Water Code §51.335

(a) A district proposing to exercise the powers and to perform the functions provided in this subchapter may include any part of areas already included within the boundaries of any political subdivision, governmental agency, or body politic of the state. (b) The district shall not usurp functions or duplicate a service already adequately exercised or rendered by the other governmental agency except: (1) under a valid contract with the other governmental agency; or (2) as provided by Subsection (c). (c) The district may finance, develop, and maintain recreational facilities under Subchapter N , Chapter 49 , even if similar facilities may be provided by a political subdivision or other governmental entity included wholly or partly in the district.