Iowa Code § 360.8
The trustees of any township where such building has been erected or acquired by purchase, lease with purchase option, or by gift are hereby authorized to certify to the board of supervisors that a tax of not exceeding in any one year, thirteen and one-half cents per thousand dollars of assessed value, on the taxable property of the township, should be levied, to be used in keeping such building in repair, to furnish same with necessary furniture, and provide for the care thereof. Provided, that in counties with a population of seventeen thousand to seventeen thousand two hundred fifty, census 1960, where such buildings are of brick construction with at least one hundred thousand cubic feet of space, such tax may be twenty-seven cents per thousand dollars of assessed value on the taxable property. When such certificate is filed in the auditor's office, the board of supervisors shall levy such tax.
Iowa Code § 360.8