Gray water contains a significant level of contamination and has the potential to cause discomfort or sickness if consumed by or exposed to humans. Gray water may contain chemicals, bio-contaminants (fungal, bacterial, viral, algae), or other contaminants. Examples include: discharge from dishwashers or washing machines, overflows from washing machines, overflows from toilet bowls with some urine (no feces), sump pump failures, seepage due to hydrostatic pressure, broken aquariums, and punctured water beds. Gray water that remains untreated for longer than 48 hours may escalate to Category 3.

Since you should notify your insurer soon as possible after the flood, it’s a good idea to keep your insurance company and local agent’s phone number in your always-ready emergency bag. (Note that the NFIP works through private insurance companies, so you contact your insurer just as you would for any other type of claim). In cases where a flood has affected a region or community, your agent may be busy handling his or her own flood issues. In that case, contact the insurance company’s headquarters. 
When a disaster of this magnitude occurs, the first things a plant will need are lighting and pumps. This requires the use of on-site generators and temporary power connections. It's highly recommended to not allow the plant distribution system to be back-fed. If a motor is required to turn a pump, a portable motor starter fed by the generator should be installed on a temporary panel next to the motor.
An insurance policy may or may not cover the costs associated with water damage and the process of water damage restoration. While a common cause of residential water damage is often the failure of a sump pump, many homeowner's insurance policies do not cover the associated costs without an addendum which adds to the monthly premium of the policy. Often the verbiage of this addendum is similar to "Sewer and Drain Coverage".