W. Va. Code § 22C-1-21
The exercise of the powers granted to the authority by this article will be in all respects for the benefit of the people of the state, for the improvement of their health, safety, convenience and welfare and for the enhancement of their residential, agricultural, recreational, economic, commercial and industrial opportunities and is a public purpose. As the operation and maintenance of water development projects are essential governmental functions, the authority is not required to pay any taxes or assessments upon any water development project or upon any property acquired or used by the authority or upon the income therefrom. Such bonds and notes and all interest and income thereon are exempt from all taxation by this state, or any county, municipality, political subdivision or agency thereof, except inheritance taxes.
W. Va. Code § 22C-1-21