La. Stat. tit. 38 § 3054
Limits of district may be extended to include one or more additional parishes affected by ground water resources common to East Baton Rouge Parish such additional parish or parishes are hereinafter referred to as "Additional Parish". No additional parish shall be included within district except upon approval thereof by the governing authority of additional parish and commission. Notice shall be given of a public hearing to be conducted by governing authority of additional parish in accordance with the requirements therefor as above required for creation of district hereunder. The action of governing authority approving inclusion of additional parish within district shall provide for appointment of two citizens and residents of additional parish to serve as members of commission.
La. R.S. § 38:3054