After two catastrophic hurricanes in 1926 and 1928 that caused Lake Okeechobee to breach its levees and killing thousands, the government began to focus on controlling the floods rather than drainage.
The government created the Okeechobee Flood Control District in 1929. It was financed by both state and federal funds. In 1928, President Herbert Hoover ordered the Army Corps of Engineers to assist the communities surrounding the lake after he toured the area.
A dike 66 miles long was built around the southern edge of the lake between 1930 and 1937. Legal limits of the lake between 14 and 17 fee were declared when the control of the Hoover Dike and Lake Okeechobee were delegated to federal powers. At the same time, a massive canal of 80 feet wide and 6 feet deep through the Caloosahatchee River was also constructed. This enabled the excess water from the lake to leave through the canal. The cost of the entire project was $20 million. After the dike and canal were built, sugarcane production soared, and the population from the small towns surrounding the lake rose from 3,000 to 9,000.
In 1930 there was an extended drought and immediately the effect of the Hoover Dike was seen. With the wall prevented water from leaving the lake, and canals and ditches removing other water, the Everglades became parched. Salt ocean water intruded into Miami’s wells and the peat in the Everglades turned to dust.
When the salt ocean water intruded into Miami’s wells, they brought in an expert to explain why. He discovered that the water in the Everglades was the area’s groundwater, but here, it appeared on the surface.
A fire in Everglades in 1939 burned over a million acres and the black clouds of peat and sawgrass hung over Miami. The scientists who took soil samples before the draining did not take into account the organic composition of peat and muck that make it prone to soil subsidence when it becomes dry. Bacteria that occurs naturally in the Everglades peat and muck assist with the process of decomposition under water. Generally, this is a very slow process partially due to the low levels of dissolved oxygen. The bacteria interacted with much higher levels of oxygen in the air, rapidly breaking down the soil when the waters levels became so low. This left the peat and muck at the surface. In some areas, homes had to be moved to stilts and 8 feet of soil was lost.