Restore Lagoon Inflow Project - Frequently Asked Questions
What is the Restore Lagoon Inflow (RLI) project?
Faculty researchers and graduate students at the Florida Institute of Technology (Florida Tech) in Melbourne have been contracted by the State of Florida, in support of a local project appropriation secured by Brevard County legislators, to study the potential effects of enhanced seawater exchange between the Indian River Lagoon (IRL) and coastal ocean.
This multi-year effort includes proposed installation of a temporary inflow demonstration system to help policymakers, agencies, and stakeholders determine if permanent enhanced seawater exchange should be considered to help improve the IRL ecosystem.
Why is this RLI project needed?
The health of the IRL is seriously imperiled, and Florida policymakers and agencies need more information and scientific perspective to help determine strategies to stabilize and restore the lagoon system. Multiple agencies are involved in efforts to reduce excess nutrients and improve lagoon water quality through a variety of projects, policies, and legislative initiatives.
By improving understanding and management of the IRL system, the RLI project results will also help to address several actions in the IRL National Estuary Program Comprehensive Conservation and Management Plan, including specifically addressing action “Connected Waters-5” which calls for a pilot / demonstration project to assess the benefits and risks of enhanced ocean exchange with the lagoon.
Has a permanent ocean water exchange structure been completed before?
Yes. The Destin Harbor pump site in Destin, Florida, has been operating since 1992 to increase ocean water circulation for improved water quality and prevention of fish kills resulting from low dissolved oxygen levels. Similar engineering initiatives to enhance ocean water circulation improved water quality in New York, California, and internationally. While the IRL ecosystem is different in many ways from these other systems, existing inflow projects highlight the potential benefits of using enhanced inflow to address declining water quality.
What are some of the areas being addressed?
Given the complexity of the lagoon ecosystem, the Florida Tech team is updating models and collecting geochemical and biological data to predict how the lagoon system may respond to enhanced inflow. Research areas include, but are not limited to, lagoon circulation and residence time, salinity and temperature gradients, water and sediment biogeochemistry, submerged aquatic vegetation cover (seagrasses), plankton and fish community structure, and inflow system engineering.
What are the steps involved in the RLI efforts?
The RLI demonstration effort is multi-phased. Agency and regulatory reviews and stakeholder input have guided project development and will continue to guide priorities and design of the proposed demonstration project. The initial phases summarized existing data and generated new environmental monitoring, modeling, and research data to improve understanding of the IRL and how the ecosystem might respond to enhanced seawater exchange. Candidate sites for a small-scale temporary inflow demonstration system were considered to provide an agency permitted demonstration of the feasibility and impacts of a larger inflow system. Next phases of the RLI project include permitting and final design, pump installation, operation and data gathering, pump decommissioning, and analysis and findings.
Where will the temporary inflow demonstration system be installed?
Upon review of the project’s Phase I results, Port Canaveral was selected as the preferred temporary inflow demonstration system site due in part to the relative lower cost and ease of access for a temporary demonstration system, as well as the existing exchange of seawater from port access at the locks. If a permanent inflow system is considered by policymakers in the future, a permanent installation site or sites along the lagoon system will need to be selected.
Would temporarily introducing more seawater into the IRL for the demonstration system raise the water level of the lagoon?
No. The inflow rates under consideration for the temporary inflow demonstration project would be controlled and limited in relative volume, with no perceptible impact on lagoon water level. Currently, the lagoon water level fluctuates with the tides, hurricane activity, and rainfall. Water levels also rise and fall seasonally in response to changes in Gulfstream circulation, which can result in a water level difference of as much as one foot from season-to-season.
Would pumping water only move a problem from one area to another?
Project models indicate enhanced inflow has the potential to reduce overall nutrient loads in the IRL by promoting natural processes that remove excess nutrients, with no predicted increase in nutrient loads in other areas of the lagoon. The proposed temporary inflow demonstration system was designed with a low pumping rate into a confined area of the lagoon while still providing a reliable test of enhanced inflow effects on lagoon water quality, nutrient removal, and plankton community dynamics.
Is there a danger that manatees and other wildlife could get trapped in an inflow system?
The temporary inflow demonstration system or any future infrastructure would be designed with safety features to prevent manatees and other wildlife from being trapped or impeded, including automatic and manual emergency shutoff features.
Would a permanently controlled inflow of seawater be beneficial?
There are not enough data or understanding to date to make an effects determination. Findings from the first two phases of the RLI project highlight the impaired state of the lagoon and the influence of oxygen levels on nutrient biodegradation. Initial results are consistent with published studies and suggest that enhanced ocean water inflow can decrease the concentration of nutrients that support the onset and proliferation of algal blooms.
The main benefits of decreased nutrient concentrations would likely result from changes to geochemical nutrient cycling from improved dissolved oxygen levels, with limited additional benefits from direct dilution by seawater. In the next project phase, construction of a temporary demonstration inflow system will help researchers extrapolate effects of a potential full-scale inflow system in the lagoon.
Would controlled seawater inflow solve the IRL’s water quality issues?
Enhanced seawater exchange would not, on its own, solve lagoon water quality issues. Rather, enhanced inflow could potentially augment ongoing and proposed efforts to reduce lagoon nutrient loads and improve ecosystem restoration efforts.
What could happen after the demonstration project concludes?
Once the temporary demonstration inflow system efforts conclude, data and assessments will be provided to policy makers, permitting agencies, and other stakeholders. If warranted, policy makers could begin steps toward installation of a full-scale permanent ocean water inflow system as a complimentary approach to restoring IRL water quality. This process would involve public discussions, site engineering, site selection, permitting, and natural resource monitoring.
What agencies and organizations are involved or will have an interest?
Permitting and consulting agencies and stakeholder organizations include the St. Johns River Water Management District, Florida Fish and Wildlife Conservation Commission, U.S. Army Corps of Engineers, Florida Department of Environmental Protection, IRL National Estuary Program, Port Canaveral, Brevard County, Indian River County, and several municipalities.
Has a new navigable inlet been proposed as part of the project discussion?
No new navigable inlet is proposed and the RLI efforts do not advocate for specific outcome.
Where can I find the information on the first two phases of the RLI project?
The RLI executive summaries and full reports are in the Reports Section of the Florida Tech Indian River Lagoon Research Institute site: https://www.fit.edu/indian-river-lagoon/.