(a) The powers and duties of a district or governmental entity conferred by this chapter are public and governmental functions exercised for a public purpose and for matters of public necessity.
(b) The district or governmental entity and its personnel are immune from suit in tort for the performance of its duties under this chapter unless:(1) Immunity from tort is expressly waived in writing; or(2) The district or governmental entity acts with gross negligence.
(1) Immunity from tort is expressly waived in writing; or
(2) The district or governmental entity acts with gross negligence.