Renting (hiring) desalination ...

Renting (hiring) desalination plants is usually possible for small capacity facilities (usually plants delivering 100,000 gallons/day or less of fresh water).  Based on current market conditions, If you need to rent the plant for a period longer than 8 months, the total rental costs will typically exceed the costs for buying the entire plant, so renting a plant will only be worthwhile if you need it for two to three months only.  The companies that offer package plants also offer renting such plants but usually this is not a large component of their business because except for emergencies, renting plants for long period of time (year or more) usually is several times costlier than buying the plant.