Wetland Restoration in the Northern Everglades: Watershed Potential and Nutrient Legacies.

The Northern Everglades encompasses the Kissimmee, Caloosahatchee and St. Lucie river watersheds and their associated estuaries linked to Lake Okeechobee in south-central Florida.  In 2007 the Florida legislature strengthened protection of this region with the Northern Everglades and Estuaries Protection Program (NEPP). The legislation recognizes that changes in land use, construction of drainage associated with the Central and Southern Florida Project, and the loss of water storage, adversely affected hydrology and water quality of Lake Okeechobee and its associated estuaries.  To address these problems, the legislation adopted a comprehensive watershed-based approach to be coordinated with the Comprehensive Everglades Restoration Plan.  Restoration plans call for projects that improve both hydrologic functions, including the quantity, timing and distribution of surface water, and water quality, focusing mainly on eutrophication due to excess nutrient loads (N and P).  Aspects of the NEPP that address wetland restoration in the region include: isolated wetland restoration projects; voluntary water storage on private lands; construction of public works constructed wetland or hybrid wetland projects; and preservation, and restoration or creation of wetlands on agricultural land.  In addition to these state-funded programs, federal programs, such as the USDA Wetland Reserve Program, and the proposed Everglades Headwaters National Wildlife Refuge support large scale wetland restoration throughout the region.  Research supporting these various efforts has examined the effects of treatment wetlands on nutrient storage and removal, and the potential for water retention projects on private lands to contribute to watershed restoration goals.  Mixed results from these studies reveal that projects vary widely in their capacity to retain water or remove nutrients, and that projects need to carefully consider the effects of nutrient legacies in the landscape and site-specific hydrologic processes.  The interaction of surface and groundwater and capacity for soil to bind P are major factors controlling outcomes in the region.