A municipally owned utility that owns or operates transmission and distribution facilities shall file with the commission tariffs implementing the open access rules established by the commission under Section 39.203 and shall file with the commission the rates for open access on distribution facilities as set by the municipal regulatory authority, before the 90th day preceding the date the utility offers customer choice. The commission does not have authority to determine the rates for distribution access service for a municipally owned utility.
Tex. Util. Code § 40.058