Water is one of the four basic risks covered under home contents insurance. Coverage for water includes damage caused by water and similar liquids from pipes and connected machines or installations such as fish tanks, waterbeds or ornamental fountains. Indemnification is also paid in case of damage caused by to rain, snow and meltwater. The water may have entered through outdoor drains, gutters, the roof itself or leaky windows. Damage to the interior of a building is covered if it is caused by backwater from the drainage system, ground water or slope water running underground. Damage caused by heat exchangers is usually also included, but sometimes this requires additional provisions. Loss resulting from flooding is considered damage due to natural hazards and therefore also covered under home contents insurance.