kept.
  • List and photograph possible structural damage you want the adjuster to see. The handbook's examples include visible cracks and sagging or uneven floors.

Keep receipts for pumps, fans, dehumidifier hire and anyone you pay. Whether any of it is recoverable turns on your policy and on what caused the water, which is a conversation to have with your carrier rather than with a contractor — and one that goes better with the photographs already taken.

When to stop and call somebody

Some of these are safety, some are simply the point at which a homeowner afternoon stops being the cheapest option:

  • The main power cannot be reached from dry ground. Electrician, before anything else.
  • Any smell of sewage, or a known backed-up line. Different trade, different equipment.
  • Water is still rising, or arriving faster than a pump moves it.
  • A support post has moved, or something structural is visibly out of place.
  • It is still wet a week later despite the water being gone — that is a drying problem, and it is the one that turns into a mold problem.
  • This has happened before. A second flood is not an emergency, it is a design fault, and it should be priced as one.

Then: why it happened

This part can wait until the space is dry, and it is the part that decides whether you do all of the above again in February.

Start by working out whether the storm was the cause or the trigger. Portland's wet season runs November to March and does produce genuinely exceptional weather — on 17 December 2025 the Oregon Department of Emergency Management activated the State Emergency Coordination Center to Level 3, Regional Response, ahead of an atmospheric river, with National Weather Service flood watches covering fourteen counties including Multnomah, Clackamas and Washington. A crawl space that took water only in that kind of event is a different problem from one that takes water in an ordinary December week, and the honest way to tell them apart is not the storm at all: it is whether there are high-water marks, staining or efflorescence on the piers and stem walls from before this one. Evidence of previous events means the entry path was already there.

Which reason changes what you buy, and the two other guides on this site split along exactly that line:

  • Water that arrives with a storm and drains away again is usually surface water reaching the foundation. Water in a crawl space after rain covers the sources and the cheap fixes, several of which are gutters and downspouts rather than contractors.
  • Water that is there through the wet season regardless of individual storms is usually the water table. Standing water in a crawl space covers what that means and why grading will not fix it.

Where the fix is construction rather than gutters, it is normally drainage with somewhere for the water to go — an interior perimeter drain at $3,825 to $6,800 in this metro, or a sump pump alone at $1,525 to $2,975 where the drain lines exist and only the pump has failed. What each scope includes is worth reading before the first quote arrives, because the widest gaps between bids are scope differences rather than price differences.

Portland Crawlspace Pros is a free matching service — it connects homeowners with independent licensed Oregon CCB and Washington L&I contractors and does not perform the work, and it does not do emergency water extraction. If what you need today is the water out, a restoration company is the call. If what you want is for this not to happen again, a free inspection before the next storm is the useful appointment, and the dry months are the easier window to do the work in.

Sources

Every safety instruction on this page is CDC's, EPA's, FEMA's or NW Natural's rather than this site's, and is quoted rather than paraphrased where the wording matters; the insurance steps are FEMA's NFIP claims handbook. Two claims common on competing pages are deliberately absent: that mold begins growing within 24 to 48 hours, which reverses what EPA actually says, and that all flood water is Category 3, which the restoration standards body itself disputes. No stream gauge reading is attributed to the December 2025 storms — the reporting available describes Johnson Creek approaching minor flood stage rather than cresting above it, and no primary gauge record was obtained.

  1. Centers for Disease Control and Prevention, Safety Guidelines: Reentering Your Flooded Home Checked

    The electrical sequence before entering a flooded space: turn the main power off only if the switch can be reached from a dry location, otherwise call an electrician; never operate a switch or a powered tool while standing in water; have an electrician check the system before power is restored. Also the rule that generators and other petrol engines never run indoors or within 20 feet of a window, door or vent.

  2. Centers for Disease Control and Prevention, Safety Guidelines: Floodwater Checked

    What floodwater can contain — CDC lists human and livestock waste, household, medical and industrial hazardous waste, downed power lines, coal ash, other germs and contaminants, and wild or stray animals — and the protective equipment for entering it: rubber boots, rubber gloves and goggles.

  3. NW Natural, Emergency preparedness at home Checked

    The gas steps in the flood guide, in the utility’s own terms: if water rises to the level of the gas meter or appliances, turn the gas off at the meter if that can be done safely and tell NW Natural; after a flood, do not turn a meter back on yourself, do not use a flooded meter or any gas equipment, and have any submerged gas equipment inspected by a qualified, licensed HVAC technician or plumber before it is used again.

    Note: NW Natural’s guidance for its own customers. A home supplied by a different gas utility should follow that utility’s instructions.

  4. Federal Emergency Management Agency, National Flood Insurance Program, National Flood Insurance Program Claims Handbook (FEMA F-687, August 2024) Checked

    The documentation steps after a flood: give the insurer prompt written notice even when unsure the loss is covered or exceeds the deductible; do not discard anything before the adjuster sees it unless it is a health hazard or local law requires it, and if something must go, photograph it first and keep a sample for the adjuster; list and photograph areas of potential structural damage, which the handbook says include sagging or uneven floors. Also its instruction to leave at once on smelling gas or hearing a hiss and to call the gas company from somewhere else, and its example that flood water seeping into a basement may be covered while water slowly permeating the walls from a natural rise in groundwater is not. And that a denial can be appealed to FEMA within 60 days of the date on the insurer’s denial letter, and that a flood policy pays to bring a building up to code only through its Increased Cost of Compliance coverage.

    Note: Written for NFIP flood policies. A homeowner policy, or a flood policy from a private insurer, has its own wording, and the carrier on the claim decides what applies.

  5. Federal Emergency Management Agency, Flood Insurance Checked

    That most homeowners insurance does not cover flood damage, and that a new NFIP policy typically has a 30-day waiting period before it takes effect, except where the coverage is required by a lender or follows a flood map change.

  6. United States Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home Checked

    Indoor humidity targets, EPA’s position on when sampling is and is not worth paying for, its position on biocides, the general health effects of damp indoor spaces, and the 24–48 hour drying window — which EPA states as a PREVENTION target ("dry water-damaged areas and items within 24-48 hours to prevent mold growth"), not as a time by which mold begins.

  7. United States Environmental Protection Agency, Mold Course, Chapter 4: General Remediation Issues Checked

    Which water-damaged materials can be dried in place and which may have to be discarded. Fiberglass insulation is named explicitly among the porous materials, and EPA’s stated reason is that mold infiltrates porous substances so completely removing it can be difficult or impossible.

    Note: EPA says porous materials "may have to be discarded" and conditions that on mold growing on them — not on the material merely being wet. Contractor copy routinely hardens this into a rule that all wet insulation must come out; the source does not say that.

  8. Institute of Inspection, Cleaning and Restoration Certification, Position Statement on Category of Water Damage and Weather-Related Events (IICRC position statement, 16 March 2026) Checked

    The three water categories a restoration contractor will refer to, and the IICRC’s own position that categorising weather-driven water requires inspection and information gathering rather than a blanket rule — which is the opposite of the "all flood water is Category 3" shorthand common in contractor marketing.

    Note: This is the association’s position statement, not the ANSI/IICRC S500 standard itself, which is a paid document this site has not read. Nothing here should be taken as a verified quotation of S500.

  9. USDA Forest Products Laboratory, Wood Handbook, Chapter 14: Biodeterioration of Wood (General Technical Report FPL-GTR-282 (2021 edition)) Checked

    The wood moisture content and temperature ranges at which decay fungi become active, which is what separates a surface mold problem from structural rot.

  10. Oregon Department of Emergency Management, Oregon Department of Emergency Management Activates Emergency Coordination Center to Level 3 in Response to Atmospheric River Checked

    That the state activated its Emergency Coordination Center to Level 3 — Regional Response at 4:00 p.m. on December 17, 2025 ahead of an atmospheric river, and that National Weather Service flood watches covered fourteen counties including Multnomah, Clackamas and Washington.

    Note: December 2025 carried two separate atmospheric rivers in this region, one around December 8–11 and one around December 15–21. This release belongs to the second. Nothing on this site attributes a specific stream gauge reading to either event: the Johnson Creek reporting available describes it approaching minor flood stage rather than cresting above it, and no primary gauge record was obtained.

Sources last checked between and ; the date beside each one is when it was last opened. Where a figure comes from a document that is revised on a schedule, the edition or version is named above so you can confirm it against the current one yourself.

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