This interaction between elevation and water is particularly evident in Long Pine Key in Everglades National Park. Sections of Long Pine Key flood anywhere from 20 to 60 days per year.[10] However, the hydrology of south Florida has changed drastically since the 1950s due to urban expansion and increased agricultural practices. The limestone of the Miami Rock Ridge was perfect for development, and subsequent drainage has led to a significant decrease in the water table.[11] A lowered water table may harm sites prone to seasonal flooding and may increase the risk of salt-water intrusion. The Comprehensive Everglades Restoration Plan is an attempt to restore the hydrology of the Everglades.[12]