Provides a detailed description of the methods and techniques developed by GIS Associates and applied by the St. Johns River Water Management District to project future water demand to a 2030 planning horizon. Takes into account annual historic water use, annual variations in water use with respect to climatic variations, as well as the methodologies consistent with the recommendations of a water demand protection subcommittee.

Summary report findings are two-fold: Evaluates the potential for capturing excess water currently discharged to the Indian River Lagoon, for beneficial uses; and evaluates the reconnection of the C-25 and C-52 basins, potentially to convey available water supplies across the jurisdictional boundaries of the St. Johns River and South Florida water management districts.

Repeated herbicide use to control the proliferation of hydrilla can be costly over time, conflict with various uses and functions of water bodies, and result in increasing chemical resistance. The authors discuss the goal of surveillance-based management to identify and treat hydrilla before it expands to whole-lake coverage, thus avoiding expensive, large-scale herbicide applications.

Provides cost definitions/cost estimating and economic criteria to be used in the development of regional planning level water supply facilities’ cost estimates for the draft District Water Supply Plan 2010. Provides a consistent set of definitions and criteria for the development of comparable planning level life cycle cost estimates for all water supply alternatives.

Multiple consultants present first-year findings of a 25-year monitoring action plan for Blue Spring and Blue Spring Run, the site of a popular state park and a warm-water manatee refuge. Year one (October 2007–September 2008) summarizes the data analysis for water quality, in-stream recreation, algal thickness, stream condition index, two genera of snails, a diversity of fish and turtles, and manatee use. A few ecological parameters found to be most sensitive to flows are recommended to be added to the yearly, ongoing monitoring.

Planned wetlands restoration is an important component of the restoration of Lake Apopka. This study summarizes the nature and extent of pesticides and evaluates the remedial alternatives under a range of targets that would allow wetlands reestablishment on a large portion of the lands that had been drained for agricultural use from 1941 to 1985.

A steady-state groundwater model was developed to predict drawdown impacts in the confined surficial and Upper Floridan aquifers, as well as the unconfined surficial. A sensitivity analysis was performed for the model, and parameters were described based on hydrologic conditions existing in 1995. The steady-state groundwater model presented here could be utilized as the basis for other models to assess the impact of future groundwater withdrawals in the area.

Final report concludes that post-fasting organochlorine pesticide (OCP) concentrations in alligator blood can be a reliable indicator of environmental OCP levels. The authors recommend additional monitoring of alligator populations to provide further insight on the bioavailability of OCPs to piscivorous birds and other wildlife. Research of 408 alligators was conducted in 2008–2009 as a follow-up to a 2007 pilot study of the North Shore Restoration Area.

This report describes the methods used to recompute daily discharge of Silver Springs, near Ocala. Recomputed daily discharge values for the period 1948–2005 are compared with the historical (USGS) record. Hydrographs and summary tables are presented. Daily discharges are specific to a single reference station, located about 3,900 feet downstream from the main spring boils. Recomputation considers the effects of measurement location on rating-curve development. Also, new discharge rating curves based on head difference between the spring pool and the aquifer were used to recompute discharge values for the period 1948–2002.

Available hydrologic data including rainfall records, stream discharge records, and individual spring discharge measurements were compiled, reviewed, and compared, for the purpose of identifying long-term trends or underlying causes of changes in discharge. Stream discharge locations in the lower basin were consistent in data except for Riverside Landing, which showed a very large increase in measured flow relative to upstream measurements. Further investigation would be required for realistic hydrologic modeling to be developed.

The report documents the investigation of the Upper Ocklawaha River Basin as a potential water supply source, using annual streamflow records and historical records for the 38-year period from 1969 to 2007 from the Moss Bluff U.S. Geological Survey gage.

The report presents an estimate of the potential additional water supply yield, in addition to existing withdrawals, available from the St. Johns River at or above State Road 50.

The report compiles hydrogeologic and water quality data from the surficial aquifer system of Flagler, Brevard and Indian River counties to assess the feasibility of shallow Class V well concentrate disposal.

The report documents the work toward the goal to determine the estimated amount of potable-quality water offset that occurs when reclaimed water is used in place of potable water for irrigation.

This report documents the results of a feeding study to determine the potential for bioaccumulation of organochlorine pesticides in great egrets, to determine the potential for toxicosis and to evaluate the effects of fasting on tissue from these birds.

This report gives details about the health of aquatic vegetation in the St. Johns River’s lower basin and discusses changes in the vegetation.

The report describes the methodologies used by the District to project and spatially distribute population for water supply planning purposes.

The report documents establishment of minimum flows and levels for Blue Spring in Volusia County, the impact of groundwater withdrawals on average annual discharge to the spring and the development of alternative water supplies in Volusia County.

The report documents four studies regarding the improvements to water quality in the Upper Ocklawaha River Basin through the removal of gizzard shad.

Key hydrologic, water quality, and biological data are compiled and reviewed from a 2-year period to present a base evaluation of potential fatal flaws for a set of candidate alternative water supply project study zones along portions of the St. Johns River. Includes a discussion of mass balance analysis for each potential demineralization water treatment plant location, an evaluation of mixing zone feasibility for the potential outfalls, and the preparation and documentation of a mass balance spreadsheet model to estimate the effects of concentrate loading on the river.

Estimates are provided for comparison purposes considering 60% reuse, 75% reuse, and 100% reuse targets, for utilities looking for opportunities to maximize reclaimed water use to offset potable water supply and to reduce total maximum daily load discharges to the lower St. Johns River for compliance by year 2030. Results are presented against a base case scenario and a $300 million capital cost constraint to assist utilities in master planning. With utilities’ input, alternatives are represented in an optimized systems model — a water balance model that uses optimization techniques to estimate resulting infrastructure.

The feasibility of diverting storm water from the Nova Canal drainage basin system to supplemental regional reclaimed water systems, or other nonpotable uses, is documented. The study assesses the timing and quality of storm water that potentially could become available from canal system construction, taking into consideration the capital and unit production costs for facilities needed to recover storm water and for pumping to a storage or recharge facility.

Two management strategies are evaluated: active hydration and passive hydration, as feasible alternatives for avoiding or reducing impacts from groundwater drawdown effects in wetlands. A tabular summary of the results is presented, including a decision flowchart, to demonstrate the implementation of these strategies at four sites within SJRWMD.