Redundant
From 'Vocabulary' part of The ABC Of Plain Words by Sir E Gowers (1951)

This is an imposing word and, no doubt for that reason, is used in senses that it will not bear. The idea of too much is inseparable from it; "superabundant, superfluous, excessive", is what the dictionary says. To treat it as meaning merely inappropriate is wrong.

The Authority are now reluctant to proceed with the provision of services for a 10,000 population in case their work becomes redundant due to the subsequent need for catering for a larger population.

It is nonsense to say that provision for a population of a certain size might become superabundant if it were subsequently necessary to cater for a larger population. For this use of due to, see Due to.