Mile 6 Gap Closure and Oxbow Restoration
Currently in the permitting phase of the project with state and federal regulatory agencies, the Jupiter Inlet District has designed plans to close a newly-formed breach and restore a nearby oxbow in a section of the Loxahatchee River's Northwest fork that is designated as a Wild and Scenic River.
The purpose of the project is to continue Jupiter Inlet District and Jonathan Dickinson State Park efforts to restore the historic flow and improve water quality within the Loxahatchee River by closing gaps and short circuits, often created or exacerbated by human activities, within the river’s Northwest Fork.
The effort to restore this area and return the river to its meandering flow is located upriver at mile 6, and is in accordance with the District's Loxahatchee River Management Plan with a focus on preservation and protection of important natural resources. As designed, it will help maximize residence time for the water as it flows South towards the inlet, improve water quality and reduce salt water intrusion upriver.
The gap, or breach, at mile 6 will be closed with native limestone rock that will also provide valuable hardbottom habitat for fish and wildlife. As part of the project, 1,156 cubic yards of sediment will be dredged from the shoal dredging area denoted on the map, and moved to fill behind the limestone rock at the gap and used to restore the oxbow. The design also calls for mangrove plantings in this area which will aid in stabilizing the sediment while creating new habitat for a broad range of species. Having identified isolated oyster beds in the area, all oysters will be moved and transplanted prior to construction to designated safety areas.
Both project sites are accessible by small watercraft, kayak, canoe and paddleboard. From the Jonathan Dickinson State Park Boat Ramp follow the watercourse downstream approximately 1,700 feet to reach the gap closure project site. From there, follow the watercourse downstream an additional 700 feet to reach the oxbow restoration maintenance project site.
The District has partnered with Jonathan Dickinson State Park in permitting and planning for this project, and officials are working closely with the Florida Department of Environmental Protection (FDEP), the U.S. Army Corps of Engineers (USACE), and a host of other partners working to preserve and protect the Loxahatchee River. The project is slated to begin in January 2022.
In the late 1990s, the Jupiter Inlet District completed a series oxbow restorations at four sites within Jonathan Dickinson State Park. Boat traffic had resulted in the destruction of mangrove shorelines and the breaching of narrow divisions between adjacent channels. These breaches effectively straightened the channel by shortcutting historical meanders, thereby allowing more direct tidal influence upon upstream reaches. Closure of the gaps improved water quality in stagnant areas, reduced organic deposition in isolated oxbows, decreased saltwater intrusion and increased retention time of freshwater runoff in the Northwest Fork.
For more information about the project, contact the District at (561) 746-2223.