1. 2015 UN – Water Annual International Zaragoza Conference
Water and Sustainable Development: From Vision to Action
15–17 January 2015
Emilio CUSTODIO, Dr.I.I., Real Acad. Ciencias
Department of Geo–Engineering / Groundwater Hydrology Group
Technical University of Catalonia (UPC), Barcelona
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Contents
Intensive groundwater development
Intensive groundwater development in Spain
The MASE Project
Groundwater mining in Spain: the South–east and the
Canaries
Environmental aspects and consequences
Prospective
Intensive use of aquifers and groundwater mining in Spain
Proyecto MASE
AQUALOGY–UPC
Side event: The influence of recent technological advances in Spanish
and global water policy
14–01–2014 Pre–Conference Side Events and Technical Visits

2. Effects groundwater development
Time τ to equilibrium
L = system size
T = transmissivity
S = storage coefficient
α = coefficient (0,25 to 1)
τ : months (small aquifers, nearby recharge)
: years (middle aquifers)
: very large (big aquifers)
If B ≥ R  groundwater mining
B = pumpage
R = recharge
In semi–arid zones:
it may be difficult toknow if B <=> R
τ α≈
2
L S
T
Simple aquifer in a depression with
only diffusse recharge
NATURAL
CONDITION
DISTURBED
CONDITION
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3. Some approximate definitions applied to groundwater
Intensive development: a significant fraction of recharge is abstracted
important changes in the aquifer flow system
in its relation with other water bodies
drawdown may be large and increasing along time
results are quantifiable but do not imply a qualification
Overexploitation: Negative effects observed on groundwater quantity and quality
Subjective appreciation
It does not consider if the effects are due to hydrynamics
In Spain it is a legal term
Its use should be discouraged (although is colloquially used)
Resevable resources: ~ total net recharge
Circumstances should be clearly defined
Exploitable resources: Those that can be abstracted with bearable consequences
Depends on what is bearable
economically, environmental, socially and politically
This is not a true technical result
Groundwater mining ≡ sustained use of groundwater reserves
It implies: abstraction > recharge  steady state not possible
It is a long–term evaluation
If aquifer abstraction ceases  recovery needs > 50 years
A large part of freshwater storage is changed into saline water2015–Zaragoza UN–32015–Zaragoza UN–3

4. Consequences of groundwater intensive use and mining
Positive / benefits Negative / costs
Water supply
Economic and social development
Employment
Help to settle population
Land drainage (if enviromentaly aceptable)
Growing groundwater costs (energy, replacement, …)
Discharge reduction (water not available down flow)
Water quality loss (not always) and its effects
Loss of abstraction capacity
Land subsidence / collapse (in some cases)
Decrease of ecological services and environmental damage
Pollution enhancement (in some cases)
The consequences due to groundwater
may be indistinguishable during the first development stages
intensive use
mining
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5. Intensive groundwater use in the World
a
b
c
d
Average recharge mm/yr Total abstraction mm/yr
Depletion of groundwater reserves, mostly dynamic effects
Year 2000
Values in mm/year
Green points concentration in Spain
Wada et al., 2010
Detail
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6. Spectacular development of groundwater in Spain
Groundwaterabstraction(hm3
/year)
Groundwaterabstractionkm3
/year
Spain ≈ France
Margat & Van der Gunn, 2013
Groundwater abstraction in Spain
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7. Non–renewable groundwater exploitation in selected countries, around year 2000.
Values in hm3
/year
Country
Groundwater /
total of water Total, A Non–renewable, B B/A
Argeria
Saudí Arabia
Bahrain
Egypt
UAE
Lybia
Oman
Qatar
Tunis
Yemen
Spain
0.54
0.85
0.63
0.07
0.70
0.95
0.89
0.53
0.59
0.62
0.35
2600
21000
258
4850
1900
4280
1644
185
1670
2800
8000
1680
17800
90
900
1570
3014
240
150
460
700
300
* 0.65
* 0.85
0.35
0.19
* 0.82
* 0.70
0.15
* 0.81
0.28
0.25
0.04
Foster y Loucks, 2010
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8. Legal conditions of groundwater in Spain
Water Act 1866  all water in public domain
1879  groundwater in the private domain
1985  all water is a public domain
 to avoid expropriation of existing groundwater rights:
• right holders • could accept public protection by giving their rights
maintain the rights for 50 years
preference for a concession
go to a registry
• could preserve their rights forever
but without changing well characteristics (??)
go to a catalogue
• reality  few owners have changed their status
pre–law development was already intensive
 most groundwater is private in practice
 the inventory of groundwater rights is very incomplete
 overexploitation areas can be declared by water authorities
 a complex and poorly effective procedure
owners in overexploited areas have to
 reality is mostly a failure
 groundwater users are public entities  some effective ones formed bottom–up
2001  incorporation of the European Water Framework Directive
 successive modifications  European “Groundwater Directive”
 the main problems are not properly addressed
adapt their abstraction
form an users’ association
(top–down)
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9. Spanish aquifers in which “overexplotation” problems were officially identified in
1996 according to the Water Act and its Regulations.
DGOH–ITGE, 1987 2015–Zaragoza UN–92015–Zaragoza UN–9

10. (Custodio, 2004)
Idealized representation of
• agricultural production
• water consumption
• crop value
Shadowed plans: surfaces of equal ratio:
water cost / crop value
Groundwater cost influences its use  silent revolution
Low ratio
 high pressure for groundwater development
even illegally/allegally
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11. The MASE project
MASE = Minería del agua subterránea en España
Groundwater mining in Spain
Executed: Department of Geo – Engineering, Technical University of Catalonia (UPC)
Prepared by : E. Custodio
Finantial support: AQUALOGY
Supervision: CETaqua
Considered aspects
No specific studies. Use of data in
Areas considered: South–eastern Spain (Levante): southern Alacant, Murcia and Almeria
The Canary Islands: Gran Canaria, Tenerife
Results: evaluation of groundwater intensive use and its consequences
importance for development and prospective
groundwater mining: 12–15 km3
in south–eastern Spain
1–3 km3
in Gran Canaria and Tenerife
partial volume recovery is possible after ceasing abstraction
– there is some significant recharge
– from some decades to some centuries (?)
– in Tenerife a part of the mid–to–top island is permanently drained
existing reports and studies (non–exhaustive)
information from experts contributions
questionnaire
hydrology / hydrogeology
environment
economics
social issues
administrative issues
ethic issues
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12. Piezometric level evolution in some of the more
intensively exploited aquifers
(Cabezas, 2011, García–Aróstegui, 2013)
Average piezometric drawdown from the
start of monitoring of the main intensively
exploited aquifers
(PHS, 2013)
Segura basin.
Intensity of piezometric
drawdown
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13. Groundwater reserves, hm3
Área
Consumed,
1980–1995
Existing Usable Consumption
rate hm3
/a
Time to
depletion, years
Almería 800 1100 750 50 15 (10–75)
Murcia 2000 10000 7100 125 60 (10–80)
Alacant 1000 7000 6000 50 120 (10–400)
Valencia 100 2500 200 15 130 (20–350)
Preliminary estimation of groundwater reserve consumption.
South–eastern Spain.
Period 1980–1995
(DOGH–ITGE, 1997)
(DOGH – ITGE, 1997)
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14. South–eastern Spain and the Canary Islands
Groundwater use
(modified from De Stephano et al., 2013)
hm3
/year
Área Spain Xúquer Segura CMA Canaries
Urban 1500 320 ––– 140 125
Irrigation (C) 5000 1180 450 377 210
Industry 300 100 ––– 3 8
Recreation 65 10 ––– 20 12
Total groundwater(A) 7000 1610 485 540 355
Total water (B) 31500 3156 1850 1225 510
A/B groundw/total 0,22 0,51 0,26 0,44 0,70
C/A
irrig/groundwater
0,71 0,73 0,93 0,70 0,59
Use and economic value of groundwater for agriculture
(modified from De Stephano et al., 2013)
Main water courses
desalinization plants and
aquifers in South–eastern
Spain
Área Spain Xúquer Segura CMA Canaries
Total irrigated surface, 103
ha
Groundwater irrigated surface, 103
ha
3345
945
490
160
200
70
210
85
25
25
Total use, hm3
/a
GW use hm3
/a
12000
3220
1655
535
800
270
755
310
170
170
Production, M€/yr, for total
Production, M€/yr, for GW
15300
4730
2260
410
1450
585
2460
1385
340
340
GW / total use 0,31 0,18 0,40 0,56 1,0
Prod. / surface for total €/ha 4600 4600 7200 11700 13600
Prod. / surface for GW €/ha 5000 2600 8400 16300 13600
Prod. / use for total €/m3
1.3 1.4 1.8 3.3 2.0
Prod. / use GW €/m3
1.5 0.8 2.2 4.5 2.0
Endowment for total m3
/ha/a 3590 3380 4000 3600 6800
Endowment for GW m3
/ha/a 3410 3345 3860 3650 6800
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15. Gran Canaria Tenerife
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16. Evolution of the Gran Canaria Island aquifer
Variación anual
Evolución de la reserva de agua subterránea
1972 SPA15 2006
2125 hm³
814 hm³
Consejo Insular de Aguas de Gran Canaria, 2009
Evolution of groundwater reserves
Annual changes of groundwater
reserves
Water table drawdown in a high–altitude, deep
borehole
Effect of groundwater abstraction reduction due to
the high cost of getting it
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17. Groundwater balances
Tenerife Island
Decade 1971–1980 1981–1990 1991–2000 2001–2005
Input, hm3
/a
Recharge 338 321 235 279
Irrig. return flows 93 55 38 27
TOTAL 431 376 273 306
Output, hm3
/a
Abstraction 218 213 205 188
To the sea 399 342 294 266
TOTAL 617 555 498 456
Reserve decrease 186 179 225 148
Evolution of groundwater balance components
(ETITF, 2008)
(PHTF, 2010)
Desalination; Wastewater reclamation; Surface water; Springs; Wells; Water galleries
Large water table drawdown
Important groundwater outflow to the ocean
Large rock volume drained by mid– and high–
altitude water galleries
 non–recoverable
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18. Júcar River flow decrease due to development of the La Mancha Oriental aquifer for
agricultural irrigation at the upstream part of the basin.
MIMAM, 2000
Environmental effects: on rivers
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19. Evolution of spring flow, Bco. Azuaje
Effects of intensive groundwater exploitation in
northern Gran Canaria Island
Barrancos (gullies) de Moya y Azuaje
Hernández–Quesada et al., 2011
Cabrera et al., 2014
Evolution between 1970 y 2008
springs
environment
other GW developers
Large effects in
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20. Environmental effects: Doñana National Park
Groundwater discharge flow evolution to La Rocina
ravine and to La Vera ecotone
Calculated by groundwater flow numerical modelling.
Dramatic situation of 1994 combined effect of:
1) accumulated water level lowering due to pumping,
2) a 4 years–long drought
Groundwater level above mean sea level (m)
Natural conditions
October 1992
Disturbed conditions
October 1996
Groundwater flow pattern
modified from UPC, 1999
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21. TABLAS DE DAIMIEL NATIONAL PARK
NATURAL STATE
Significant
decrease in
piezometric levels;
more than 30 m
DISTURBED STATE
Environmental impacts: Las Tablas de Daimiel wetlands
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22. • Groundwater abstraction cost is high in areas with groundwater mining: 0,4 to 0,5 €/m3
but it is still cheaper than other water put in the area
subsidies distort the concurrence
• Farmers and suppliers will continue using groundwater, beyond regulations
regularly
in droughts
as a security
• Water trading is appearing, highly controlled by water authorities
owners are reluctant to sell since they fear losing their rights
but trading exist between private owners
• Water trading is a well–established fact since one century in Gran Canaria and Tenerife
a king of water markets functions, approaching free markets
the water authorities sell and buy water in markets
public intervention tame the prices but decreases public investment
• Groundwater mining is a fact and will continue if subsidized water is not provided
•The main deterrent to groundwater mining are not regulations but
• the increasing control of energy
in some cases groundwater quality deterioration
• Environmental effects are poorly known and valued and mostly happened decades ago
is difficult
recovery may be at a disproportional cost
may produce damage in some areas
• Ethical aspects are tamed by the fact that some slow recovery is possible
involve the need of a change of paradigm  a difficult task
monitoring
groundwater users have to be involved in surveyance
decision making
civil society should recover from current poor activity and concern
Some additional considerations
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23. Prospective
A more flexible Water Act is needed
 the poor flexibility of water rights and concessions need to be solved
A water pact is needed among all interested actors and especially political parties
 the seed is on the mind
Groundwater mining is not necessarily a devil and in some cases it is good
it should be controlled
benefits should be used to compensatefor current and future damage
it has to be considered a transient situation with some dead end
Groundwater mining experience has to be improved
 study experience in other parts of the World
 develop the GWM project to compile worldwide existing experience
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