DIY may fit a limited, clean, accessible spill
Small amounts of clean water on surfaces that can be fully dried may be manageable with ordinary cleanup, assuming no electrical or structural hazard exists.
Hidden moisture changes the situation
If water reached wall cavities, flooring systems, cabinets or multiple rooms, it can be difficult to verify complete drying by appearance alone.
Contaminated water is a different category
Sewage and outdoor floodwater warrant more conservative handling and personal protection.
Safety overrides convenience
Standing water near electricity, unstable ceilings and large releases are reasons not to treat the loss like a normal household spill.
Talk through the situation by phone
Describe the source of the water, the affected area and whether the water is still entering the property.