(a) Money may be spent only for an expense included in the annual budget or an amendment to it.
(b) A district may not incur a debt payable from revenues of the district other than the revenues on hand or to be on hand in the current or immediately following fiscal year of the district.
(c) The board may not invest district funds in funds or securities other than:
(1) bonds of the United States;
(2) certificates of indebtedness issued by the United States secretary of the treasury;
(3) bonds of this state or a county, municipality, or school district of this state;
(4) shares or share accounts of savings and loan associations organized under the laws of this state or federal savings and loan associations domiciled in this state, if the shares or share accounts are insured by the Federal Deposit Insurance Corporation; or
(5) investments specified by Chapter 2256, Government Code.
(d) Subsection (b) does not apply to an expenditure related to, or an obligation issued or incurred in connection with, the financing of the construction or equipping of police facilities. Funds received by a municipality or other political subdivision of the state from a district for the financing of construction or equipping of police facilities may be used by the municipality or other political subdivision to secure the payment of bonds or other obligations issued by the municipality or other political subdivision to finance the construction or equipping of facilities described in Subsection (e), notwithstanding any law to the contrary.
(e) For purposes of this chapter, "police facility" means a police station or substation, police storefront, municipal court, jail, or minimum security facility.