The World's Largest Reclaimed Water-to-Wetlands Project: A Decade Later

Introduction The largest reclaimed to water wetlands system in the world was placed into operation over a decade ago in Panama City Beach, Florida. The 3,000-acre Conservation Park (Park) site has been a success story for the City of Panama City Beach (City) in multiple ways including surface water nutrient reductions, ecological restoration, new parks and recreation facilities, eco-tourism, and public education. At the same time, with over 10-years of operation, the City has a better understanding of the Park's nutrient uptake performance as well as made improvements to the Park and collected different lessons learned. Objectives This presentation explains the system operations over the last 10-years with performance data associated with nutrient uptake by the receiving wetland system and quantified reporting of ecological habitat improvements. Information related to system facilities and improvements implemented over the last 10-years along with lessons learned since implementation will be presented. Status The City achieved 100% reclaimed water use in the fall of 2012 with their public access irrigation and reclaimed water to wetlands systems. The flows from the City's Water Reclamation Facility (WRF) to the wetland system have ranged between 3 - 12 MGD over the past 10-years and have typically been 1.5 times the flow to the City's public reclaimed system. Nutrient concentrations leaving the Park have been tracked in effluent leaving the WRF and at the discharge point from the Park and show the nutrient levels 25% to 50% below those observed in the WRF effluent. Based on quarterly sampling, the total nitrogen (TN) and total phosphorus (TP) have remained below the permitted discharge limits. The Park has also become established as a destination for locals and tourists with top rankings on trip websites such as TripAdviser and AllTrails as well as the location for guided bird walks. In addition, the City has implemented a program to restore nearly 30% of the site from silviculture to it's natural habitat through physically removing evasive plant species, natural plants and tree plantings, and incorporating control burns. Methodology The hydraulic loading of the eight (8) natural wetland cells on site is based on their natural composition, function, hydroperiods, and habitat value and sized for up to a maximum flow of 32 MGD. All the cells are interconnected through various surface water interactions ultimately draining to a single location in the northern most basin. Each wetland cell was designed and constructed with the unique ability to control the hydraulic loading to maximize storage capacity based on WRF flows with lessons learned in topographic mapping of the drainage basins. The City has taken extensive steps to restore site habitat from when the lands were primarily used for silviculture (i.e., to grow trees) and fast-growing slash pines were densely planted in replacement of upland and wetland habitat. The City determined several prudent ecological activities should be incorporated, including tree harvesting, invasive plant thinning, native tree and wiregrass seedling planting, and prescribed burning. These efforts have made a marked difference on site where large areas of historic wire grass and long-leaf pine communities are now thriving with 269 acres documented as being restored or in process of restoration. In addition, along with the tree thinning and harvesting, a prescribed burning regimen was introduced to remove excessive buildup of organic detritus leading to devastating fires. Restoring periodic fires to the plant community has promoted growth of native species depending on fire to stimulate germination, provided additional sunlight through the canopy, and opened serotinous pinecones for seed dispersal. Lessons learned include routine maintenance for over 24 miles of hiking trails including over a mile of boardwalk through cypress domes is a necessity. At the same time, guided Audubon bird walks, volunteer, and recreational programs for Park guests are offered seasonally and in high demand since the site opened which brings an added need for routine Park maintenance. Findings and Significance The City's project is an excellent example of beneficial use of reclaimed water to replenish and restore native habitats. In addition, the performance of nutrient uptake in the receiving wetland system and the successful restoration of native habitat provide examples for other communities to consider in their efforts to remove surface water nutrient loads. Finally, the project has set an example for how a nature-based solution can be leveraged as a parks and recreation amenity and promote eco-tourism.