 A massive canal 80 feet ( 24 m ) wide and 6 feet ( 1 @.@ 8 m ) deep was also dug through the <unk> River ; when the lake rose too high , the excess water left through the canal to the Gulf of Mexico . <unk> trees were planted along the north shore levee : Australian pines , Australian oaks , willows , and bamboo . More than $ 20 million was spent on the entire project . Sugarcane production soared after the dike and canal were built . The populations of the small towns surrounding the lake jumped from 3 @,@ 000 to 9 @,@ 000 after World War II . 
