(a) The level of the pool shall normally be maintained at elevation 56.5 feet above sea level: Provided, That the level of the pool may be raised to not exceeding 58.5 feet above sea level at such times as may be authorized in writing by the District Engineer, Jacksonville, Fla., and subject to such conditions as he may specify.

(b) When, in the opinion of the District Engineer, an emergency exists requiring the lowering of the pool level to an elevation less than 56.5 above sea level either to safeguard the dikes or to increase the discharge from Lake Griffin in times of high water, the discharge past the dam shall be regulated in such manner as he may direct until he shall declare the emergency passed.