State of Surface and Groundwater Bodies

The "State of Surface and Groundwater Bodies" fact sheet analyses the ecological and chemical status of surface water and the quantitative and chemical status of groundwater.

The Water Framework Directive (WFD), transposed into the national legal system by the Water Law, as amended and republished by Decree-Law no. 130/2012and by complementary legislation, establishes the framework for sustainable water management, highlighting the main environmental goal of achieving a "Good" status for all surface water and ground water bodies.

Within the scope of the 2nd planning cycle (River Basin District Management Plans – PGRH 2016-2021), the classification of the state of the water bodies, as determined in the 1st planning cycle (PGRH 2009-2015) was re-evaluated for the eight River Basin Districts (RHs) in mainland Portugal:

  • RH1 - River Basin District of Minho e Lima;
  • RH2 - River Basin District of Cávado, Ave e Leça;
  • RH3 - River Basin District of Douro;
  • RH4 - River Basin District of Vouga, Mondego e Lis;
  • RH5 - River Basin District of Tejo e Ribeiras do Oeste;
  • RH6 - River Basin District of Sado e Mira;
  • RH7 - River Basin District of Guadiana;
  • RH8 - River Basin District of Ribeiras do Algarve.

In the case of surface waters, including inland surface waters (rivers and reservoirs), transitional waters and coastal waters, the assessment of the overall state of water bodies’ results from the combination of their ecological status/potential and their chemical status.

The ecological status reflects the quality of the structure and functioning of the aquatic ecosystems associated with surface water and is expressed on the basis of its deviation from the conditions of an identical body of water, i.e., one of the same type, under baseline conditions. Baseline conditions correspond to a state in which anthropogenic pressures are not that significant and where only minor physico-chemical, hydromorphological and biological changes occur.

The evaluation of the ecological status takes into account several quality elements: biological elements, general physico-chemical elements, specific pollutants and hydromorphological elements (supporting biological elements). The final ecological status classification is given based on the worst classification obtained for each quality element.

For heavily modified and artificial bodies of water, the concept of ecological status is replaced with another concept: the ecological potential. The ecological potential is expressed as the deviation from the "maximum ecological potential," which represents the biological and physico-chemical conditions in which the only impacts on the body of water result from its artificial or heavily modified characteristics, after the implementation of all mitigation measures that do not significantly affect its use or the surrounding environment.

As for the chemical status, its assessment focuses on compliance with the environmental quality standards (EQS) for priority substances and other pollutants defined in the context of the water policy listed in the Priority Substances Directive (as amended by Diretive no. 2013/39/EU), which was transposed into the national legal system (Decree-Law 103/2010as amended and republished by Decree-Law no. 218/2015). The EQS defined for priority substances and other pollutants are, therefore, the basis for assessing the chemical status of surface waters; i.e., in order for a surface water body to achieve a 'Good' chemical status, it is necessary that concentrations of priority substances and other pollutants comply with the respective EQS.

In this context, it should be clarified that only the chemical parameters listed in national legislation are considered when assessing the chemical status of surface waters. General physico-chemical elements (supporting biological elements), such as total phosphorus, as well as specific pollutants (defined in the PGRH) are considered when assessing the ecological status of surface water bodies.

In turn, the global assessment of the status of groundwater bodies involves the assessment of both their chemical and quantitative statuses.

The assessment of the quantitative status is governed by the Decree no. 1115/2009, which approves the regulation for evaluating and monitoring the quantitative status of groundwater bodies, and follows the procedures defined in the “Guidance on Groundwater Status and Trend Assessment” guide (prepared by the Working Party on Groundwater, within the framework of the Common Implementation Strategy for the WFD).

With regard to the chemical status, the procedures for its assessment are set out in Directive 2006/118/EC, which was transposed into national law by Decree-Law no. 208/2008, on the protection of groundwater against pollution and deterioration. These assessment procedures are also in line with the “Guidance on Groundwater Status and Trend Assessment”.

The environmental goals set out in the WFD are intended to ensure a 'Good' status for water bodies by 2015, while allowing for some exceptional situations where environmental targets may be extended or derogated in order to ensure that they are achieved in a balanced way, considering, among other aspects, the feasibility of the measures to be implemented, the technical and scientific work to be carried out, the effectiveness of those measures and the operating costs involved.

The environmental target established for surface water bodies consists of achieving a 'Good' state when both the ecological and chemical state are classified as 'Good.' In the case of bodies of water identified and designated as heavily modified or artificial bodies of water, the environmental goal is only achieved when the ecological potential and the chemical status are classified as 'Good.'

As for groundwater bodies, the environmental target is to achieve an overall 'Good' status, which is when both its chemical and quantitative status are 'Good.'

This fact sheet concerns mainland Portugal and shall be updated every six years.


Objectives and targets: 
  • To have classification systems in place for all (relevant) quality elements, for the various types and categories of water bodies;
  • The status of a significant number of bodies of water (between 60% and 70%) shall be determined via monitoring, and the rest can be determined indirectly through modelling or grouping;
  • To meet the environmental goals for 77% of water bodies in 2021 and for 100% in 2027.


Progress analysis:

Given that two PGRH cycles have been conducted, it is possible to compare the classification of the global status of surface water bodies between the 1st and 2nd planning cycles, for the eight River Basin Districts (RH) of mainland Portugal.


Last update: 
Monday, 5 June, 2017