Water Management District Research Articles

WITHDRAWN: Restoring the Florida Everglades Comments on the current reservoir plan for solving harmful algal blooms and restoring the Florida Everglades

Preface This is an updated version of a review written by the author in April 2018 at the request of The Friends of the Everglades, an NGO based in Miami, Florida, on a plan developed primarily by the South Florida Water Management District (SFWMD) to mitigate coastal pollution that has resulted from discharges from Lake Okeechobee to the Gulf of Mexico and Atlantic coastline and eventually to “send the water south” to the Florida Everglades instead. This EAA Reservoir project was included by the U.S. Army Corps of Engineers in a 2018 U.S. Congressional bill that was approved. In May 2019, U.S. President Donald Trump pledged to spend $200 million to begin construction of this restoration, three times the amount requested by the state of Florida. While supported with enthusiasm by the Florida state legislature, the SFWMD, and some NGOs such as The Everglades Foundation, a change in leadership in the state of Florida after November 2018 elections and especially in the leadership of the South Florida Water Management District (SFWMD) has led to a renewed public optimism for major improvements in water quality management in south Florida. It is therefore timely for this review of the advantages and shortcomings of this “EAA (Everglades Agricultural Area) Reservoir Plan” to be widely disseminated in an international forum such as Ecological Engineering to encourage discussions among scientists and engineers.

Impact of land cover on groundwater quality in the Upper Floridan Aquifer in Florida, United States

Although agricultural lands are generally assumed to correlate negatively with groundwater quality, the intricate relationship between general land cover and contaminant concentrations present in an aquifer may vary substantially; contingent upon the land type, interacting factors, and scale considered. The Upper Floridan Aquifer (UFA) is a primary source of potable water supply for the state of Florida. The Suwannee River Water Management District (SRWMD), located in northcentral Florida, relies exclusively on the UFA for water supplies. Over much of the SRWMD in the UFA is unconfined, rendering it vulnerable to contamination from surface sources. This study analyses groundwater concentrations of Nitrate-Nitrogen (NO3–N) and Potassium (K) from shallow wells across the SRWMD for assessing the effect of different land covers on groundwater quality over time. Annual potentiometric surface maps were used to delineate semicircular recharge zones of 500 m, 1000 m, and 2000 m radii upstream of sampled well stations. Proportions of agriculture, forest, and urban lands were identified for each buffer zone using USDA Cropland Data Layer. Multivariate regression models were developed to infer relationships between land cover and NO3–N and K concentrations. Results show significant associations among land cover type, water table height, and groundwater quality parameters. Specifically, we find a large proportion of agricultural cover consistently associated with larger increases in groundwater pollutant loads relative to urban or forest cover across all models, after controlling for depth to water table. Our study suggests a need for widespread adoption of cost-effective agricultural best management practices (BMPs) that could help in securing regional water supply.

Handbook of Florida Water Regulation: Water Management Districts

This handbook is designed to provide an accurate, current, and authoritative summary of the principle Federal and Florida laws that directly or indirectly relate to agriculture. This handbook should provide a basic overview of the many rights and responsibilities that farmers and farmland owners have under both Federal and Florida laws as well as the appropriate contact information to obtain more detailed information. However, the reader should be aware that because the laws, administrative rulings, and court decisions on which this handbook is based are subject to constant revision, portions of this publication could become outdated at anytime. Several details of cited laws are also left out due to space limitations. This document is FE594, one of a series of the Food and Resource Economics Department, UF/IFAS Extension. Published December 2005.
 FE594/FE594: 2021 Handbook of Florida Water Regulation: Florida Water Management Districts (ufl.edu)

Profile and Economic Impacts of Agriculture and Natural Resource Industries in the Suwannee River Basin Counties of Florida

This paper presents an analysis of the regional economic impacts of agriculture and natural resource industries in the Suwannee River Water Management District in north-central Florida. The report provides a profile of agriculture and natural resource industries and an overview of their economic impacts for the Suwannee River Basin region. The report is based on data from the IMPLAN Pro database for Florida counties for 2002 and data from the 2002 Census of Agriculture.

Best Management Practices in the Everglades Agricultural Area: Controlling Particulate Phosphorus and Canal Sediments

The South Florida Water Management District has developed a BMP table that lists the BMP practices that have been designed to reduce particulate P and sediment loads in drainage waters from Everglades Agricultural Area (EAA) farms. The purpose of this document is to explain and discuss these particulate P and sediment control practices. These practices serve as important tools in efforts to improve water quality in the basin. This EDIS article is one in a series that attempts to explain in easily understandable terms the implementation methods and rationale behind the main P load reducing BMPs employed on EAA farms. This document is SL228, a fact sheet of the Soil and Water Science Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date August 2005.
 SL228/SS448: Best Management Practices in the Everglades Agricultural Area: Controlling Particulate Phosphorus and Canal Sediments (ufl.edu)

Best Management Practices in the Everglades Agricultural Area: Fertilizer Spill Prevention

Phosphorus fertilizer spill prevention is a Best Management Practice (BMP) approved by the South Florida Water Management District (SFWMD), one designed to reduce drainage P loads in the Everglades Agricultural Area (EAA). Spill prevention of P fertilizers is a BMP that is widely implemented by growers in the EAA. This BMP is easily implemented and can have an immediate impact on reducing off-farm P loads. This EDIS document is part of a series of publications that provide current implementation guidelines for commonly employed farm-level BMPs designed to reduce P loads from farms located within the EAA basin. This document is SL231, one of a series of the Department of Soil and Water Sciences, UF/IFAS Extension. Original publication date September 2005.
 SL231/SS450: Best Management Practices in the Everglades Agricultural Area: Fertilizer Spill Prevention (ufl.edu)

Florida’s recycled water footprint: a geospatial analysis of distribution (2009 and 2015)

Water shortages resulting from increased demand or reduced supply may be addressed, in part, by redirecting recycled water for irrigation, industrial reuse, groundwater recharge, and as effluent discharge returned to streams. Recycled water is an essential component of integrated water management and broader adoption of recycled water will increase water conservation in water-stressed coastal communities. This study examined spatial patterns of recycled water use in Florida in 2009 and 2015 to detect gaps in distribution, quantify temporal change, and identify potential areas for expansion. Databases of recycled water products and distribution centers for Florida in 2009 and 2015 were developed by combining the 2008 and 2012 Clean Water Needs Survey databases with Florida’s 2009 and 2015 Reuse Inventory databases, respectively. Florida increased recycled water production from 674.85 mgd in 2009 to 738.15 mgd in 2015, an increase of 63.30 mgd. The increase was primarily allocated to use in public access areas, groundwater recharge, and industrial reuse, all within the South Florida Water Management District (WMD). In particular, Miami was identified in 2009 as an area of opportunity for recycled water development, and by 2015 it had increased production and reduced the production gap. Overall, South Florida WMD had the largest increase in production of 44.38 mgd (69%), while Southwest Florida WMD decreased production of recycled water by 1.68 mgd, or 3%. Overall increase in use of recycled water may be related to higher demand due to increased population coupled with public programs and policy changes that promote recycled water use at both the municipal and individual level.

Restoring the Florida Everglades: Comments on the current reservoir plan for solving harmful algal blooms and restoring the Florida Everglades

This is an updated version of a review written by the author in April 2018 at the request of The Friends of the Everglades, an NGO based in Miami, Florida, on a plan developed primarily by the South Florida Water Management District (SFWMD) to mitigate coastal pollution that has resulted from discharges from Lake Okeechobee to the Gulf of Mexico and Atlantic coastline and eventually to “send the water south” to the Florida Everglades instead. This EAA Reservoir project was included by the U.S. Army Corps of Engineers in a 2018 U.S. Congressional bill that was approved. In May 2019, U.S. President Donald Trump pledged to spend $200 million to begin construction of this restoration, three times the amount requested by the state of Florida. While supported with enthusiasm by the Florida state legislature, the SFWMD, and some NGOs such as The Everglades Foundation, a change in leadership in the state of Florida after November 2018 elections and especially in the leadership of the South Florida Water Management District (SFWMD) has led to a renewed public optimism for major improvements in water quality management in south Florida. It is therefore timely for this review of the advantages and shortcomings of this “EAA (Everglades Agricultural Area) Reservoir Plan” to be widely disseminated in an international forum such as Ecological Engineering to encourage discussions among scientists and engineers.

Analysis and Extent of Santa Fe River Flooding in North Florida Attributed to Rainfall and Wind Damage Associated with Hurricane Irma

The Santa Fe River (SFR) is within the north Florida area of the regional Floridan aquifer system. The extent of recent flood damage in the SFR and tributaries in Bradford County has been attributed to rainfall and wind damage to trees associated with Hurricane Irma, September 2017. Implications of the determined cause of a disaster can include the allocation of disaster relief funds. Bradford County, Florida obtained approximately $2.5 million from the United States Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) for emergency flood abatement assistance and $255,875 from the Suwannee River Water Management District (SRWMD), combined with $13,750 in-kind match provided by the county, based on the attributed cause of that damage to rainfall and winds from Hurricane Irma. On January 2, 2018, Bradford County commissioners also approved grant applications to the SRWMD for $2.2 million for Alligator Creek Flood Mitigation and for $90,250 for Hampton Lake Canal to Santa Fe River Flood Mitigation, requiring in-kind matches from the county of $110,000 and $4750, respectively. Our study analyzed historical precipitation data for the SFR Basin and headwaters from 1895 through 2017 and recorded discharge and gage heights from the United States Geological Survey (USGS) to evaluate that presumed cause of flood damage in that basin and to provide a better understanding of historical relationships between precipitation, gage data and flooding in that basin. Recorded USGS peak gage height and Digital Elevation Models (DEMs) also were used to illustrate the lateral extent and relative depth of flooding associated with an extreme precipitation event in the lower SFR vicinity of O’Leno State Park. Finally, we evaluated the condition of the trees in the SFR Basin as an indicator of long-term anthropogenic groundwater alterations. Those data and analyses did not support the conclusion that Hurricane Irma was the only cause of the magnitude and extent of SFR flooding and tree damage in Bradford County and adjacent counties. Other contributors to stream flow in the SFR basin include heavy mineral mining wastewater discharges that have exceeded the maximum discharge volume of “40 million gallons a day” (MGD) under the National Pollutant Discharge Elimination System (NPDES) permit issued by the Florida Department of Environmental Protection (FDEP) to the Chemours Company TT LLC (Chemours, formerly DuPont) for Trail Ridge mining operations. The magnitude of those discharges suggests that those discharges and extensive Trail Ridge mining in Baker, Bradford, Clay, and Duval Counties contributed to the flooding and were a factor in the tree destruction in the SFR Basin.

Soil indicators of hydrologic health and resilience in cypress domes of West-Central Florida

Groundwater pumping in west-central Florida has caused water table declines that disrupt hydroperiods and negatively impact already threatened, geographically isolated freshwater wetlands in this region. Currently, aboveground biological indicators are used to determine the health status of wetlands impacted by groundwater withdrawals, however some soil properties, such as organic matter content, are partly a function of the duration of saturation and could be used as additional indicators. Therefore, this study evaluated soil organic carbon and related soil properties for comparison with the biological indicators of wetland health status. Soil samples were taken from the top 30 cm of the land surface (i.e., bulk density, soil water content, nitrogen content, and carbon and nitrogen isotopic composition) within pond cypress (Taxodium ascendens) domes previously categorized by the local water management district using wetland health classifications of “healthy”, “significantly changed”, or “severely changed”. Mean soil water content (w) was significantly higher in “healthy” wetlands as compared to “significantly changed” and “severely changed” sites, and “healthy” sites also tended to have lower bulk density and higher soil carbon and soil nitrogen content. This trend was most pronounced toward the center and lowest elevation of the wetland, presumably where soils remain saturated longest. Stable carbon isotope values (δ13C) of soil organic matter showed that “severely changed” sites exhibited more 13C-enriched values that arise from long term contributions of warm-season (C4) grasses, consistent with the observed upland grasses encroaching into the most impacted wetlands. Notably, soil characteristics may be crucial for determining the resilience of wetlands, as one sampled “healthy” site contained comparably less soil organic matter, reducing the water holding capacity and leaving it more vulnerable to water table declines. These results suggest that extensive annual saturation of soils is required to maintain the cypress dome ecological community structure and preserve wetland health and resilience. Frequent monitoring of soil water may prove a convenient proxy for soil water retention properties and ecosystem health of wetlands in similar settings.

Effects of short-duration hydraulic pulses on the treatment performance of a periphyton-based treatment wetland

The effect of high flows on total phosphorus (TP) removal in a 40-ha periphyton-based stormwater treatment area wetland (PSTA Cell) located in Stormwater Treatment Area (STA)-3/4 was evaluated by subjecting the PSTA Cell to three short-duration (3-day) hydraulic (high-inflow) pulses. The intent was to mimic hydraulic conditions that would be experienced during large storm events should the PSTA concept be implemented throughout the complex of treatment wetlands (STAs) operated by the South Florida Water Management District for Everglades restoration. The average inflow rate to the PSTA Cell during the pulses (1.3–2.0m3s−1) was approximately three to four times higher than under normal operation. The hydraulic loading rates (HLRs) during the pulses (28–43cmd−1) matched the peak 3-day HLRs observed in STA-3/4 during high inflows associated with storm runoff. Correspondingly, the phosphorus loading rates (PLRs) and hydraulic retention times (HRTs) during the pulses (2.3–6.3mgm−2d−1 and 1.4–1.8 days, respectively) were substantially higher and lower, respectively, compared to PLRs and HRTs in the PSTA Cell under normal operation. No reduction in TP removal performance was observed in the PSTA Cell during the pulses, and there was no indication that post-pulse outflow TP concentrations increased compared to pre-pulse levels in response to the pulse events. The short-term increase in hydraulic and TP loads during this study did not compromise the treatment efficacy of the PSTA Cell. If implementable in a cost-effective manner in the STAs, the PSTA concept could be part of a treatment strategy that achieves TP effluent limits mandated for these wetlands.

Water Use of Juvenile Live Oak (<i>Quercus virginiana</i>) Trees over Five Years in a Humid Climate

To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Quercus virginiana, commonly known as live oak trees, is endemic to Central Florida and among the most popular landscape trees for their gracefulness and spreading shade. To provide a basis for irrigation allocations both during production and in landscapes, daily actual evapotranspiration (ETA) in liters for three live oak trees was measured with weighing lysimeters over five years, beginning with seedlings and continuing until trees averaged 7.2 meters in height. Empirical models were derived to calculate ETA based on crown horizontal projected area (PCA) or trunk caliper (TCSA), adjusted daily by changes in evapotranspiration (ETO). Average ETA to produce these live oaks was 62,218 L cumulative over 5.5 years. Effectively transpiring leaf, tree water use volume divided by ETO, was closely related to PCA over five years with the slope of this relationship being equivalent to a Plant Factor of 0.93. The product of ETO and this Plant Factor can be used to estimate depth of live oak water demand in urban landscapes. Also, this Plant Factor can estimate water demand volume in nurseries and landscapes when combined with PCA, and similarly the slopes for TCSA can be used to estimate ETA water volume from measured trunk diameter.

Developing A Simple Water Use Model of Ilex x ‘Nellie R. Stevens’ from Liners to Four Meter Tall Trees

To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Ilex spp. (holly) trees are endemic to Central Florida and among the most popular landscape trees for their hardness, bright colors and go-anywhere size. To provide a basis for irrigation allocations both during production and in landscapes, daily actual evapotranspiration (ETA) for three holly trees were measured with weighing lysimeters over 5.75 years, beginning with rooted cuttings and continuing until trees averaged 4.3 meters in height. Empirical models were derived to calculate ETA based on crown horizontal projected area or trunk caliper, adjusted daily by changes in evapotranspiration (ETo). Average ETA to produce these hollies was 20 432 L cumulative over 5.75 years.

Development of a new model tool for evaluating groundwater resources within the Floridan Aquifer System in Southern Florida, USA

The US Army Corps of Engineers (USACE) and the South Florida Water Management District (SFWMD) are partners in an ambitious plan to restore water flows throughout the Everglades ecosystem. An important component of the restoration plan involves storing excess stormwater deep underground in the Floridan Aquifer System using aquifer, storage and recovery (ASR) wells. In order to determine the optimal ASR system and to assess environmental impacts, USACE spent over 11 years and significant resources to develop a three-dimensional groundwater model of the Floridan Aquifer System covering a large portion of the Florida peninsula. This SEAWAT model is capable of evaluating changes in aquifer pressures and density-dependent flows in the entire study area. The model has been used to evaluate the Everglades ASR system already but could also be used by water managers for other important water resources studies in Florida including water supply estimates and adaptation to climate change. As part of an effort to make the model more readily available for other important studies, this study documents and summarizes the overall development of the SEAWAT model including a discussion regarding the intensive calibration and validation efforts undertaken during model development. The paper then demonstrates the use of the model using Everglades ASR project alternatives. Lastly, the paper outlines potential future uses of the model along with its overall limitations. Supplementary online resources are also included that provide researchers with further detail regarding the model development effort beyond the scope of this summary article as well as model development databases.

When Local Government Misbehaves

his Article addresses one of the lingering questions following the Supreme Court’s decision in Koontz v. St. Johns River Water Management District. In that land use case, the Court held that proposed local government monetary exactions from property owners to permit land development were subject to the same heightened scrutiny test as imposed physical exactions. The Court left unanswered the question of how broadly this heightened scrutiny should be applied to other monetary obligations imposed by the government. The Article argues that “in-lieu” exactions that are individually assessed as part of the permitting process should be treated differently than the impact fees that are developed through the legislative process and are applied equally to all developers without regard to a specific project. Accordingly, Koontz’s application should be limited to “the special context of land-use exactions” during a permitting process rather than be extended to all regulatory monetary obligations. The Article begins by identifying the various levels of scrutiny applied to land use decisions and shows how these levels are designed to prevent the abuse of power, particularly when actions are exercised at the individualized level. It concludes by suggesting that exactions that result in a permanent physical occupation of real property should be subject to heightened scrutiny. However, only administrative, individualized, monetary exactions, designed to replace a physical exaction, such as the kind involved in Koontz, should be subject to heightened scrutiny to control the potential for abuse. Legislatively determined monetary conditions such as impact fees, but not taxes, should be subject to review under state statutory or judicial standards, which range from a rational basis test to more stringent tests, such as the dual rational nexus test or the Nollan/Dolan test. In the absence of a state standard of review, legislatively enacted impact fees challenged in federal court should be analyzed under the deferential rational basis test for land use regulation.

These Models Need Enterprise Data Management!

After 28 years of public service, the Information Technology Bureau Chief for the Southwest Florida Water Management District (SWFWMD), Dr. Steven Dicks, was still passionate about serving the public. By first focusing on the needs of people in the District, Dr. Dicks was able to objectively observe the many aspects of operations for which he was responsible. His observations led him to believe that the use of technology within his organization wasn’t as effective and efficient as he knew it could be. The SWFWMD managed the water resources of 16 Florida counties in an area that was close to 10,000 square miles, with 4.7 million inhabitants. To effectively manage water resources, the organization needed to understand current water needs, prepare for future needs, and protect and preserve water resources within its boundaries. A significant part of managing water resources involved the production and utilization of scientific computer models that help track, predict, and control a plethora of water related challenges. At the SWFWMD, individuals used desktop computers to run most of the scientific models. Given the limited computing capacity of the average desktop computer, running a model was beginning to require too much time; and simple interruptions, such as a system reboot, could jeopardize the ability to complete long model runs. Therefore, the resulting data used and produced was often very ineffectively managed. Dr. Dicks began to wonder about the current system of producing and managing scientific models, and how the systems might be improved. He evaluated options. He thought upgrading individual desktops could help, but only in the short term because as the data sets and demand for processing power continued to grow, the desktop might always be a step behind. Installing powerful servers to house the data sets and run the models would be a significant improvement, but the cost to acquire and maintain the new system might challenge the budget. A cloud-based solution utilizing an “infrastructure as a service” approach, was a third option, but current system infrastructure compatibility, security, and access needed to be carefully evaluated. Dr. Dicks believed that data management was just as important as the processing power of an upgrade, and that ultimately the technology that allowed for the most effective EDM system needed to be identified and implemented to best serve the needs of the District into the future.

Experimental Demonstration of a New Extension Plate Scour Countermeasure Downstream of Stilling Basins

AbstractLaboratory experiments were conducted in order to investigate the effectiveness of a new scour countermeasure consisting of a horizontal extension plate (EP) downstream of a gated spillway-stilling basin structure. These experiments were performed on a 1:30 scale model of one of the South Florida Water Management District (SFWMD) gated spillway structures, the S65E gated spillway, because it has experienced worrisome downstream scour. Currently, riprap is the only scour countermeasure documented for these structures. EPs of various lengths were installed downstream of the stilling basin, and the equilibrium scour was measured. It was found that a plate length of approximately 1.88 times the exiting flow depth was the shortest length that resulted in significant scour reduction and downstream scour translation. Measured flow patterns reveal that the EP altered the flow patterns by transferring the plunging flow downstream and eliminating the near-bed reattachment and surface recirculation, possibly...

Using SPOT and Aerial False-Color Infrared (fCIR) Imagery to Verify Floodplain Model Results in West Central Florida

Tropical Storm Debby brought severe flooding to portions of southwestern Florida during the summer of 2012. Remotely-sensed images were collected to document the flooding and test the results of Hydrologic and Hydraulic (H & H) storm water models constructed by the Southwest Florida Water Management District (SWFWMD). One image, a satellite, multi-band SPOT image was provided to the SWFWMD by the Federal Emergency Management Agency (FEMA). This image was collected within 48 h of the storm event. The SWFWMD also contracted for a very high resolution (60 cm Ground Sample Distance (GSD)) fCIR image to be captured for selected watersheds in Citrus, Hernando and Pasco counties, the areas most impacted by the flooding. Modeled floodplain results were compared to remotely-sensed images that were georeferenced and analyzed using remote sensing techniques. The higher resolution fCIR images more clearly identified flooding for better comparison with modeled results. Although the fCIR images, which were collected three to four days after the storm event, under predicted the overall extent of the modeled floodplain, as the images could not confirm the presence of flooding in areas obscured by dense vegetation, they did consistently confirm both the location and shape of flooding simulated by the model. By using image analysis methods on the Near-Infrared (NIR) band of the fCIR image in conjunction with the Digital Elevation Model (DEM), however, it was possible to identify the extent of flooding in those obscured areas. Field surveys of high water elevations indicated that many locations had receded within hours of the storm event, limiting the ability of the fCIR image from capturing peak flood level in all areas. Overall, these remotely-sensed images provided a good validation of predicted flood levels for a design storm of the magnitude of Tropical Storm Debby.

Evapotranspiration and Above Ground Biomass of <i>Acer rubrum</i> from Liners to 8 m Tall Trees

To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Acer rubrum L. (red maple) trees are endemic to Central Florida and native to the eastern portion of the United States. Urban and suburban expansion has increased use of A. rubrum in landscape plantings and their production in nurseries. In Florida A. rubrum is planted around stormwater retention areas, but also in urban landscapes. To provide a basis for irrigation allocations both during production and in landscapes, daily actual evapotranspiration (ETA) for three red maple trees were measured with weighing lysimeters, beginning with rooted cuttings and continuing until trees averaged 8 m in height. Empirical models were derived to calculate ETA based on crown horizontal projected area or trunk caliper, adjusted daily by changes in reference evapotranspiration (ETo). Water use efficiency, based on carbon sequestered in above ground wood mass, was calculated at the end of five growing seasons. Average ETA to produce these maples was 29,107 L over 4.75 years, with an average water use efficiency of 1 kg dry mass of wood per 709 L of water lost by transpiration.

Takings and Mitigation

When land developers approach a State Department of Transportation (“State DOT”) for permission to build access to a State highway, the State DOT may attempt to mitigate the development’s impact to the highway system by exacting concessions from the developers. For example, State DOTs often require the donation of a portion of the developer’s real property for an acceleration/deceleration lane near the entrance of the development, for highway widening to support additional traffic generated by the development, or for other improvements. Likewise, other permitting agencies, such as local governments and environmental and natural resource agencies, may be charged with exacting other concessions to mitigate the development’s impact to the environment. Increasingly, permitting agencies including State DOTs attempt to exact offsite improvements (e.g., require the developer to fund or construct improvements to the State highway system) rather than on-site exactions such as dedications of a portion of the developer’s real property. In 2013, in Koontz v. St. Johns River Water Management District, the U.S. Supreme Court held that heightened judicial scrutiny (known as the “essential nexus” test) applies in cases of offsite exactions. The essential nexus test, articulated in the Court’s earlier Nollan and Dolan opinions, was previously understood to apply to onsite exactions. The essential nexus test requires the permit condition to have a close relationship or “nexus” to a legitimate governmental interest involving the proposed development, and for the burden on the developer to be roughly proportional to the anticipated adverse impact of the development on the public. A permit condition that fails to satisfy the essential nexus test is an unconstitutional taking. The purpose of this report is to provide updated legal research regarding the legal standard for exactions, including the impact of the 2013 Koontz decision on the ability of State DOTs and other permitting agencies to advance public policy goals (e.g., traffic flow management, public safety, and environmental mitigation) in the land use permitting and project development processes.