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Sound and independent information
on the environment

Portugal

Freshwater (Portugal)

Why should we care about this issue

Published: 26 Nov 2010 Modified: 23 Nov 2010

Freshwater, a basic natural resource for sustaining life, plays a key role in increasing the effectiveness of land ecosystems and is essential for human and economic activity. It must therefore be protected and safeguarded, and used as efficiently as possible.

Around 64 % of continental Portugal forms part of the basins of international rivers shared with Spain. This is why the country is dependent, in terms of water quantity and quality, on regulation through the Convenção sobre Cooperação para o Aproveitamento Sustentável das Águas das Bacias Hidrográficas Luso-Espanholas [Convention on Cooperation for the Sustainable Use of Waters in Portuguese-Spanish River Basins], known as the Albufeira Convention (MAOT, 2002).

As well as the need to share water resources, other constraints have to be addressed, such as a land-use pattern favouring excessive urbanisation, with consequent pressure on water resources; an agricultural sector that consumes 80 % of the water used; and significant water losses both when it is supplied for human consumption and for agriculture (MAOT, 2002).

Despite high annual average rainfall and flow values, and although Portugal is a relatively small country, there is great spatial, seasonal and temporal variability in rainfall which is exacerbated by climate change, consequently making flooding or drought unpredictable and at times making it difficult to sustain water flows, both in national and international rivers (MAOT, 2002).

Although they are improving, waste collection and processing levels remain low and a significant number of heavily polluting industries and agro-industrial holdings continue to lack effective waste processing systems. It is also estimated that around 8 % of the population of continental Portugal (2007 data) does not have piped water in the home to meet basic needs. Sustainable water management has therefore been prioritised in various government programmes. A great deal remains to be done, however, despite the improvements brought about as a result of integrated planning under the national water plan, river basin plans, plans for the use of reservoirs and coastal development plans.

 

References

 

The state and impacts

Published: 26 Nov 2010 Modified: 08 Apr 2011

 

In 2007 the volume of water abstracted amounted to 977 563 000 m3, an increase of 7.3 % over 2006, showing that volumes abstracted continue to rise. The Algarve river basin district, in the south of the country, had a significant level of abstraction, 320 l/person/day, because it is the most prominent tourist region and consequently has a high floating population. This is something of a paradox, since it is one of the regions with the lowest average rainfall yet with the most golf courses, which consume a great deal of water. It also has the highest average temperatures and the least available water, particularly in summer.

 

Surface waters

 

In terms of water quality, the number of surface water monitoring stations recording quality as good has increased year on year, reaching 35.5 % in 2008. However the number of stations recording poor or very poor, 36.5 %, has also increased, although only slightly.

 

Figure 1 Surface water quality in 2008

Fig. 1 - Surface water quality in 2008Fig. 1a - Surface water quality in 2008
 

Source: INAG, 2009

 

For additional information on water resources

http://snirh.pt/

 

Extreme situations also occur: in the Lima, Cávado/Ribeiras Costeiras and Arade river basins, 100 % of water analysed was categorised as “good”, while the Lis/Ribeiras Costeiras, Mira, Ribeiras do Oeste and Sado river basins recorded the worst results in 2008, with 100 % of water samples from the Lis/Ribeiras Costeiras river basin being categorised as “very poor”.

 

Figure 2 Surface water quality by river basin in 2008

Fig. 2 - Surface water quality by river basin in 2008 Source: INAG, 2009

 

Nitrates

As regards nitrates in rivers, 100 % of stations recorded concentrations below 25 mg/l for the maximum, annual and winter average values. Annual and winter average concentrations in over 50 % of stations were stable. Maximum concentrations tended to decrease in over 60 % of stations. In reservoirs, more than 90 % of stations recorded maximum annual and winter average concentrations below 25 mg/l. Annual and winter average concentrations in more than 70 % of stations were highly stable. In summary, there were not considered to be any urgent situations in terms of groundwater nitrate concentration.

In the context of Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources, from 2004 to 2007 more than 90 % of stations with a groundwater level above 5 m recorded a nitrate concentration of less than 40 mg/l. In addition, more than 80 % of stations with a groundwater level of less than 5 m also recorded concentrations below the threshold of 40 mg/l. The results show that for most monitoring stations, the average nitrate ion concentration in the water appeared to be stable.

Table 2 Average nitrate concentration – Continental Portugal

TYPE

QUALITY CLASSES – Continent

Average (mg NO3/l) (2004-2007}

% Stations

 

 

< 25

25 – 39.99

40 – 50

> 50

Groundwater (0 – 5 m)

72.1

8.8

5.9

13.2

Groundwater (5 – 15 m)

89.7

10.3

0.0

0.0

Groundwater (15 – 30 m)

85.7

10.4

1.3

2.6

Groundwater (> 30 m)

92.3

5.1

0.0

2.6

Captive

100

0.0

0.0

0.0

Karst

79.3

12.4

2.1

6.2

Source: INAG / DGADR, 2008

 

To summarise the global assessment of results, in the period from 2004 to 2007 there were no urgent situations in terms of this parameter.

Eutrophication 

Eutrophication is reflected in greater primary productivity and consequently in reduced dissolved oxygen and pH levels in the water. In extreme situations this can lead to loss of fauna and flora and a reduction in the quality of water for human consumption. In order to assess the trophic status of the principal reservoirs in continental Portugal for the period from 2004 to 2007, the total phosphorus and chlorophyll-a concentration was measured in 29 stations. Some 72 %, corresponding to 21 reservoirs, are eutrophic, while 28 %, corresponding to eight reservoirs, are mesotrophic.

 

Figure 3 Development of the trophic status of reservoirs

Fig. 3 - Development of the trophic status of reservoirs

 

 

Source: INAG, 2008

 

An analysis by river basin district shows that in the 2006/2007 hydrological year the highest percentage of stations in which the status of reservoir water was categorised as eutrophic occurred in the Tejo (64 %), Sado and Mira (57 %) river basin districts.

 

Figure 4 Trophic status of reservoirs by river basin district in continental Portugal in 2006/2007

Fig. 4 - Trophic status of reservoirs by river basin district in continental Portugal in 2006/2007

 

 

Source: INAG, 2008

 

Portugal has recorded a positive, consistent and sustained improvement in both the quality of water distributed and the number of mandatory analyses for controlling such water. Data for the past decade bear witness to a clear improvement in water quality control, with a fall in percentages of missing analyses and analyses in breach of the parametric values. In 2008, sampling frequency compliance rates, percentage of analyses carried out, stood at 99.29 %, maintaining the rising trend recorded in previous years. Parametric value compliance rates also increased, rising from 97.43 % in 2007 to 97.62 % in 2008.

In terms of protecting public health, it is essential to prevent bathing water pollution. In 2008, coastal and transitional bathing waters achieved the best performance in the last five years, with 89.4 % being categorised as “good” and only 1.1 % as “poor”, with the Regional Health Authority prohibiting bathing in 0.2 % of waters. Inland bathing water recorded a decrease in compliance in relation to the mandatory values, the rate falling from 93.5 % in 2007 to 92.8 % in 2008. The same occurred with compliance in relation to the guide values, which fell by 1.2 %, from 43.5 % in 2007 to 42.3 % in 2008, a year in which bathing was prohibited in 5.2 % of such waters.

 

The key drivers and pressures

Published: 26 Nov 2010 Modified: 08 Apr 2011

One of the principal factors responsible for water body degradation is nutrient enrichment, particularly in the form of nitrogen and phosphorus, as a result in particular of the use of fertilisers in agriculture, urban wastewater discharges and the discharge of waste from agro-industry and other industrial sectors.

Table 3 shows the issues relating to pressure and drivers identified in each river basin district (RBD) in the reports on significant water management issues drawn up in 2008 in the second stage of public involvement in RBD management plans under the Law on Water and the Water Framework Directive (WFD).

 

Table 3 Issues relating to drivers and pressures identified in each river basin district

 

Issues identified

River basin district

 

 

 

1

 

2

 

3

 

4

 

5

 

6

 

7

 

8

 

Nitrate and phosphorus enriched water

X

X

X

X

X

X

X

X

Organic pollution (CBO5, ammoniacal nitrogen)

X

X

X

X

X

X

X

 

Eutrophication (nitrates, phosphorus, phosphorus compounds, chlorophyll-a, occurrence of algal blooms)

 

 

X

X

X

X

X

X

Microbiological pollution

X

X

X

X

X

X

X

 

Changes in flow regime

X

X

X

 

 

X

X

 

Changes in flora and fauna communities

X

X

X

X

 

X

X

 

Groundwater contamination

X

X

X

 

X

X

X

X

Flooding

X

X

X

X

X

X

 

X

Water scarcity

 

X

X

X

 

X

X

X

Biodiversity reduction

 

 

 

 

 

X

X

X

Metal pollution

 

X

 

 

X

X

X

 

Water quality degradation due to sediment suspension

 

 

 

 

 

X

X

 

Pollution with hazardous and priority substances (biocidal and plant protection products)

 

 

 

X

X

X

X

 

Habitat destruction/fragmentation

 

 

 

 

 

X

X

 

Saline intrusion in groundwater

X

X

 

 

 

 

 

X

Coastal area degradation

X

X

X

X

 

 

 

X

Aquifer overexploitation

 

 

 

 

 

 

 

X

Competition between species for space and food with consequent community disequilibrium

 

 

 

 

 

X

X

 

Inputs from Spain

X

n.a.

X

n.a.

X

n.a.

X

n.a.

Changes in sediment dynamics (erosion and silting up)

X

 

X

X

 

 

 

 

Competition between non-native and indigenous species

 

 

 

 

 

 

 

X

 

 

Figure 5 River basin district in continental Portugal

 

Fig. 5 - River basin district in continental Portugal 

 

RH1 – Minho and Lima

RH2 – Cávado, Ave and Leça

RH3 – Douro

RH4 – Vouga, Mondego, Lis and Ribeiras do Oeste

RH5 – Tejo

RH6 – Sado and Mira

RH7 – Guadiana

RH8 – Ribeiras do Algarve

 

Source: INAG, 2009

 

It should be noted that nitrate and phosphorus enriched water was identified as significant in all RBDs, as was inputs from Spain, which were identified in all international RBDs. Groundwater contamination, flooding, microbiological pollution and organic pollution (CBO5, ammoniacal nitrogen) were identified in seven out of the eight continental RBDs.

  

References

The 2020 outlook

Published: 26 Nov 2010 Modified: 23 Nov 2010

The principal objective of the National Programme for Efficient Water Use (PNUEA), approved in 2005, is to promote the efficient use of water, particularly in the urban, agricultural and industrial sectors, and to help to minimise the risk of water shortages and improve environmental conditions in water environments.

The Programme proposes a range of water-use targets to be achieved by 2015:

a)      Urban consumption target

With total effective urban consumption for 2005 estimated at 330 million m3/year and assuming an effective total demand of 570 million m3/year, water-use efficiency stands at around 60 %. In view of the prospects for controlling losses, user procedures and the technological development of equipment, the aim is to achieve 80 % water-use efficiency by 2015. Because of the country’s geographic and social variability, however, which gives rise to very different situations, this national average is expected to exhibit significant regional or local variations.

b)      Agricultural consumption target

With total effective consumption for 2005 estimated at 3 800 million m3/year and assuming an effective total demand of 6 550 million m3/year, water-use efficiency stands at around 60 %. In view of prospects for the area irrigated, user procedures and the technological development of equipment, the aim is to achieve 65 % water-use efficiency by 2015. Because of the country’s geographic and social variability, which gives rise to very different situations, this national average is expected to exhibit significant regional or local variations.

c)       Industrial consumption target

In analysing efficiency in the use of water for industry, the great variety of processes involved in industrial activity and the technological complexity associated with each process must be borne in mind. Thus despite the uncertainty associated with this analysis, weighted average values can be estimated. With effective consumption for 2005 estimated at 275 million m3/year and assuming an effective total demand of 385 million m3/year, current water-use efficiency stands at around 70 %. In view of the prospects for industrial user procedures and the technological development of equipment, the aim is to achieve 85 % water-use efficiency by 2015.

For the coming years the 2007-2013 Strategic Water Supply and Waste Water Sanitation Plan (Plano Estratégico de Abastecimento de Água e de Saneamento de Águas Residuais [PEAASAR]) provides for regular investment in the renewal and expansion of water supply and sanitation networks and the replacement of equipment. Targets for 2013 include ensuring that around 95 % of the country’s total population has public water supply systems and that around 90 % has public urban wastewater sanitation systems.

The National Strategy for Agricultural and Agro-industrial Waste (Estratégia Nacional para os Efluentes Agro-Pecuários e Agro-Industriais [ENEAPAI]) covering the period from 2007 to 2013 is a key tool for defining and clarifying policy for these sectors and constitutes a strategy for implementing an institutional, management and technical model representing a sustainable alternative for processing waste:

 

•      institutional model for the design, construction and management of waste recovery and treatment solutions [organisations with recognised technical and managerial capacity];

•      collective waste recovery and treatment solutions [technically, economically and environmentally most appropriate solutions];

•      a price structure ensuring the application of the user-pays principle and sustainability [best technical, economic and environmental solutions and optimised management and operating models].

 

A coordinating and monitoring unit, run by the Water Institute (INAG), was set up to implement the ENEAPAI.

For additional information on ENEAPAI

http://www.maotdr.gov.pt/Admin/Files/Documents/ENEAPAI.pdf

 

References

  • MAOTDR, (2007). Estratégia Nacional para os Efluentes Agro-Pecuários e Agro-Industriais. Ministério do Ambiente, do Ordenamento do Território e do Desenvolvimento Regional, Lisboa.

http://portal.min-agricultura.pt/portal/page/portal/MADRP/PT/servicos/Imprensa/nt_xvii/Documentos/01_ENEAPAI.pdf?_template=

Existing and planned responses

Published: 26 Nov 2010 Modified: 23 Nov 2010

One of the objectives of the Water Framework Directive (WFD) is to ensure the sustainable use of water resources in the EU. In accordance with the Directive, Portugal is formulating management plans for each of its 10 river basin districts. These planning tools, brought together in the National Water Plan 2010, which is being drawn up, underpin the management, protection and environmental, social and economic exploitation of water.

For additional information on the application of the Water Framework Directive in Portugal

http://dqa.inag.pt/

 

To reduce nitrate concentrations in water bodies, steps have been taken to implement good agricultural practice by raising farmers’ awareness by means of nationwide training initiatives – especially in areas of greater risk – designed to explain and disseminate environmental techniques and good agricultural practice. The Code of Good Agricultural Practice (Código de Boas Práticas Agrícolas [CBPA]), to be applied voluntarily by farmers, was drawn up to satisfy one of the requirements of the Nitrates Directive. The Code establishes general pointers and guidelines, mainly with a view to helping farmers to take measures to rationalise the use of fertilisers, and a range of growing techniques and methods impacting on nitrogen dynamics in agricultural ecosystems so as to minimise nitrate losses and thus protect surface and groundwater from pollution. It should be noted that the number of holdings that have adopted integrated production systems and organic production methods has increased.

For additional information on good agricultural practices

http://www.drapn.min-agricultura.pt/drapn/zona_v/Files_pdf/CodigoBPA.pdf

 

In the past certain action programmes were approved for vulnerable zones in order to reduce water pollution caused or induced by nitrates from agricultural sources and to prevent further such pollution to protect human health, living resources and aquatic ecosystems and safeguard other legitimate uses of water. A new action programme for vulnerable zones was approved in February 2010 that revises the various programmes already published and makes provision for the creation of new zones.

As regards the water supply and waste water sanitation sector, the Strategic Water Supply and Waste Water Sanitation Plan (Plano Estratégico de Abastecimento de Água e de Saneamento de Águas Residuais [2007-2013]) – PEAASAR II – was approved in 2007 to ensure the continuity of the water sector strategy set out by the previous PEAASAR (2000-2006), which played an essential role in structuring the water supply and sanitation sector.

For additional information on PEAASAR II

http://www.maotdr.gov.pt/Admin/Files/Documents/PEAASAR.pdf

 

To monitor compliance with the principal objectives and measures provided for in the national water plan (Decree-Law No. 112/2002 of 17 April) and to characterise the country’s water supply, drainage and wastewater treatment sectors, the National Water Supply and Waste Water System Inventory (Inventário Nacional de Sistemas de Abastecimento de Água e de Águas Residuais [INSAAR]) was developed and also operates as an instrument for monitoring and assessing PEAASAR II (2007-2013).

For additional information on INSAAR

http://insaar.inag.pt  

 

The Alqueva dam, whose reservoir is considered to be Europe's largest artificial lake, was built in the Alentejo to establish a strategic water reserve to supply agricultural, urban and industrial areas in a vast part of the region. This strategic reserve will allow water to be used even in periods of prolonged drought, since the Alentejo is characterised by its irregular water resources and climate – very hot dry summers, cold and sometimes rainy winters. Its principal feature, however, is that rainfall is concentrated in a short period of the year, normally from November to February, and with equally irregular cycles: periods of drought may last for three or more consecutive years.

For additional information on dams in Portugal

http://cnpgb.inag.pt/gr_barragens/gbportugal/index.htm

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The country assessments are the sole responsibility of the EEA member and cooperating countries supported by the EEA through guidance, translation and editing.

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