Notwithstanding any other provision of the law to the contrary, the board may hold executive sessions in conjunction with any regular or special meeting and maintain confidential information and records limited to matters concerning interstate claims to the use of Colorado River system waters in judicial proceedings, administrative proceedings, and negotiations with representatives from other states or the federal government. Whenever the board holds an executive session in conjunction with any regular or special meeting or maintains as confidential any information or records hereunder, the board shall make an affirmative finding in its public minutes that the holding of an open meeting or the disclosure of the information or records to the public would substantially impair the performance by the board of its statutory duties. At the end of the minutes of each meeting of the board shall appear the certificate of its executive secretary that the meeting was held in accordance with the provisions of Article 9 (commencing with Section 11120) of Chapter 1 of Part 1 of Division 3 of Title 2 of the Government Code and Sections 12516 and 12519 of the Water Code.