Okla. Stat. tit. 11 § 17-110
For the purpose of creating a capital improvement fund and expending money therefrom, capital improvement shall mean all items and articles, either new or replacements, not consumed with use but only diminished in value with prolonged use, including but not limited to roads and streets, drainage improvements, water and sewerage improvements, machinery, equipment, furniture and fixtures, all real property, all construction or reconstruction of buildings, appurtenances and improvements to real property, the cost and expenses related thereto of rights-of-way or other real property, engineering, architectural or legal fees, and payment for improvements for which subsequent reimbursement is made to the capital improvement fund.
Okla. Stat. tit. 11, § 17-110