Protecting Springs
The following files are located on the Foundation server and may be accessed directly using Adobe Reader,
simply select and click the appropriate file.
- Ground water flows – a case study to examine tributary flows
within the aquifer to see where pollutant sources may enter Spring outflows.
- Research Paper: Naturecoast Water Systems, June, 2011.
- Extracts from Florida Geological Survey Bulletin 69 by Rick Copeland et al 2010.
- Research Paper re. FPSC Annual Review of Docket NO. 080148-EI. (Environmental impact of power generation).
- Protecting Florida's Springs – a document
published in 2002 as a guide to Land Use Strategies and Best Management Practices for Counties and
Municipalities.
- A Guidebook of Springs Protection – a document
published in 2008 with fewer graphics than that in 2002 but having a valuable Legal Appendix.
Selected pages from these documents may be accessed using links embedded within the following text.
Aquifer Groundwater Flows
A proportion of surface water is continually evaporated and transpired back into the atmosphere, part runs
off as streams or collects in basins as ponds or lakes, part permeates under ground to enter voids in rocks to
flow downhill eventually to the sea. Water contained in the voids in the rocks is subsurface water and that
which completely saturates the rock is groundwater. If the top surface of the groundwater is free to fluctuate
upwards and downwards the water is under water–table conditions. If the groundwater surface is overlain
by a formation that contains few voids, or poorly connected voids or small enough voids to restrict the flow
of water, the water is confined and under artesian conditions. (Dr. Robert O. Vernon writing in his 1951
report published as Florida Geological Survey – Bulletin 33)
In that report, (on page 43) he also writes, "Limestone is as a rule jointed vertically and bedded
horizontally and openings along these joints (vertical)and beds (horizontal) provide easy avenues of travel
for water. The ultimate source of all Florida's ground water is from the rain and precipitates from the
atmosphere. As the rain water falls through the air it becomes charged with carbon dioxide gas that combines
with water to form carbonic acid. On the ground humic acid from rotting vegetation is added. These are the
common solvents of limestone. ... As it moves through pores and open spaces in the limestone it acts as a slow
solvent to increase the size of the openings and to connect them to form a continuous system of channels. As
these channels are expanded by solution, cave systems are developed horizontally and one system may lie over
another and may be connected by vertical tubes and rooms."
Dr Vernon emphasizes (on page 240); "since all fresh water in Citrus county is derived directly from
atmospheric precipitation falling locally and on adjacent counties, conservation of groundwater resources
requires that water consumed does not exceed that which is readily available from streams, lakes and wells and
that this usage be small enough to maintain normal storage of waters on the surface and in the ground.
Otherwise, lake levels lower, and well and stream flows decrease".
Artesian water flows
Also referred to as Piezometric or Potentiometric flows, Artesian waters in a confined or partially
confined aquifer flow from place to place underground according to the differences in artesian pressure from
areas of higher pressure to those of lower pressure. (Analogous to water flowing "down hill".)
Dr Vernon in the Bulletin 33, describes water added to the aquifer from rainfall and leaving it as it is
pumped out or runs down to the sea. Artesian aquifer waters of Citrus county are derived from rain falling on
the county and others as far away as Baker and Polk, some 100 or 75 miles distant. Travel times over such
distances are long indeed.
In (Page 4) Bulletin 33, Figure 40, Dr Vernon depicts artesian
water flows of Florida. Constructed by measuring water levels in wells penetrating into the aquifer, referring
the measurements to sea level and locating the wells on a map of Florida to illustrate the imaginary surface
formed by joining points of equal pressure with smooth lines called contours. The direction of artesian flow
is perpendicular to the contours, from areas where the artesian surface pressure is higher to areas of lower
pressure. Areas where water is being added to the aquifer are referred to as recharge areas, and relatively
low contours are referred to as discharge areas where water leaves the aquifer by leakage, pumping, springs or
wells. The FDEP database records the Kings Bay springs (page 7) recharge
basin resulting from these flow patterns.
Fracture conduit water flows
Within the pattern of artesian water flows in an aquifer system, geologic structures influence the
direction and pace of flow. Dr Vernon is joined by Dr Glen L. Faulkner, writing twenty two years after Dr
Vernon in the U.S. GEOLOGICAL SURVEY Resources Investigations Report, I–73, in which he relates that he
and others have observed that most caverns and solution channels in the limestone are oriented along near–vertical
fractures having trends of fracture systems mapped at the surface. The logical inference is that water moving
through the aquifer under artesian influences tends to follow the line of least resistance or greatest
permeability, which in this case is along the fractures. In general, the greatest solution of limestone at
shallow depths below the water table takes place where the greatest amount of water moves through. Thus
cavities are developed as the walls of fractures are dissolved away by recently recharged ground water with a
high carbon dioxide (CO2) content.
Thus two factors contribute to the routes taken by groundwater flows. First, are the general patterns of
artesian flows, and second, the concentration of such flows and modification to their route when they join
flowing ground waters in fracture conduits. An essential difference between the two is that patterns of
artesian flow may vary with season and periods of drought or plenty, as aquifer head levels change
sufficiently to open or close available channels through the rock. On the other hand, fracture conduits which
have existed millions of years do not change their position. They only enlarge with the passage of time so
long as acid charged waters flow into them, or accumulate sediments or material particles over time which
affect the permeability and rates of flow in the conduits. Rates of conduit flow may change as material is
added to the conduit from waters flowing into it along the path of the conduit.
Karst Terrain
The carbonate rock formations encountered by Dr Vernon and Dr Faulkner exhibit characteristic karst surface
features. These include the surface water as streams, ponds, and lakeland areas, wetlands, sinkholes formed by
cave collapse near the surface, solution pipes created by upward artesian pressures to form springs or seeps at
the ground or sub aquatic surface, and cave systems – both those which are dry and containing water.
Click here to see also the report, The
Citrus County Aquifer Vulnerability Assessment
Porosity and Permeability
Porosity is the percentage ratio of the volume of void spaces to the total
volume of material in a given space. It represents the relative storage capacity of that space. Permeability is a measure of the ease with which fluids will flow though such a space where the voids are interconnected to
allow fluid to flow.
Dr Vernon explained the formation of holes in limestone rock formations, which have the capacity to store
groundwater and, as the holes (both small and large) are interconnected, to facilitate artesian flows. Flow
rates are conditioned by material occupying the rock voids together with the water, and thus flow rate is a
function of porosity and permeability both for groundwater artesian flows and flows in fracture conduits.
Rock fractures significantly affect rates and direction of groundwater flows, as Dr Faulkner has emphasized.
Fractures may be completely void, both small and extremely large spaces, and have accumulations of material in
them. Fractures may collect a variety of material into the fracture space as artesian flows join along the
whole length of the fracture, or a number of associated fracture paths. Rates of flow in fracture conduits
vary according to porosity and permeability. The composition of the material accompanying water in the rock or
fracture voids affect rate of flow through the rock or fracture space. The shapes, sizes, and degree to which
granular materials are packed together affect both porosity and permeability properties in rock formations and
fractures. In addition, of course, the intrinsic fluid viscosity and pressure also influence the rates of flow.
Ground/Surface water balance
Dr Vernon discussed the relationship between groundwater under artesian conditions (Floridan
aquifer) and water under water table conditions (surficial aquifer). He and Dr Faulkner also discussed how
waters fed from underground flows appear at the surface. Surface waters become streams, rivers, lakes and
wetlands which have flow paths conditioned by topography rather than the artesian pressures and fracture
conduits. Surface waters are exposed to interaction with the atmosphere and saltwater tides. Lake evaporation
rates locally in Citrus County average some four feet per year into the atmosphere. In addition, trees and
plants transpire water to the atmosphere at modest rates.
A Climatic Water Budget can be derived to illustrate the balance at the surface represented by:
PRECIPTATION (from the atmosphere) EQUALS (EVAPORATION + TRANSPIRATION – WATER SHORTAGE (historical)) +
SURPLUS(moisture) + STORAGE_DELTA (soil water change). Such budget information is used to indicate water
deficiency, water surplus, soil water recharge, and soil moisture utilization. Utilization is a measure of the
amount of water percolating into the ground minus any amount taken up by plants and used or transpired, which
recharges the aquifer ground water supply.
This water balance is a vital component of environmental health, impacting local and global climate and
weather, agriculture and livestock, marine and fresh water fisheries and recreational quality of life. It is
radically influenced by man's creation of impervious areas for roads, parking, buildings, the cutting of
forests and building heat generating power plants, which diminish waters fed back into the atmosphere by up to
one tenth, reduce ground infiltration by up to three tenths and increase run off by at least four times –
gathering a rich supply of pollutants on its way before eventual release into aquifer waters.
Photo Lineaments
It makes sense to understand where the waters travel in underground flow paths, before they are discharged
(together with their collected pollutants) from springs and seeps into surface waters, or are tapped by wells
for domestic water supply. Various methods are employed to detect and record the surface indications of
happenings underground, ranging from aerial survey analysis, to dye tracing and analytical water sampling to
reveal common sources of water.
Activities underground show on the surface. Over time linear depressions in the ground surface may form.
Changes in color and density of foliage may be observed in linear pattern and even soil changes may be seen.
In the past aerial surveys using black and white, color and infra–red stereo pair photography have been
made. More recently laser and radar techniques have been employed.
A product of aerial surveying is the plotting and analysis of photo lineaments which represent "aligned
solution depressions, surface ponds, vegetation, and variations in soil tone. Doline (sinkhole) development
can be expected to follow orientation of photolinears, as these represent areas of higher permeability and
porosity".(Trainer and Ellison, 1967, Parizek, 1975). The Foundation conducted research to seek out such
photo lineament data after learning that springshed patterns in a project scheduled in a 1966 – 2004
SWIM Technical Summary report could not be completed for lack of funds.
A photograph of a mylar sheet of lineaments for the whole of Florida was obtained, from the Remote Sensing
Section, State Topographic Office, Florida Department of Transportation showing lineaments for the whole of
Florida derived from aerial surveys conducted in 1972 and 1973. Several weeks later a 30 x 30 inches (approx)
of the actual mylar was obtained from a state archive complete with a set of registration marks. Later, a
mosaic of sixteen (16) multispectral images taken by the NASA/GE Earth Resources Technology Satellite from an
altitude of 570 miles, taken between Oct'.72 and Apr.'73, was also obtained bearing identical
registration marks to those on the mylar.
Both the mylar and the mosaic were scanned and aligned with each other in computer memory. A procedure was
devised to compute latitude and longitude of the registration points and lineaments for a selected area. A
region encompassing Citrus county and part of Levy county was prepared and checked for accuracy. The lineament
latitude and longitude data were entered to a database of Google Earth. The Florida Department of
Environmental Protection database of sinkholes was incorporated into the same Google Earth database. Lastly,
Latitude and longitude data of spring vents, for Kings Bay and adjacent areas were then added supplied by the
Southwest Florida Water Management District, derived from an Inventory of Spring Vents published in May, 2009.
Groundtruthing to a remarkable level of consistency was observed with sink hole and spring vent data,
together with GPS data of two caves in the Withlacoochee State Forest coincident with lineament traces.
Selecting lineaments having multiple sinkholes and spring vents co–located upon them strongly
suggested the presence of active fracture set conduits arranged as (page 9) two
underground tributaries serving Crystal River/Kings Bay, which deserve the most stringent application of
land use strategies and best management practices to contain the risks of (page 11) degrading
water quality of that Outstanding Florida Water.
This pattern of lineaments indicates how the two water sources discharging into the south–west and
north–east portions of the bay could help explain the different levels of specific conductance readings
(saltiness) which are lowest from the group of vents in the
north–east sector of Kings Bay, and highest from those vents to the south–west sector of the bay.
Graduating readings for vents in between, together with the USGS Open File Report 96–230, (1996),
Hammett, K.M., et al, which observes that surface waters do not intermingle between the north–east and
south–west portions of the bay, indicates underground mixing taking place within the confluence
underground of the tributary flows.
Land Use Strategies and Best Management Practices
Florida's springs are not only a unique and beautiful resource, but also serve the important function
providing a "window" into a valuable resource – the ground water in the Floridan aquifer
system. Over 90% of the State's drinking water comes from this source. Use of the waters of Crystal River/Kings
Bay are a valuable resource to the local economy protected by law and not to be degraded.
Protecting Florida's springs means ensuring that water entering the aquifer is free from pollutants. It
also means ensuring that adequate levels of water can recharge the aquifer. Because our drinking water comes
from the same aquifer that supplies water to the springs, the quality and quantity of water in the springs
indicates the quality and quantity of our drinking water. There is a significant body of research about the
aquifer and Florida's springs. The Implementation Guidebook
contains an explanation of the scientific basis for protecting springs and provides an overview of this
research as a basis for amending local comprehensive plans to ensure protection of springs. Understanding the
basis for protection leads to identifying best management practices that ensure protection.
Best management practices are actions that local governments can take to eliminate or reduce adverse
impacts upon the aquifer and springs. They include good policies for the local comprehensive plan. The
policies in the Implementation Guidebook recommend limiting intensive land uses as well as those land uses
associated with potential negative impacts to the aquifer. The policies also suggest standards for the
location and design of development and management of stormwater and wastewater. Best management practices are
recommended in the guidebook as regulatory tools to implement the provisions of the comprehensive plan. The
regulatory tools provide the details for the design of development projects, limitations on impervious
surfaces, protection of open space, the design and management of stormwater facilities, and the design and
management of wastewater. While the document presents best practices, which may be used by the public and
private sectors, it does not constitute rule or regulation and is advisory only.
As a matter of municipal policy, the tributaries to Crystal River should each be protected by an Overlay
Protection District requiring any development to be permitted only within the framework of a certified
Geotechnical Study conducted at the expense of the developer and accepted by the municipality. Within a
delineated primary protection zone permitted land uses should be confined to preservation, conservation,
recreation and open space, long crop rotation silviculture or low intensity unimproved range land. In the
delineated secondary protection zone moderate densities and intensities prevail appropriate to silviculture,
rangeland, and low density rural residential. High density activities as to big box stores and office blocks
with extensive carparking are forbidden in primary and secondary protection zones, eliminating large
impervious areas, mining, industry and commerce activity.
Legal framework
Notwithstanding that "Waters" are defined whether or not flowing underground through pores or
conduits, (Sections 62–520,200(21) FAC.), the following interpretations have been given by FDEP by (page 12) e–mail
exchange with the Foundation and aver that state law does not recognize underground tributaries (Only
federal law does that under the (page 12) Clean Water Act, 1972).
- Classification of a surface water as an Outstanding Florida Water does not extend that classification to
adjacent groundwater. Florida law treats surface water and groundwater as two separate things even when
groundwater flows directly into a surface water.
- Wetlands whose only connection to other state waters is via groundwater flow are considered "isolated",
as state law does not recognize such connections.
The Appendix A2 to the Guidebook has an extensive legal exposition on (page 117) LEGAL
FOUNDATION FOR IMPLEMENTATION OF SPRINGS PROTECTION.
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