Volusia County Blue Spring and Blue Spring Run provide critical habitat for the St. Johns River population of the endangered Florida manatees. Minimum flows for Volusia Blue Spring are being determined based on allowing continuing future expansion of the over-wintering manatee population. In addition to manatees, many other protected aquatic resource values exist in Volusia County Blue Spring, including water quality, pollutant assimilation functions, fish and wildlife populations, and human uses. Based on existing physical, chemical, and biological data from Blue Spring and Blue Spring Run, WSI assessed the effects of reduced spring flows on the ecology of the spring run, including submerged aquatic vegetation and wildlife. Quantitative metrics were proposed for a total of 46 water resource values including human use, fish and wildlife support, and fish passage. Correlation analyses were conducted with existing data to determine predictive relationships between spring flow and each water resource value metric. An ecosystem model was proposed to illustrate the most important relationships between the spring flows and the dependent aquatic ecosystem structure and function. Where existing data were not available to quantify the relationship between spring flow and aquatic resource values, additional water quality and ecological monitoring was recommended.

Based on this analysis, WSI determined that protection of the manatee habitat is likely to provide adequate protection from significant harm for all other applicable aquatic resource values at Volusia County Blue Spring and Blue Spring Run. WSI staff continue to provide support to the SJRWMD on this project by leading long-term monitoring efforts to assess protection of the water resource values.

Silver Springs is the largest spring in Florida (based on flow volume) and the most visited (based on economic value). It is also the most studied with a record of physical data collection extending back nearly 100 years and extensive ecological data encompassing the past 50 years. Silver Springs also faces the same crises in terms of rapidly increasing nitrate concentrations as do many springs in the state. For these reasons the SJRWMD with funding provided by the Florida Springs Initiative contracted with WSI and the University of Florida Department of Fisheries and Aquatic Sciences (UF) and utilized in-house staff to conduct a comprehensive one-year study of the environmental conditions in Silver Springs and the upper Silver River to allow a quantitative analysis of changing conditions over the past 50 years and predictions of possible changes over the next 50 years. WSI was selected for this project because of Dr. Knight’s specific doctoral research experience at Silver Springs in 1978 – 1980 and because of the firm’s extensive experience with evaluating the environmental effects of nitrogen in aquatic and wetland ecosystems.

In addition to serving as the co-principal investigator with responsibility for reviewing the work of the UF and SJRWMD project collaborators, WSI was specifically tasked with sampling and assessing hydrologic changes and climatic factors, changes in underwater light transmittance, a broad suite of water quality parameters, aquatic macroinvertebrate emergence rates, floating macrophyte export rates, particulate carbon export rates, and whole ecosystem metabolism (primary productivity and community respiration) based on upstream-downstream dissolved oxygen changes. WSI was also responsible for reviewing and summarizing all historic data for Silver Springs, designing and constructing an ACCESS™ database for all project data, and for developing models for assessing the future conditions in Silver Springs based on current rates of changes to surrounding land uses.

Wekiwa, Rock Springs, and their associated spring runs are important natural resources in the Orlando metropolitan area. As such they are highly prized by the public and protected as parks and as Outstanding Florida Waters. Although these spring runs may have historically been affected by agricultural development, current stressors are increasingly derived from urban development in their respective springsheds.

The 2004 Wekiva River Protection Act (WRPA) mandated an analysis of applicable Pollutant Load Reduction Goals (PLRGs) for these spring-based ecosystems as mitigation towards the construction of a multi-lane expressway in the watershed. WSI was contracted by the SJRWMD to conduct a key component of this Wekiva System PLRG analysis. The WRPA mandated a short window for completion of this study and WSI relied on quantitative but rapid methods for analysis of entire ecosystem functions in the Wekiva River and Rock Springs Run. Upstream and downstream river segments were selected to provide ecosystem data as a function of differing flow and nutrient load conditions, and two reference spring runs, Alexander Springs Creek and Juniper Creek, both located in the Ocala National Forest, were selected as control sites as they have experienced minimal anthropogenic impacts.

Following literature review and work plan completion, WSI successfully implemented the ecological study of the four spring-based rivers. Field studies included monitoring of light, rain, stream level, flow, and discharge, comprehensive water quality sampling, oxygen diffusion rates, physical and chemical sediment properties, plant community characterization, light transmittance sampling, analysis of nutrient assimilation rates, macrophyte and particulate export measurements, whole ecosystem metabolism studies, and mesocosm experiments assessing growth rates of submerged aquatic macrophytes and filamentous algae in response to ambient nutrient and light conditions. WSI completed the entire project on schedule and prepared the data analyses and reports in a timely manner. Following the initial PLRG analysis, a subset of this work was continued for an additional year to allow comparison of ecological functioning of these spring-fed rivers over two annual cycles.

WSI prepared a detailed white paper for the SFWMD concerning nutrient and flow issues in the Caloosahatchee River/Estuary. This project included an in-depth review of published information about the environmental conditions in the river and estuary, including climatic conditions, flows, water quality, nutrient assimilation, flora, fauna, and impaired water status. This information was summarized in a white paper for distribution to public and private interested parties and subsequently served as the framework for a detailed technical workshop held in Ft. Myers on September 22, 2005. Dr. Knight with WSI was a presenter at the workshop and highlighted existing water quality conditions and potential technologies available for reducing future nutrient loads to the estuary.

The C-43 West Storage Reservoir Project is an important component of the Comprehensive Everglades Restoration Program (CERP) and is intended to support Caloosahatchee Estuary restoration by attenuating peak stormwater flows during the wet season and providing additional base flow for estuary health during the dry season. As well, the reservoir will capture and store regulatory releases from Lake Okeechobee, further reducing the number and volume of harmful freshwater discharges to coastal estuaries during the wet season.

The SFWMD implemented the C-43 Storage Reservoir Test Cell Program to evaluate seepage rates for the full-scale project. WSI was hired by the District’s C-43 WSR contractor, Stanley Consultants, Inc., to provide a limited evaluation of water quality benefits and liabilities associated with reservoir start-up and operation. WSI prepared a detailed report from water quality monitoring activities in the C-43 West Storage Reservoir Test Cells during 2006 and 2007.

WSI has provided expert consulting services on surface water quality in and around three up-scale developments in southwest Florida. Each of these projects is tasked with matching pre- and post-development loads of water-borne pollutants leaving the sites. WSI assessed existing and future land uses, unit pollutant loading rates, effectiveness of stormwater management options, and additional pollutant assimilation in on-site natural wetlands. This work included a state-of-the-art assessment of the water quality treatment performance of stormwater best management practices including wet detention and constructed wetlands.

While with CH2M HILL in Gainesville, Dr. Knight served as project manager and expert witness for the City of St. Petersburg, Florida for the St. Petersburg Wellfield Water Use Permit Hearings. Dr. Knight directed and helped conduct a variety of environmental studies related to providing evidence for the hearing. He worked on three wellfields: Cosme-Odessa, Section 21, and South Pasco to quantify aquatic, wetland, and upland ecological changes, assess vegetative changes in and around the wellfields (upland and wetland plant communities as well as phytoplankton populations in the lakes) and assess populations of wetland-dependent wildlife including birds, small mammals, macroinvertebrates, reptiles, amphibians, and fish. Dr. Knight was assisted by Mr. Clarke in quantifying the impacts of draw-down on cypress tree growth rate changes, invasions of exotics such as melaleuca, ecological succession due to changing wetland water regimes, and ecological changes adjacent to operating wellfields. As an expert witness, Dr. Knight was successful at explaining complex ecological consequences of wellfield operations to the administrative hearing officer.

Information collected from these studies was incorporated into a recommended approach for setting minimum flows and levels in aquatic and wetland systems in southwest Florida. This proposed “Unified Approach” recognized the link between water regime (depth and duration of standing water) and the ecological functions of aquatic and wetland systems. Existing water regimes need to be maintained to protect existing ecological functions, including plant communities and wildlife populations. In many cases new ecosystems have developed in response to historic water regime changes. Reversing those historic changes is frequently not practical from a cost standpoint and will often result in replacement of newly adapted ecosystems. These considerations can be included in setting appropriate minimum flows and levels that protect water resource and human-use values of affected water resources.