Everglades National Park

a) Quantity and quality of water entering the property;

b) Urban encroachment;

c) Agricultural fertiliser pollution;

d) Mercury contamination of fish and wildlife;

e) Lowered water levels due to flood control measures;

f) Damage from hurricanes. 

On 5 March 2010 a report was submitted by the State Party on the state of conservation of the property. This report describes the threats to the Everglades’ aquatic ecosystem, briefly reports on progress in implementing the nine corrective measures developed when the property was previously included in the List of World Heritage in Danger, considers the property’s vulnerability to climate change and sea-level rise, and requests the World Heritage Committee to consider re-inscribing the property on the List of World Heritage in Danger. The State Party also proposes to undertake a number of additional water infrastructure projects in order to fully restore and protect the property’s Outstanding Universal Value.

a) Alterations of the hydrological regime

The State Party reports that water inflows to the property have been reduced by up to 60% due to water flow diversions to promote agricultural and urban development upstream of the property. This reduction in water flow has caused significant damage to the ecosystem.

Progress on the corrective measures associated with this threat is reported as follows:

- Raising and bridging the Tamiami Trail, adding new conveyance and seepage management features and revising water management observations to increase water volumes and improve flow distributions to the property: The State Party recalls that the National Park Service has worked with the Army Corps of Engineers to modify the Central South Florida project, in order to increase critical water flows to the property. This project supplies water and flood control regionally and is responsible for much of the 60% reduction in water availability for the property. To date, efforts to implement the above corrective measures developed when the property was on the List of World Heritage in Danger have resulted in minimal improvements in water volumes and flow distribution. However, the State Party notes that in December 2009, the construction of a one mile bridge and raising of the Tamiami Trail roadway began as part of the second phase of the Modified Water Deliverers (MWD) project, and is expected to be completed in 2013. The roadway improvements will allow the third phase of the MWD project to go forward, i.e. construction of new water conveyance features to move water through the upstream conservation areas and into Northeast Shark River Slough. However, the State Party notes that improvements to water flow under the MWD project will be limited as they will only increase water levels by a small amount.

The State Party concludes that even with the above measures in place by 2013, additional bridging and roadway improvements will be necessary to eliminate the flow impediment created by the Tamiami Trail in the 1920’s and redirect the inflows to the historic eastern flow-way, thereby increasing water depths and flooding durations in Northeast Shark River Slough, and eventually leading to the return of wading birds. In 2009, the United States Congress directed the National Park Service to consider the feasibility of additional bridging on the Tamiami Trail in order to allow unconstrained water flows beneath the highway, which will restore habitat with the property. A Feasibility Study on this issue is expected to be available in April 2010. This new infrastructure project, combined with some additional upstream corrective measures, could begin to return the property back to pre-drainage conditions in the early 1900’s.

b) Impacts from adjacent urban and agricultural growth

The State Party reports that agricultural and urban expansion into lower lying lands along the western edge of the Atlantic Coastal Ridge have created demands for increased flood protection, which has had the result of causing significant drainage within the eastern wetlands of the property. Progress on the corrective measures associated with this threat is reported as follows:

- Complete the C-111 South Dade Project and C-111 Spreader Canal Project and revise water management operations to maintain higher water levels within Taylor Slough:The State Party reports that all the original South Dade Project features were completed in 2009 and have shown limited benefits for maintaining slightly higher marsh water levels. A new engineering report has recommended an expansion of the C-111 detention area northward to connect with features for the Modified Water Deliveries Project, which would flood mitigation flows to pass southward. The planned completion date for this work is 2014. In addition to the above features, the C-111 Spreader Canal Phase 1 project will construct similar detention areas and other seepage management features to maintain high water levels in southern Taylor slough (to be completed in mid-2012).

The State Party concludes that some unintended detrimental impacts including increased nutrient loadings, elevated phosphorous levels and exotic fish invasions have been associated with the C-111 South Dade Project, and that improved management should minimise these impacts in the expanded water detention features. The State Party notes that while the above projects are a necessary first step, restoration of substantially greater water inflows into Taylor Slough via the newly proposed Tamiami Trail improvement project will be required to re-establish natural ecological conditions.

c) Increased nutrient pollution from upstream agricultural activities

The State Party notes that more than 16,200 ha of the property’s wetlands show signs of eutrophication impacts, including reduced dissolved oxygen levels, loss of algal communities, loss of marl prairie habitat, reduced fish productive and loss of wading bird foraging habitat, and that the extent of affected wetland is increasing and compromising the structure and function of the property’s aquatic ecosystem.Progress on the corrective measures associated with this threat is reported as follows:

- Achieve compliance with the settlement agreement in United States v. South Florida Water Management District by further reducing phosphorous at its source and construction additional storm water treatment areas:The State Party reports that the settlement agreement, which is now in its 19th year of implementation has achieved significant progress with a 44% reduction in total phosphorous loads entering the property. However, the State Party notes that recent inflows along the Tamiami Trail in 2008 and 2009, while not exceeding the long-term phosphorous limit are currently right at this limit, which suggests that additional water quality improvements are required. The State Party is evaluating these options, including additional source controls and increasing the size of storm water treatment areas, but that an additional 8-10 years will be required for these measures to be implemented.

d) Protection and management of Florida Bay

The State Party notes that at present Florida Bay remains stressed from persistent hypersaline conditions, recurring algal blooms and die-off of sea grass. Most of these issues have been caused by reduction in freshwater inflows and the productivity necessary to maintain estuarine fish communities, which has resulted in a significant reduction in wading bird and marine shorebird communities. Progress on the corrective measures associated with this threat is as follows:

- Complete construction of the C-111 South Dade Project and the C-111 Spreader Canal Phase 1 project to reduce seepage losses and increase flows to the eastern basins of the property: The C-111 South Dade Project and the C-111 Spreader Canal Phase 1 Project are designed to create a nearly continuous groundwater ridge along the eastern border of Taylor Slough to retain water within this watershed and redirect flows to the central region of Florida Bay. The State Party considers that in the future it will be important to focus on increasing the volume of freshwater delivered, as well as their quality, timing, and that substantial inflows into Northeast Shar River Slough will be required to restore freshwater inflows to the Bay, reduce salinity and restore the estuarine ecosystem. The State Party notes that a planned Florida Bay Feasibility Study is on hold and should be reinitiated as the above projects progress, in order to evaluate the cumulative effectiveness of the planned restoration efforts and any additional improvements that may be needed to restore the Bay.

e) Vulnerability assessment to climate change and sea-level rise

The State Party considers that restoring the Everglades ecosystem is the best way to ensure that the property is resilient to climate change. The report notes that Everglades National Park is undertaking monitoring and research to address many of the identified species and communities at risk from climate change, and is examining modelling and decision support options to bring integrated, science-based adaptive management to climate change and sea level rise issues facing the property. Restoring historic freshwater flows can serve as a climate change adaptation tool by providing the freshwater necessary to offset (at least partially) saltwater transgressions as sea level rises. The State Party concludes that maintaining freshwater habitats for as long as possible gives species critical time to adapt or succeed gradually.

f) List of World Heritage in Danger

The State Party recalls that the property was inscribed on the List of World Heritage in Danger in 1993 due to the impacts of Hurricane Andrew and substantial decreases in water inflow to the property and deterioration of its ecosystem due to nearly five decades of the operation of the Central and South Florida project, combined with worsening water quality due to urbanisation and agriculture. While the World Heritage Committee decided to remove the property in 2007 due to efforts to restore the park and its wider ecosystem, the State Party considers that these goals have not been fully implemented, nor are fully underway, and that the restoration goals for increased water quantity and flow and increased water quality are not realised. The State Party notes that without the implementation of the planned Everglades’ restoration projects, the property will continue to experience irreversible loss of its values and integrity.

The State Party reports that key ecological indicators have continued to deteriorate. Wading bird population sizes are only 5-10% of the levels observed in the early 1900’s, and algal blooms lead to mortality of estuarine species, including sea grasses, sponges and corals, and degrade the habitats for important marine species such as pink shrimp. Moreover, populations of large predators are decreasing, including those of the threatened American crocodile.

As a result of the continuing degradation of the property, evidenced through monitoring of key ecological indicators, the United States recommend that the World Heritage Committee consider relisting the property on the List of World Heritage in Danger for a short period of time until the corrective measures to improve water quantity and flow are implemented, and to allow the State Party the opportunity to monitor the biologic response to determine if the property’s ecosystem responds positively to these measures. As part of this process, the State Party requests a joint IUCN/ / World Heritage Centre mission to evaluate the state of conservation of the property in 2010, and to assist the National Park Service and its partners in developing a desired state of conservation for the removal of the property from the List of World Heritage in Danger. 

The World Heritage Centre and IUCN commend the State Party for requesting the World Heritage Committee to consider re-inscribing the property on the List of World Heritage in Danger. They concur with the State Party’s analysis that the threats to the property continue to be serious, and recall IUCN’s view, expressed at the World Heritage Committee in 2007, that the property remains in ascertained danger of losing the values for which it was inscribed on the World Heritage List. While some progress has been made towards meeting a number of the original nine corrective measures established by the Committee, many of these have not been implemented to date, as acknowledged by the State Party

The World Heritage Centre and IUCN agree with the State Party that the current nine corrective measures are insufficient to secure the long-term restoration and preservation of the Everglade’s aquatic ecosystem, as evidenced by the limited improvements in water level occasioned by the implementation of some of the corrective measures. They also welcome the State Party proposal to consider the feasibility of additional bridging on the Tamiami Trail in order to allow unconstrained water flows beneath the highway, and restore historical water flow volumes and pathways through the property, thereby securing long-term ecosystem function. They consider that the implementation of these projects is critical to ensuring the restoration and preservation of the Outstanding Universal Value of the property. Therefore, they strongly urge the State Party to finalise the Feasibility Plan for additional bridging on the Tamiami Trail, as well as the plans for additional upstream corrective measures, and to reinstate the planned Florida Bay Feasibility Study. Copies of these feasibility studies and plans should be provided to the World Heritage Centre as soon as they become available.

With regard to the threat of climate change and sea level rise, the World Heritage Centre and IUCN endorse the State Party’s view that the effective restoration of the Everglade’s aquatic ecosystem would be the single greatest contribution to mitigating these. Therefore, the implementation of an expanded restoration project is essential to not only contribute to restoring the property’s Outstanding Universal Value, but also preserve it over the medium and long-term.

Furthermore, the World Heritage Centre has asked the State Party to keep it informed of any impacts from the Gulf of Mexico Oil Spill that begun in April 2010, and will inform the world Heritage Committee accordingly.