Future Groundwater Resources at Risk (Proceedings of the Helsinki Conference, June 1994). IAHS Publ. no. 222, 1994. 389

Regulatory issues mainly about aquifer over-exploitation within the scope of sustainable development

F. VILLARROYA Spanish Committee of International Association of Hydro geologists (IAH), Departamento de Geodinâmica, Facultad de Ciencias Geolôgicas, 28040 Madrid, Spain

Abstract A detailed analysis of the aquifer overexploitation indicates that the definition is unclear and controversial. There is no valid definition for every situation. In the majority of cases it is similar to inadequate use of the aquifers, in others it is the result of planned them. In Spain, overexploitation of aquifers comes within the Water Act, and is treated within the Regulations that develops the Act. Experience has shown that without the cooperation of the Water Users, good results cannot be obtained. Adequate education is urgently needed for the population in general, and also for those who take the important decisions necessary to obtain the correct use of hydrogeological resources for present and future generations. For adequate exploitation of aquifers it is necessary to establish some restrictions which will preserve the quality as well as the quantity of the aquifer. The zones of protection for aquifers and wells take an important place within these constraints.

INTRODUCTION

The beginning of the nineties is characterized by considerable concern for those subjects concerning environment, and the sustained use of those resources necessary for humanity today which will not destroy those necessary for future generations. It was a commendable effort. The Earth is smaller than ever, it is our communal village. Among the conferences that have dealt with this, directly or indirectly in the last three years, we can mention the following: UNDP Symposium on "A Strategy for Water Resources Capacity Building", held in 1991 in Delft (The Netherlands); 23rd Congress of IAH on Aquifer Overexploitation held in the Canary Islands in 1991; International Conference on "An Agenda of Science for Environment and Development into the 21st Century" (ASCEND 21), held in Vienna in 1991; the International Conference on Water and the Environment, held in Dublin in 1992; the United Nations Conference on Environment and Development (UNCED), held in Rio de Janeiro in June 1992. The 2nd International Conference on Environmental Pollution held in Sitges (Catalonia, Spain) and, finally, the present Conference on FGR 94.

During the last five years there has been considerable debate and discussion over the use of the term overexploitation of aquifers, especially in Spain. Within the framework of this congress FGR 94, the question of whether manifestations of overexploitation are real risk or concern for lack of resources in the near future can be asked. This will try to be answered in this paper.

390 F. Villarroya

Some important studies on this subject have been published by the International Association of Hydrogeologists-Spanish Committee (AIH-GE). The AIH-GE organized two scientific monographic meetings on this subject, one in 1989 and one in 1991. In both Congresses the problem of aquifer overexploitation was discussed. The second one took place within the 23rd Congress of the IAH. References from both of them form the important work on the subject (Pulido et al., 1989; Candela et al., 1991). Also in 1991 a workshop on this subject, convened by UN-DTCD (Dijon & Custodio, 1992), took place in Spain. Finally the IAH has published a selection of the papers presented at the 23rd Congress of IAH (Simmers et al., 1993) which is the latest published book on this subject. Part of the data mentioned in this paper are taken from these bibliographical references.

ARE FUTURE GROUNDWATER RESOURCES AT RISK?

To answer this question we shall study the quantity and quality of groundwater. According to the data provided by Shiklomanov (1990), WRI (1990), Margat (1991), Llamas et al. (1992), and Elligsen & Banks (1993), we can say that water is one of the most pervasive substances on Earth. Its total volume is about 1400 million km3, but 98 % of this water can only excite the eye and the imagination, because it is the saltwater of the oceans, inland seas, and deep underground basins. The remaining 2% is freshwater. Nature guards jealously the greater part of this: 87% is locked in ice caps and glaciers and most of the rest is groundwater (WRI, 1990). The current rate of withdrawal is about 3500 km3 per year, some 2100 are for consumptive use, the remaining 1400 km3

of waste water are returned to rivers. The withdrawals (percent by sectors) are: domestic (8), industry (23) and agriculture (69). Margat (1991) and Kraemer (1993) insist on the necessity in improving the evaluation of water.

Table 1 taken from Margat (1991) shows the degree of utilization of groundwater in many countries. According to this Table the first 15 countries are as follows (in km3

per year): India 150; USA 101, China 74.6; USSR (former) 45; Pakistan 45; Iran 29; Mexico 23; Japan 13.1; Italy 12.1; Germany 9.5; Saudi Arabia 7.4; France 7; Spain 6.3; Turkey 5 and Madagascar 4.9.

What about the quality?

Groundwater pollution by diffuse or by point sources is the main current problem and will be in the near future, at least in developed countries (Llamas, 1991). Groundwater quality protection seems to be the key issue today in groundwater resources policy in the industrialized countries, and it will also be in the near future in developing countries. There are a lot of sources of risk for groundwater as shows RIVM & RIZA (1991). The seminar on groundwater for the UE countries finds the problems and threats, which appear in Table 2. The conclusion is that in all the UE countries current practices lead to a non-sustainable use of groundwater systems. No less dramatic is the call made from the Dublin Statement: "Human health and welfare, food security, industrial development and the ecosystems on which they depend, are all at risk, unless water and land resources are managed more effectively in the present decade and beyond than they have been in the past" (WMO-UN, 1992).

Regulatory issues mainly about aquifer over-exploitation 391

Table 1 Groundwater abstractions in several countries.

NATION

AFRIQUE DU SUD

ALGERIE

CAP VERT

EGYPTE

LIBYE

MADAGASCAR

MALI

MAROC

MAURITANIE

NIGER

SENEGAL

SOMALIE

SOUDAN

TUNISIE

CANADA

USA

MEXIQUE

ARGENTINE

PEROU

CUBA

ARABIE SAOUDITE

BANGLADESH

CHINE

CHYPRE

COREE DU SUD

EMIRATS ARAB ES U

INDE

IRAQ

IRAN ISRAEL

JAPON

JORDANIE LIBAN

OMAN PAKISTAN

PHILIPPINES SYRIE

TAIWAN

THAÏLANDE

TURQUIE

YEMEN DU NORD

YEMEN DU SUD

AUSTRALIE

YEAR

1980

1985

1980

1985

1985 1984

1989

1985

1985

1988

1985

1985

1985

1985

1980

1985

1985

- 1975

1973

1975

1985

1979

- 1985

1985

1985

1985

1979

1985

1980

1986

1980

1980

1985

1985

1985

1980

1980

1985

1976

1980

1985

1985

1975

1983

WITHDRAWALS

Total in 10 m3/year

1.79

2.0

0.03

3.4

2.1 4.76

0,1

3

0.88

0.13

0.26

0.3

0.28

1.23

2,19

101,3

23.5

4.2 2

3.8

7,43

3,4

74.6

0.4

1.2

0,39

150

0.2

29

1.2

11.8

13.1

0.41

0.60

0.56

- 45

4

3,67

3,2

0,7

5

1

0,35

2,46

% Total Withdraw.

13

59

80

6,4

100

29

27

47

9

3.5

1.3

53.5

5,7

21.7

41

15

47

89

- 15

74

8

80

35

0.5

~ 40 67

13.9

15.8

31

12

29

29

- 13

14

19

32

32

18

14

NATION

ALLEMAGNE (RFA)

ALLEMAGNE (DDRl

AUTRICHE

BELGIQUE

DANEMARK

ESPAGNE

FINLANDE

FRANCE

GRECE

HONGRIE

IRLANDE

ISLANDE

ITALIE

LUXEMBOURG

NORVEGE

PAYS-BAS

POLOGNE

PORTUGAL

ROUMANIE

ROYAUME-UNI

SUEDE

SUISSE

TCHECOSLOVAQUIE

URSS

YOUGOSLAVIE

YEAR

1981

1985

1975

1980

1980

1977

- 1980

1980

1984

1980

1972

1977

1984

1979

1976

1985

1981

1980-81

1980

1975

1975

1985

1985

1983

1980

1980

1984

1980

WITHDRAWALS

Total in 10 m3/year

7,77

6.99

1,78

1.17

0,78

1,32

6,3

0,37

7,03

1,87

1.6

0,095

0,089

12,16

0.026

0.11

1,28

2,0

2,0

1,18

2,38

2.35

0.48

1.0

1.22

36

45

t . l

%Total Withdraw.

18,7

17

21,4

37

8.6

- 90

25

- I l

18.1

28,3

18,5

23.3

93.7

26

«

4.8

3,2

11.9

19

8

23,3

20

16,8

33

21

10,2

- 10

8,7

392 F. Villarroya

Table 2 Main problems and threats on sustainable use of groundwater in UE countries.

Urban and industrial threats

Agricultural threats Other threats

Landfills Surface impoundments Injection and underground storage Hazardous waste sites Dredged sediments Mining waste Fuel storage tanks Line sources

Nitrate: use of manure Nitrate: Use of fertilizers Nitrate: total nitrogen load Nitrate: air deposition Nitrate: sensitivity of European soils to nitrate leaching Nitrate: estimation of the actual nitrate leaching Nitrate: actual pollution based on monitoring data Phosphorus Potassium Pesticides: their use Pesticides: atmospheric deposition Pesticides: sensitivity of soils to leaching of pesticides Pesticides: computed pesticide leaching Pesticides: monitoring data Pesticides: ecological threats

(Heavy) metals Acidification and the risks of aluminium leaching Lowering of groundwater levels by overexploitation Lowering of groundwater levels by regulation of surface waters Lowering of groundwater levels by intensified drainage Lowering of groundwater levels by changes in land use Raising of groundwater levels by stopping extractions and artificial recharge Economic consequences Ecological consequences Threats to sustainability of groundwater use: — Threats to functionality of

groundwater — Threats to the diversity of

ecosystems

In short, future dangers in the utilization of groundwater are derived more from the quality of the water than from the quantity. It is understandable that within the framework of the International Hydrological Programme (IHP-5) sponsored by UNESCO from 1996-2001 is "Hydrology and water resources development in a vulnerable environment", and that one of the most important points of the investigation is precisely "Groundwater resources at risk". This theme would deal with the following topics (UNESCO, 1992): — Groundwater contamination inventory. — Monitoring strategies for detecting groundwater quality problems. — Role of unsaturated zone processes in groundwater supply quality. — Groundwater degradation in coastal regions. — Groundwater contamination due to urban development.

SUSTAINABLE DEVELOPMENT AND GROUNDWATER RESOURCES EXPLOITATION

The main task of this Congress is centred on the durability, in the near future, of groundwater resources with the quantity and quality necessary for their various uses.

Each one of the terms (sustainable development,resources at risk and aquifer overexploitation), are or have been the object of multiple meetings, specially after the World Summit which took place in 1992. The term "sustainable development" has been criticized because of the contradiction in uniting growth with sustainability; seemingly incompatible.

Regulatory issues mainly about aquifer over-exploitation 393

The most important thing is to solve the problems as they appear, and not spend time and energy in defining the three terms. One can say that any exploitation of hydrological resources — independently of its recharge/exploitation ratio- that is separated from an integrated management programme of the water resources united to the welfare of present and future generations, is pernicious, because of lack of solidarity with a common cause; and as such is non-sustainable, and puts at risk by quality or quantity or both at the same time, the water resources. It would be a highly undesirable situation in which the terms here analyzes: risks in the use of groundwater resources, sustained development and overexploitation of aquifers, were produced at the same time.

How can sustained development and exploitation of water resources become compatible?

First it would seem that a water policy which only considers the comfort of the present generation, and with no moral sense is not good. Many of the problems which goad us today, and among which water and the growing deterioration of the environment are an insignificant tip of iceberg, derive from a crisis in human values, and to speak plainly from a profound moral crisis. In agreement with Llamas (1991, 1993), the three basic principles for new management are : solidarity, subsidiarity and involvement. Their practical application should be different from country to country but it will always demand a relevant effort in education and information to the general public. We will come back to this subject later.

What do we mean by sustainable development?

For Fyfe (1993) it means: will I leave this planet in a better condition for all species which follow me than when I arrived? or, do my actions restrict the opportunities for all those who follow? In a sense, we are asking if we are using resources needed for our life support system with wisdom.

For the UICN-PNUMA-WWF 1991 (inKraemer, 1993), sustainable development consists in improving the quality of human life by adapting it to the capacity of the basic ecosystems.

The last seminar of ministers of Environment of UE countries established that "the sustainable use of groundwater basically requires two conditions: no loss of groundwater potential functions and preservation of the diversity of the ecosystem and maintenance of the biodiversity" (RIVM & RIZ A, 1991). But the general conclusion is that in many countries sustainable use of groundwater for drinking and other groundwater functions is being threatened specially in the agricultural and industrial core regions of the UE.

For the Dublin Statement sustainable water resource development is development that promotes the quality of human existence and the natural functions of the biosphere.

If development is defined in terms of economic growth, then the concept of sustainable development becomes questionable, perhaps even a contradiction in terms vis a vis the environment, unless of course growth can be shown to be beneficial or at least not damaging to the environment. Because economic growth and ecological sustainability seems to be incompatible, and if development is taken as equivalent to

394 F. Villarroya

growth - "sustainable growth" - then, Martinez Alier (1993), proposes the "ecological economy" as a less controversial formula than sustainable development.

The IAH statement for the Dublin Conference defines the sustainable development in the following way: - Sustainable management of groundwater quantity. In the long term groundwater

should not be exploited beyond the limits set by the rate of replenishment. Short term overdraft on renewable resources may be an acceptable and economic method of water use in special cases. The environment has to be recognised as a legitime demand upon groundwater resources: the maintenance of the ecosystems is a new constraint in management.

- Sustainable management of groundwater quality. The only truly sustainable methods of groundwater quality management are those which are based upon the concept of prevention because they provide the only approach which protects the total groundwater resource.

- Integrated management. Issues of quality and quantity cannot be separated. An integrated approach must also be adopted with respect to interrelations with surface water systems.

- Training and education. This is also named Soft Hydrogeology or "Sciency " (Fyfe, 1993). If water users, municipality officials, industrialists and farmers, and those who take decisions on land use, planning and waste management do not understand the basic concepts of groundwater use and protection then we cannot hope to manage our groundwater resources and the substantial environmental interests which depend upon it adequately. The paper presented by Llamas et al. (1992) summarizes the suggested actions for

sustainable development.

Aquifer exploitation and sustainable development

These questions have been dealt with authoritatively by Margat (1993). This author speaks of malthusian sub-exploitation in the case of inadequate use (by infra-utilization) of an aquifer. Custodio (1993) has dealt with this subject recently. According to this author "intensive aquifer exploitation is a source of wealth, which fosters regional development and helps to guarantee supply until other water sources can be economically developed", or is a simple way to postpone a water supply problem.

But groundwater overexploitation has a series of negative consequences such as increasing water cost, environmental changes, diminishment of other water resources already used, water salinization, and impairment of quality." The net result may be either negative or positive. Positive results dominate at regional level, but negative results are "news" that trigger alarm whistles and malthusian forecasts under the heading of overexploitation" (Custodio, 1993). Meinzer developed the concept of "safe yield" when the water that can be abstracted permanently from an aquifer produces no undesirable results. This concept is used manly by managers and engineers. On the other hand, intensive exploitation or overdraft are mainly points of view, referring to the consequences of intensive groundwater use, as perceived by environmentalists, news media, and public in general, and places more emphasis on the adverse or detrimental aspects. So to evaluate groundwater exploitation, not only negative effects have to be

Regulatory issues mainly about aquifer over-exploitation 395

considered, but also positive ones. Otherwise a "biased appraisal may be reached. Normally practice shows us that beneficial aspects dominate over detrimental ones in most practical situations" (Custodio, op. cit.). According to this last author,the most detrimental cause of aquifer exploitation is ignorance of what is happening, and negligence in producing the data needed to evaluate the hydrogeological and economical situation correctly. Another detrimental effect is the irresponsible overreaction of water authorities, especially when they are poorly informed or lack the scientific and technical skills to evaluate actual problems correctly.

" Sustainable development must satisfy present needs without jeopardizing the ability of future generations to satisfy theirs. Sustainable development of groundwater is an objective to be accomplished inside the regional set of water resources and not at aquifer level, although it may be so if the intrinsic strategic value of an aquifer is considered. A given aquifer may be allowed to be intensively exploited if the benefits compensate and are applied to correct undesirable effects. Overexploitation may take place during a period to allow better integration of other elements resources, or while other technologies are developed. Uncontrolled aquifer development easily leads to extensive aquifer exploitation and even to hard forms of overexploitation" (Custodio, 1993).

LIMITATIONS IN THE EXPLOITATION OF GROUNDWATER RESOURCES AND VULNERABILITY ANALYSIS

Concern for the quality of water and the effect that aquifer exploitation can have on ecosystems grows day by day (Llamas, 1989). There are various standardized methods to evaluate the degree of real or possible influences of different sources of contamination. Outstanding among them are those by LeGrand (1980) and Aller et al. (1987) (DRASTIC), that have been widely used in different countries. To evaluate the risk of contamination from waste disposal, Legrand developed a method that has later been modified so as to be more easily adapted to each case. The system focuses on considering four key geologic and hydrogeologic characteristics in the vicinities of sources contamination. The key parameters are: 1 distance to a water supply, 2 depth to water table, 3 hydraulic gradient, 4 permeability-sorption, as indicated by the geologic setting.

The DRASTIC method has also been used with success in numerous occasions. The system has two important parts: the selection of mappable units, termed hydrogeologic settings, and the superposition of a relative rating system called DRASTIC.

Hydrogeologic settings form the basis of the system and incorporate the major hydrogeologic factors which affect and control groundwater movement including : D — Depth to water, R — Net Recharge, A — Aquifer media, 5 — Soil media, T - Topography and slope, I — Impact of the vadose zone media, C - Conductivity hydraulic of the aquifer.

396 F. Villarroya

Groundwater protection areas. Groundwater quality monitoring

Several european countries and USA have experience on areas of protection for wells supplying towns. Especially prominent is the work of Van Waegeningh (1985a,b) has been used especially in three types of aquifers: porous permeable rocks, fissured rocks, and limestones. In Spain there has been very little experience up to now. Nevertheless it seems that it is going to be of prime importance now, according to the future National Hydrological Plan, the perimeters of protection for the sources of drinking water for population of more than 15 000 inhabitants should be established before the year 2002, while for the second phase envisaged by the Plan, the perimeters for population of more than 2000 inhabitants supplied by wells, should be established before the year 2012.

Land-use planning and groundwater protection management in rural areas is not an isolated programme. Two categories of groundwater protection management can be considered: general protection of groundwater resources and comprehensive protection of groundwater around public water supplies.

General protection of groundwater is based on the assumption that all effectively accessible groundwater resources are, or will be, tapped for drinking or other purposes, and therefore their protection is desirable. Under water management plans, national, regional or local governments and water authorities should therefore bear the responsibility for, and financially support the protection of unused groundwater resources.

Implementation of general protection of groundwater resources calls for the following activities: - investigation of the groundwater system and determination of its vulnerability; - identificationjisting and assessment of the existing and potential pollution sources; - monitoring of the groundwater system.

Comprehensive groundwater protection is mostly concerned with public water supplies. The groundwater resources utilized for public drinking water supplies are defended by zones, referred to as wellhead protection areas in the USA, usually comprising two or three levels of protection. The main purpose of groundwater protection zone delineation is to defend drinking water supply wells or wellfields from pollution and provide the population with water which meets the standards for drinking water. In several countries, wellhead protection is an obligatory part of groundwater protection policy and strategy programmes, and is based on the relevant legislation.

First level groundwater protection zones defend the well and its immediate environment from mechanical damage and direct, pollution. Their extent is usually small (several tens of square metres at the maximum). They exclude all activities.

Second and third level groundwater protection zones are extensive (several hundreds of square metres to several square kilometres) and include the discharge areas, the cones of depression (zone of influence) around pumping wells, the recharge and contribution areas and other vulnerable areas of a given water supply system.

In several European countries, the second level zones cover areas having a delay or residence time of 50 to 60 days. It should be emphasized that the delay time has been determined so as to protect water supply wells from the risk of groundwater microbial contamination, but it may become inadequate for certain chemical pollutants.

The third level zone protects groundwater quality in water supply wells from persistent chemical pollutants. It is the most extensive zone, but there are less restrictive

Regulatory issues mainly about aquifer over-exploitation 397

measures (after Vrba & Van Waegeningh, 1991; Lallemand & Roux, 1989, and Matthess et al., 1985).

Groundwater quality monitoring plays an important role in groundwater protection and quality conservation (Vrba & Pekny, 1991). These authors are referring to that in former Czechoslovakia groundwater quality monitoring is undertaken by three types of network: national, regional and site specific monitoring and pilot stations. The national groundwater monitoring programme is coordinated with surface water, climate, precipitation, and soil monitoring.

REGULATORY ISSUES RELATED WITH AQUIFER OVEREXPLOITATION

In the Introduction reference is made to some bibliographical sources concerning over-exploitation of aquifers. After reading all these, it is clear that there is no clear definition of this expression. The most recent definition of overexploitation is that which appears in the International Glossary of Hydrology edited by UNESCO (1993). Where it is understood that there is overdraft when extraction are being made which exceed the ideal. Spanish Legislation (Reglamento del Dominio Publico Hidrâulico. Royal Decreet 849/1986) defines it in article 171.2 in the following terms: "An aquifer shall be con­sidered to be overexploited, or in danger thereof, if the subsistence of the reserves existing therein are being placed in immediate danger as a result of annual withdrawals that are in excess or very close to, the average annual volume of the renewable annual resources, or which give rise to serious deterioration in the quality of the water" (ITGE, 1991).

According to Dijon & Custodio (1992), passing the limits of renewal resource is not necessarily overexploitation or to stay within the limits of the same does not necessarily imply that all undesirable effects are avoided and the beneficial effects enhanced.

There have been various commentaries about the ambiguity of the terms used (Pulido etal., 1989; Candela etal., 1991; Simmers etal., 1993; Llamas, 1992; Fink, 1993; Delgado, 1992). This last author suggest a rational definition of this term with the following formulation; "all exploitation which causes undesirable effects with in the aquifer itself, or outside it, within a certain time, respecting the uses and objectives desired and the social-economic context of the region. "

Llamas (1992), suggests either the elimination or a very restricted use of the term. In brief, he defines overexploitation "sensu stricto" as all extraction of groundwater which has the effects (physical, chemical, economical, ecological or social) which are in the end, negative for human life, now and in the future. Obviously this type of overexploitation should be avoided for moral reasons. For exploitation based on the extraction of water superior to the average recharge of the aquifer he suggests the term "overexploitation sensu latu".

In the meeting of those responsible for the environment from UE countries (RIVM and RIZA, 1991, page 47), a situation where the groundwater flow to rivers and lakes diminishes considerably and may endanger the river-dependent functions, can also be considered as overexploitation.

In the papers presented at the 23rd International Congress of IAH, in which the author of this article was the president of the Organizing Committee (Candela et al., 1991), it was stated that in many cases overexploitation is synonymous with inefficient

398 F. Villarroya

exploitation of an aquifer (Villarroya, 1992; Villarroya & Rebollo, 1993). In this Congress numerous examples of situation of overexploitation all over the world were presented, A summary of these contribution can be found in Dijon & Custodio (1992).

After all that has been said up to now it is not surprising that authors like Custodio (1991), suggests substituting the term overexploitation for that of excessive exploitation.

Margat (1993) suggests a vocational use of aquifers that in some cases could suppose and justify a mining use of water, using a strategic reserve to be used only once.

OVEREXPLOITED AQUIFERS, LAND USE PLANNING AND REGULATORY COMPLIANCE

In Spain groundwater is public property since the 1985 Water Legislation. For this reason any well which has a yield of more than 7000 m3 a4 must have an official licence. The Water Authority of the basin (L.A., art. 54) can denounce the overexploitation of an aquifer and at the same time order a limitation of the extractions of water to achieve a more rational exploitation. Areas where no new exploitation may take place, can be designed.

What steps can be taken when an aquifer is declared overexploited? Under the Water Act the following procedure can take place (Art. 171, 172 and 173): - Provisional denouncement of overexploitation and delimitation of the affected area. - Paralyzation of concessions for the utilization of groundwater including wells with

less than 7000 m3 a"1 (except in water including wells with in rare cases). - The compulsory formation of a Water Users Community if it does not already exist. - The Water Authority works out a methodical Plan of Extractions after consulting the

Water Users Community, submitting it to public information and it will be reported on by the Water Board of the river basin.

- Finally, the River Basins Executive Committee will approve the Plan which supposes that aquifer is declared definitely overexploited.

- The hydrological Plan for the river basin will be modified to adjust it to the declaration of overexploitation.

- Meters may be installed to control the exploitation. - To enforce the measures ordered under the Plan an Exploitation Committee will be

formed which give an Annual Report on the situation. - The Water Authority can authorize perimeters restricting new concessions of

groundwater and should order the formation of a Water Users Community. In this way there is a control of activities or uses within the perimeters which can affect the quality or quantity of the groundwater and which should count on the support of the Water Board. These activities could be: mining, urbanization, agriculture, cattle-raising, industry and recreation.

How can the lack of water resources affect land planning?

As we have first seen the overexploitation of an aquifer has a marked influence on the planning and uses of land.

Water Users Community will have to play a very important part in the exploitation of natural resources in general and specially in water resources. Certainly the

Regulatory issues mainly about aquifer over-exploitation 399

participation of citizens through NGOs as in the Consumers Community of aquifers has been shown to be very efficient and, in many occasions has alleviated serious problems concerning the exploitation of the hydric resources of a region (Galofré, 1991). They have also been shown to be efficient instruments as vigilantes to ensure that restrictions and regulations are being complied with. In this sense the Water Authorities should treat them as collaborators and no obstacles.

Also at international level one finds situations in which groundwater plays an important role. There are authors who emphasize the strategic importance that ground­water plays in securing independent supply, at least temporally. A clear example of this is seen in the near eastern countries. Margat (1992) differentiates three types of situation: (a) Countries with renewable resources (therefore without dependence on the exterior) :

Lebanon, Yemen, The Cisjordan and Magreb states. (b) Countries without renewable resources which do water-mining; The Arab Emirates,

Qatar, Oman, Syria, and Saudi Arabia. Soon or later, they will become dependant on the exterior.

(c) Countries which depend heavily on others; Egypt, Sudan, Syria, Iraq, Israel, and Jordan. Margat foresees a different future of "interchanging water for oil" between there

countries, and the establishment of new relations forced by lack of water. Shamir (1993, page 10) goes even further and considers water to be an extremely factor in peace negotiations. In conclusion, water is not only a valuable resource but also an instrument in producing peace between neighbouring countries.

INVOLVEMENT AND EDUCATION

This is the key for the future of water management. All the scientific reunions in the last few years have emphasized these aspects (Congresses of Dublin, Delft, Vienna, etc. and also, Fyfe, 1993; Ellingstone & Banks, 1993; Llamas, 1993). Fyfe (1993) calls this new philosophy, which should influence all managements of natural resources, "Sciency".

Solidarity, subsidiarity and participation are the three great axes on which Llamas (1993) bases sustained development. Certainly solidarity must be established between the present generation and the future ones. For this reason moderation in the use of resources must be our normal behaviour. Subsidiarity implies the transferring, without hope of excessive gain, of the necessary technology between different countries. Fortunately our young people are taking great strides in this direction.

Lastly, the critical participation of citizens should motivate those responsible for water management and induce them to surpass themselves in their effort.

In this way Water Users Community, which are envisaged in Water Acts like the Spanish one, should not only be considered as legal figures but also be used as efficient tools, for the good management of aquifers. Also scientific and professional associations, like the International Association of Hydrogeologists must endeavour to increase their influence over society and in those centres where decisions over water are taken. The IAH Council in the Prague meeting (1992) debated the lines to be followed at the beginning of the next century and insisted on the so called "soft hydrogeology " as a priority to be acted on in the next few years. The new President of the IAH,

400 F. Villarroya

Prof. J. Moore, has insisted on these terms. Will the IAH accept the challenge and fulfil it? This is what we are working on.

CONCLUSIONS

In the near future dangers in the utilization of groundwater arise more from problems of quality than quantity. Towards the end of the century the implementation of measures to prevent pollution of groundwater - by diffused or point sources - are to be the principle issue. The groundwater protection areas are formed as useful ways of protecting the quality of the waters.

Groundwater resources used for public drinking water supplies are defended by protection zones (or wellhead protection areas) usually comprised by protection zones of two or three levels. Groundwater quality monitoring plays an important role in groundwater protection and quality conservation. Besides these networks for the control of the quantity or quality, the Water Users Community Boards are efficient in solving problems and watching over the correct working of the Working Plan.

The definition of aquifers overexploitation is unclear and controversial. In the majority of the cases it is similar to inadequate use of the aquifer, in others it is of a planned result.

To evaluate groundwater exploitation, not only negative effects have to be considered, but also positive ones otherwise a biassed appraisal may be reached.

Spanish Legislation indicates the steps to be taken when an aquifer is declared overexploited giving special importance to the compulsory formation of a Water Users Community and elaboration of a Working Plan for the extractions. At the same time the Water Authorities can find zones of protection with restrictions on the use of the aquifer. The application of these rules is controversial and can have great political importance.

Only with solidarity, subsidiarity and involvement can be obtain sustained groundwater development. Their practical application demands a relevant effort in education and information to the general public. Scientific associations like IAH and NGOs should take part in this process.

Acknowledgements Emilio Custodio, Ramon Llamas and Javier G. Yélamos provided valuable revision and suggestions during the preparation of this paper.

REFERENCES

Aller, L., Bennet, T., Lehr, J. H., Petty, R. & Hackett, G. (1987) A standardized system for evaluating groundwater pollution potential using hydrogeological setting (DRASTIC). NWWA/EPA Series EPA 600/2-87-035. NWWA.

Candela, L., Gomez, M. B., Puga, L., Rebollo, L. F. & Villarroya, F. (eds) (1991) Aquifer Overexploitation (Proc. XXIII International Congress). IAH (Spanish Chapter), Madrid.

Custodio, E. (1991) Characterisationof aquiferoverexploitatiomcommentson hydrogeologicatandhydrochemicalaspects: the situation in Spain. Proc. of XXIIIInternational Congress, vol. 1, 3-19. IAH (Spanish Chapter), Madrid.

Custodio, E. (1993) Aquifer intensive exploitation and overexploitation with respect to sustainable development. Proc. of Environmental Pollution ICEP.2, 509-516. European Centre for Pollution Research.

Delgado, S. (1992) Sobreexplotaciônde acuiferos. Una aproximaciônconceptual (Aquifer overexploitation: one approach). Hidrogeologiay RecursosHidrâulicos 25, 469-476. Asociaciôn Internacionalde Hidrologîa Subterrânea.

Regulatory issues mainly about aquifer over-exploitation 401

Dijon, R. & Custodio, E. (eds) (1992) Groundwater overexploitation in developing countries. Report of an Interregional Workshop (Las Palmas, Canary Islands, Spain). United Nations, Department of Technical Cooperation for Development, New York.

Ellingsen, K. & Banks, D. (1993) An introduction to groundwater in Norway - Promotion and reconnaissance mapping. Proc. of XXIV Congress of IAH (Oslo Norway), vol. 2, 1031-1042.

Fink, M. (1991) Overexploitation and permissible exploitation of groundwater. Proc. ofXXIIIInt. Cong. IAH, vol. 1., 55-60. IAH (Spanish Chapter).

Fyfe, W. S. (1993) Sustainable resources for ten billion. It is possible? Proc. Geologia Ambiental y Ordenaciôn del Territorio, vol. 1, 27-32. Sociedad Espanola de Geologfa Ambiental y Ordenaciôn del Territorio, Madrid.

ITGE (1991) Sobreexplotaciônde acuiferos. Anâlisis conceptual (Aquifer overexploitation. Conceptual analysis). Instituto Tecnolôgico GeoMinero de Espana, Madrid.

Galofré, A. (1991) Las Comunidades de usuarios de aguas subterrâneas: experiencias en la gestion y control de los recursos hidrâulicosde Cataluna (Waters users communities: experiences from Catalonia). Curso Internacionalde Hidrologia Subterrânea, Hidrogeologia, Estado Actual y Prospectiva, 337-359. CIMNE, Barcelona.

Kraemer, O. (1993) Evaluaciôn de los recursos hïdricos en apoyo del desarrollo sostenible (Assessment of groundwater resources to endanger: the sustainable development). Complutense University, Madrid.

Lallemand-Barrés, A. & Roux, J. C. (1989) Guide Méthodologique d'établissement des périmètres de protection des captages d'eau souterraine destinée à la consommation humaine. BRGM, Manuèles et Méthodes no. 19. Orléans, France.

Le Grand, H. E. (1980) A Standardized System for Evaluating Waste-disposal Sites. Nat. Water Well Assoc, Worthington Ohio.

Llamas, M. R. (1989) Groundwater and wetlands: new constraints in groundwater management. In:Groundwater Management: Quantity and Quality (Proc. Benidorm Symp., October 1988), 295-304. IAHS Publ. no. 188.

Llamas, M. R. (1991) The future of groundwater: a forecast of its exploitation and quality compared with past exploitation. Proc. 21 Journées de l'Hydraulique (Sophia Antipolis, France), vol. IV. 1-14.

Llamas, M. R. (1992)Lasurexploitationdesaquifères:aspectstechniqueset institutionnels(Overexploitationof theaquifers: technical and institutional aspects). Hydrogéologie, no. 4, 139-144.

Llamas, M. R. (1993) La crisis del agua: ;,mito o realidad? (Crisis of water). Adress in Academia Nationale dei Lincei, Roma.

Llamas, R., Back, W. &Margat, J. (1992) Groundwater use: equilibrium between social and potential environmental costs. AppliedHydrogeology, vol. 1,2, 3-14. IAH Verlag Heinz Heise, Hannover, Germany.

Margat, J. (1991) Les eaux souterrainesdans le monde. Similitudes et différences (The groundwater in the world: similitudes and differences). Proc. 21 Journées de Hydraulique (Sophia Antipolis, France), vol. IV, 1-13.

Margat, J. (1992) La lucha por el agua (The fight for water). Newspaper "El Pais " 11-6-92,40-41. World Media. Margat, J. (1993) The overexploitation of aquifers. Selected Papers of IAH, vol. 3, 29-40. Heise, Hannover.

Martinez Alier, J. (1993) Towards an ecological economy. Environmental Pollutlon-ICEP2,497 -500. European Centre for Pollution Research, London.

Matthess, G., Foster, S. & Skinner, A. (eds) (1985) Theoretical Background, Hydrogeology and Practice of Groundwater Protection Zones. AIHIntern. Contrib. to Hydrogeology, vol. 6. Heise, Hannover.

MOPT (1993) Plan Hidrolôgico Nacional (Anteproyecto de Ley). Ministerio de Obras Pûblicas y Transporte. Madrid (Espana). 95 and 253 pp.

Pulido-Bosch, A., Castillo, A. & Padilla, A. (1989) La sobreexplotaciônde acufferos (Aquifer overexploitation).Proc. of Congress National on Aquifer Overexploitation. IAH (Spanish Chapter).

RIVM & RIZA (eds) (1991) Sustainable Use of Groundwater. Problems andThreal in the European Communities. Report no. 600025001, The Hague, Holland.

Shamir, U. (1993) Development and management of groundwater resources: general principles and the case of Israel. In: Jornadas sobre las Aguas Subterrâneas. Instituto Tecnolôgico GeoMinero de Espana, Real Academia de Ciencias (in press).

Shiklomanov, I. A. (1991) The World Water Resources: How much do we really know aboutfhem? 25year Commemorative Symposium UNESCO, IMO/IHP, 93-126. Paris.

Simmers, I., Villarroya, F. & Rebollo, L. F. (1993) Aquifer overexploitation. Selected Paper of IAH, vol. 3. Heise, Hannover.

UNESCO (1992) IHP-V: Hydrology and water resources development in a vulnerable environment. Distribution limited. UNESCO, Paris.

UNESCO-WMO (1992a) International Glossary of Hydrogeology. UNESCO. Paris. UNESCO-WMO (1992b) The Dublin Statement. UN International Conference on Water and the environment (ICWE).

UNESCO, Paris. Villarroya, F. (1992) Las aguas subterrâneasen la gestion de los recursos hïdricos en Espana. (The Groundwater in the scope

of water resources management in Spain). / Congreso Hidrogeolôglco Latinoamericano. Asociaciôn Latinoamericana de Hidrologia Subterrânea para el Desarrollo, Mérida, Venezuela.

Villarroya, F. & Rebollo, L. F. (1993) Sobreexplotaciônde acuiferos: su significadoy alcance (Aquifer overexploitation: conceptand scope). Proc. Reuniônde Geologia Ambientaly OrdenaciôndelTerritorio. Sociedad Espanola de Geologi'a Ambiental y Ordenaciôn. del Territorio, vol. 1, 201-204.

402 F. Villarroya

Vrba, J. & Pekny, V. (1991) Groundwater-quality monitoring. Effective Method of hydrogeological System Pollution Prevention. Environ. Geol. Water Sci. 17(1), 9-16.

Vrba, J, & Van Waegeningh, H. G. (1991) Groundwater Pollution. In: Integrated Land-Use Planning and Groundwater Protection in Rural Areas, 43-53. UNESCO Technical Documents in Hydrology, Paris.

Waegeningh, H. G. Van (1985a) Protection of the groundwater quality porous permeable rocks. In: Matthess et al. (1985). 111-122.

Waegeningh,H. G. Van (1985b) Overview of protection of groundwater quality. In: Matthess et al. (1985). 159-167. World Resources Institute (1990) World Resources 1990-91. A Guide to the Global Environment. Oxford University Press.