The 16 Water Planning Regions in Texas, as created by the Texas Water Development Board (TWDB), updated November 2014. In accordance with statute and administrative rule, the TWDB is required to review the Regional Water Planning Area (RWPA) boundaries every five years. The RWPA boundaries were initially created in 1998. The boundaries were reviewed and reaffirmed in 2001, 2006, 2011, 2016, and 2021 with no changes.