Red River Compact Commission
The purpose of the Red River Compact is to promote interstate comity and remove causes of controversy between each of the affected states by governing the use, control and distribution of the interstate water of the Red River and its tributaries. (Ark. Code Ann. § 15-23-501 et seq.) Member states include Arkansas, Oklahoma, Texas, and Louisiana. The Compact is also intended to serve as a basis for state or joint planning action because it identifies and provides an equitable apportionment of water among the signatory states by defining reaches or subdivisions of the Red River. It provides an active program for the conservation of water, protection of lives and property from floods, improvement of water quality, and development of navigation and regulation of flows in the Red River Basin.
You can read the compact by going to this free, publicly accessible version of the Arkansas Code and and searching for "Red River Compact."