Basement floods are fairly common and can be caused by various circumstances. If you find yourself in a situation when your basement is flooded (even a small portion), there is a suggested protocol of action you should take to make the problem go away faster and more efficiently. It will take a bit of work, so be ready to get your hands dirty and possibly call into work to get some of the time off, if possible.

Shut Off the Power

You probably are aware that plugged in electronics and water do not mix. Do not enter a flooded room if the power is still on. This is not often what people first think of when they approach their flooded basement, but injuries and fatalities from flooded basements mixing with electrical systems have happened. Do not walk around unplugging electronics until you have completely shut off the power supply to that area. If your master power switch to the area is only accessed by going through the flooded room(s), call an electrical professional.

Wear boots and gloves

No matter the source of the water, it could be contaminated. Wear protection to keep you and your family safe from any contaminants as you enter the area. If necessary, also wear a face mask.

Dry Any Wet or Damp Objects

Any objects that are damp and can become damaged should be removed and placed somewhere to dry. This includes furniture, small objects, and d├ęcor.

Remove as Much Water as Possible

If the water flooded a hard surface, such as a wood or concrete floor, try soaking up the water with items such as mops. If the water is too deep to simply soak up, call a professional with the proper equipment to pump the water out.
If the flooded area is carpeted, you will need to lift the carpet to soak up the water underneath. This is a very important step, as water that is not removed beneath carpet can cause mildew, mold, contamination, rotting, and an awful stench, causing a need for a complete carpet replacement in the future.

Clean and Dehumidify

Clean any areas that may be contaminated to avoid the growth of contamination. Hopefully, you have access to a dehumidifier. If not, call a professional service who has access to these supplies and more.

The goal of steps 3, 4, and 5 is simply to remove as much moisture as possible from the room. Excess moisture even in small amounts can be highly damaging to your property.
Once you have dehumidified the entire area, you may begin putting your basement back together and taking steps toward preventing any repeat floods in the future.