Se7en Wetlands was once a phosphate mine that began in the 1920s. Part of the site was also used as phosphate clay settling ponds. The mine and all operations closed in 1984 and a few years later, the property was purchased by the City of Lakeland to become a Constructed Wetland Treatment System.
The 'Treatment Wetlands' have been in continuous operation since 1987 and now receive all of the City of Lakeland's treated wastewater, Lakeland Electric's reuse water, and Polk County's excess reclaimed water. In 2015, Tampa Electric Company built a pump station to beneficially reuse the water at their Polk Power Station. In 2018, Se7en Wetlands opened to the public as a new City of Lakeland park for passive recreation.