The Floridan Aquifer, Springs, and the Balance Between Humans

The Floridan Aquifer,
Springs, and the
Balance Between
Humans and Nature
Rock Springs,
Orange County
Robert L. Knight, Ph.D.
Howard T. Odum Florida
Springs Institute
American Planning Association,
September 4, 2014
Can Industry, Agriculture and Growth Co-Exist with
Healthy Springs?
Regional Extent of the Floridan Aquifer System (100,000 sq. mi.)
http://fl.water.usgs.gov/FASWAM/
North Florida: “Land of a Thousand
Springs”
Wakulla
Ichetucknee
The Floridan Aquifer
System supplies fresh
water to Florida’s 1,000+
artesian springs – the
largest springs
concentration in the world!
Silver
Wekiwa
Weeki
Wachee
Groundwater is Florida’s Most
Valuable Natural Resource
 Groundwater is the sole water supply for
North Florida springs and river baseflows
Groundwater is Florida’s Most
Valuable Natural Resource
 Groundwater is the sole water supply for
North Florida springs and river baseflows
 The aquifer is an underground reservoir that
provides water storage during droughts
Groundwater is Florida’s Most
Valuable Natural Resource
 Groundwater is the sole water supply for
North Florida springs and river baseflows
 The aquifer is an underground reservoir that
provides water storage during droughts
 The aquifer is a regional distribution system
that makes potable water widely available
Groundwater is Florida’s Most
Valuable Natural Resource
 Groundwater is the sole water supply for
North Florida springs and river baseflows
 The aquifer is an underground reservoir that
provides water storage during droughts
 The aquifer is a regional distribution system
that makes potable water widely available
 Groundwater is naturally filtered and requires
minimal treatment costs
Springs Problem – Part I
Groundwater resources are
stressed:
– Groundwater consumption is
very high
– Groundwater levels have
fallen
– Spring flows are lower
Agriculture
Residential
Golf Courses
Florida’s Hydrologic Cycle
Recharge = 6% of Rainfall
Precipitation
Evaporation
Groundwater
Recharge
Florida’s Hydrologic Cycle
Pumping = 30% of Recharge
Precipitation
Evaporation
Groundwater
Recharge
Groundwater
Pumping
The Floridan Aquifer is Over-Permitted
Existing Groundwater
Consumptive Use
Permits:
– Total permits –
28,630
– Estimated 2010
pumping – 2,622
MGD = 30% of
recharge
– Total allocated
groundwater use –
4,630 MGD = 50%
of entire aquifer
recharge!
Water Management District data
North Florida Groundwater Pumping (2010)
Pumping is
concentrated in
urban and industrial
population centers:
•Polk – 251 MGD
2,622
MGD
•Orange – 249 MGD
•Duval – 155 MGD
•Hillsborough – 151
MGD
•Pasco – 94 MGD
•Lake, Volusia, Osceola
> 90 MGD each
USGS Data
Floridan Aquifer Levels are Falling
Decline in the
water levels of the
Floridan Aquifer
(predevelopment to
2000):
•Northeast FL: 20 to
60 ft
•Marion County: 4 to
20 ft
Silver Springs
Groundwater
Basin
Rainbow Springs
Groundwater Basin
•Orlando area: 10 to
34 ft
•Southwest FL: 20 to
>60 ft
Florida Geological Survey
Spring Flows are Declining Statewide
1200
Silver (cfs)
Rainbow (cfs)
1000
Silver Springs
Discharge (cfs)
800
600
Rainbow Springs
400
200
Percentile
0
10
25
50
75
90
100
0
1940
Silver
383
541
630
734
843
932
1,108
Discharge (cfs)
Rainbow Silver+Rainbow
500
883
572
1,132
618
1,254
687
1,425
768
1,614
868
1,775
911
1,980
Estimated Silver Springs Flow
Decline is 160 MGD (32%)
1950
1970
1960
1980
1990
2000
2010
2020
Springs Problem – Part 2
• GW nitrate nitrogen levels are
increasing:
– Nitrate contamination is widespread in the Floridan Aquifer
– Springs are sensitive to elevated
nitrate
Nitrogen Sources
Agricultural and
Urban Development
are Resulting in
Elevated Nitrate
Nitrogen
Concentrations
throughout North
and Central Florida
(and Many Other
Areas of the U.S.)
Nitrate-Nitrogen
•Nitrate is a plantgrowth nutrient
•Stimulates growth of
“weedy” algal species
that can out-compete
more efficient plants
that grow at lower
nitrogen availability
Wakulla Spring – 1960s
Wakulla Spring - 2013
In Many Springs the Effects of Flow
Reductions and Pollution Include:
•
•
•
•
•
•
Increasing algae
Reduced native plants
Impaired water quality
Lower food chain support
Less wildlife
Declining aesthetics
These are BIG Problems for Florida!
• More pumping = lower
aquifer levels
• Lower aquifer levels =
more sinkholes, salt
water intrusion, and
dry lakes, springs,
rivers, and wells
• More pumping =
increased fertilizer and
groundwater nitrate
• More nitrate =
unhealthy aquifer,
springs, rivers, and
estuaries
Sinkhole in Columbia County
Our Groundwater is no Longer Clean
nor Abundant
• Groundwater
pumping has
increased to more
than 30% of average
historic spring flow
• Groundwater nitrate
has increased by
about 2,000%
• Spring flows are
depleted, polluted,
and getting worse
Photo by Bruce Mozert
Will Our Economy Prosper Without
Plentiful and Clean Groundwater?
Smarter Water Resource Management
•Current urban,
agricultural, and
industrial practices
are intensive users
and polluters of
groundwater
•Groundwater is too
precious to use when
rainfall and surface
water supplies will
suffice
What is the Sustainable Water Use?
• WMDs have defined
significant harm to springs at
about 10% average flow
reduction
• For the entire Floridan
Aquifer System this is equal
to about 1.4 BGD
• This analysis indicates the
need to reduce allocated
groundwater pumping in
north Florida and south
Georgia by about 70%
What is the Sustainable Nitrogen Load?
• Existing average nitrate
nitrogen concentration in
Florida springs is greater than
1.0 mg/L
• FDEP has defined 0.35 mg/L
nitrate N as a maximum safe
concentration
• Meeting this goal will require
reducing total nitrogen loads
by about 65%
• “Advanced” BMPs will be
needed to achieve these goals
Sustainable Water Management
A greater reliance needs to be placed on
surface water storage and utilization to reduce
groundwater uses and to recharge the aquifer
with clean water
Green Cay
Groundwater
Recharge
Wetland, Palm
Beach Co.
Clean and Abundant Water Will Likely be the Most
Important Environmental Issue Affecting Your Future
Healthy Springs = Healthy Economy
Summary
• Florida is blessed by high
rainfall and large underground
aquifers
John Moran photo
Summary
• Florida is blessed by high
rainfall and large underground
aquifers
• Human activities are depleting
and polluting Florida’s
groundwater aquifers
John Moran photo
Summary
• Florida is blessed by high
rainfall and large underground
aquifers
• Human activities are depleting
and polluting Florida’s
groundwater aquifers
• Many springs have declining
flows and increasing nuisance
algae populations
John Moran photo
Summary
• Florida is blessed by high
rainfall and large underground
aquifers
• Human activities are depleting
and polluting Florida’s
groundwater aquifers
• Many springs have declining
flows and increasing nuisance
algae populations
• These problems can be
overcome by accepting our
responsibility to be better
stewards of the land and water
John Moran photo
Summary
• Florida is blessed by high
rainfall and large underground
aquifers
• Human activities are depleting
and polluting Florida’s
groundwater aquifers
• Many springs have declining
flows and increasing nuisance
algae populations
• These problems can be
overcome by accepting our
responsibility to be better
stewards of the land and water
• We need to balance our
groundwater “checkbook” to
provide for a prosperous future
and Springs Eternal!
John Moran photo
Citizens are Demanding Better Protection for
the Floridan Aquifer and Springs!