After Dardenne Creek floods, stay out of standing water, keep the power off to any wet area, and pump the water out before anything else. Sort clean water from sewage, photograph the damage and get the structure dried to readings. The creek flooded from O'Fallon to Saint Peters in December 2015 and reached major flood stage in July 2022.
Key takeaways
- Standing flood water is the first hazard, and it is entered only after the power to the area is confirmed off.
- Pumping comes before drying, because water left on the floor keeps feeding moisture into the materials.
- Creek water is treated as contaminated, and it is kept apart from any sewage that comes up a drain.
- The water path should be photographed before anything is moved, so the insurer and the crew see the same thing.
- Drying is done to readings, and equipment stays until the materials reach their dry standard.
Why is the creek such a serious flood source here?
Dardenne Creek runs from O'Fallon toward Saint Peters, and when heavy rain falls in its watershed the water can rise quickly. The December 2015 flood ran from O'Fallon into Saint Peters and closed Interstate 70 for two days. The July 2022 storm dropped more than a foot of rain across much of St. Charles County.
The creek is a local waterway, not a large river, but it can leave its banks in a short time when rain is heavy. Water moves across yards and low roads and finds the lowest openings in any house it reaches, including window wells, floor drains and the joint where the wall meets the floor.
The National Weather Service recorded the creek cresting at major flood stage in July 2022, and a levee was breached in that event. The USGS mapping of a 9.9-mile reach of the creek was built against the 2015 high-water marks, which is one reason the creek's flood path is well documented in this county.
What should you do in the first hour?
Stay out of standing water and keep children and pets away from it. If the water reached the electrical panel or an outlet, leave the power off until a qualified person has checked it. Move valuables up if it is safe, photograph the water line and call for help.
Flood water hides the ground, the drains, the curbs and the debris under its surface. Walking through it to reach the stairs or a car is one of the most common injuries during creek floods, and it is also how contaminated water reaches clothing and skin.
Once the water has dropped enough to walk safely and the power is confirmed off, document the scene. Take wide photos of each room, close photos of the water line and photos of each appliance that stood in water. Then call for the cleanup.
- Do not enter standing water until the power to the area is confirmed off
- Do not run a generator in a garage, basement or enclosed porch
- Photograph the water line before moving furniture or debris
- Keep the first wet materials you remove so they can be shown to an inspector
Why does pumping come before anything else?
Standing water keeps the floor and the lower walls saturated, and it feeds moisture upward into drywall, insulation and subfloor. Drying equipment cannot remove water that is still lying on the floor. Pumping the pool first limits how far the water wicks and gives the drying a fair start.
Water wicks into materials at the bottom of a wall, and the height of that wicking depends on how long the water sat. Pumping early keeps the wicking shorter, which is often the difference between removing a few feet of drywall and removing a whole lower wall.
Pumps and extraction tools work best when the discharge is kept away from the house and from neighboring yards. The crew sets the discharge line so the water does not flow back toward the foundation.
How do you tell creek water from sewage?
Creek water usually carries silt, soil and debris, and it can look brown or gray. Sewage has a strong odor, often shows solids or paper, and comes up through a drain rather than across the yard. If you are not sure, treat the water as sewage and keep people out of it.
Creek flood water is treated as contaminated because it has been over soil, lawn chemicals, road grime and whatever the flood picked up. Sewage is handled with stricter steps because its organisms can cause illness. Both kinds of water call for protective gear and careful handling.
A water test is done by the crew on arrival, and the result sets the handling for the rest of the job. Sewage-affected carpet and pad are generally removed, and porous materials that the sewage reached usually come out as well.
| Feature | Creek flood water | Sewage backup |
|---|---|---|
| Where it comes from | Yards, storm drains and the creek | Floor drains, toilets and sewer lines |
| Usual look | Brown or gray with silt | Gray or brown with solids or paper |
| Usual smell | Earthy or muddy | Strong sewage odor |
| Typical handling | Pump, remove silt, dry | Contain, remove porous materials, disinfect, dry |
| What to do first | Stay out, power off, photograph | Keep people out, stop using fixtures |
What happens to wet walls and floors after the water is out?
The crew maps the wet zone with meters and removes the materials that cannot be dried to a safe reading. Drywall and insulation are often the main removals. Floors and framing are dried in place where the readings allow, and each step is shared with the homeowner before it is made.
Floods leave a line on the wall and a band of wet material below it. Drywall below the line that soaked through is usually removed, while the framing and the bottom plate are read and dried. The crew cuts each opening only as far as the readings require.
Carpet and pad that held creek water are usually removed rather than cleaned, since they trap silt that is hard to rinse out. Hard flooring can often be cleaned and dried in place, once the readings confirm the subfloor is dry enough to keep.
What does the drying plan involve?
Drying uses air movers to speed evaporation at the surface and dehumidifiers to pull moisture from the room air. The equipment stays until each material reaches its dry standard, which the crew confirms with readings at each visit.
The plan starts with a set of baseline readings and a dry reference from an unaffected area of the house. The crew then compares the wet materials to that reference, and the plan ends only when the wet materials match it.
Flood-wet homes can have damp air for a long time, especially in lower rooms. The crew adjusts the equipment when the air stays humid, so the materials keep drying and the framing is not left damp inside the wall.
What should you keep for the insurance claim?
Keep dated photos of the water line and each room, the moisture readings, the sort list and the written scope. Keep every change order and every receipt. The insurer decides coverage under the policy, and a clear file makes that decision easier to review.
The water line in each room is one of the most useful pieces of evidence, because it shows the height and the spread of the water. Photograph it before any cleaning starts, and take a second set after the water has been removed.
The sort list records each item that was in the water and what was decided about it. Items that were kept should be photographed. Items that were discarded should be listed with the reason. The complete file is what an insurer will ask to see.
Frequently asked questions
How soon should cleanup start after a creek flood?
Start as soon as the area is safe to enter, because wet materials begin to degrade quickly. Pumping and drying are the time-sensitive stages. A crew can tell from the first visit which materials can be kept.
Can I clean up the silt myself?
You can remove loose debris once the area is safe, but silt holds moisture behind walls and under floors that a surface wipe cannot reach. Wear gloves and a mask, and let the readings confirm dryness before anything is closed up.
Should I turn off the water main?
If the flood is rising around the house and you can reach the main without entering standing water, closing it stops new water from a broken line. Do not wade into water to reach it.
Will the carpet be saved?
Carpet and pad that held creek water are usually removed, because they trap silt and moisture. Hard flooring is often kept after cleaning and drying. The crew explains which materials are affected.
Who decides whether the house can be lived in during cleanup?
The crew advises on which rooms are safe to use. The homeowner makes the final decision with that advice, and the crew says which rooms to keep closed while the work is underway.
What if the water came up through the floor drain?
Water that comes up a drain may be sewage rather than creek water. Treat it as sewage, keep people out and call for help. The crew tests the water on arrival and sets the handling from the result.
How long after a creek flood should I wait before rebuilding?
Wait until the readings show the structure has reached its dry standard. The time depends on the amount of water, the materials and the air. Rebuilding over damp framing can trap moisture and feed mold.
This guide is general information for St. Charles County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.