If at the time of dissolution there is any outstanding indebtedness of the district the legislative authority of the city, where the limits of the district lie wholly within the corporate limits of a city, and in all other cases the board of supervisors of the county in which the whole or greater portion of the district is situated are ex officio the board of directors of the district for the purpose only of the levy and collection of taxes for the payment of the indebtedness of the district existing at the time of dissolution and the interest thereon. The board or legislative authority shall levy the taxes and perform such other acts as are necessary to raise the money

necessary for the payment of the indebtedness and the interest thereon.