Bathing Waters

The fact sheet “Bathing Waters” assesses the quality of bathing waters and tallies the number of beaches and marinas in Portugal that were awarded the “Blue Flag”. 


Surface waters, whether inland, coastal or transitional, where a large number of people are expected to bathe and where bathing has not been permanently prohibited or advised against, are considered bathing waters. The quality of bathing waters is a subject of great relevance, as it is considered a good indicator of the environmental quality and potential for tourism development, besides being a determining factor in terms of public health.

The assessment of the quality of bathing waters is governed by the criteria set out in  Directive 2006/7/EC, and in Decree-Law no. 113/2012. The assessment is carried out based on a bacteriological analysis for the identification of intestinal Enterococci and Escherichia Coli. In addition, where the bathing water profile shows a trend towards the proliferation of cyanobacteria, macroalgae and/or marine phytoplankton, it must be ascertained whether its presence is acceptable, what are the associated health risks and the appropriate management measures to be taken, including informing the public. Within the framework of monitoring programs, bathing waters must also be visually inspected to detect pollution from tar, glass, plastic, rubber and other waste.

Depending on the results of bacteriological analyses for intestinal Enterococci and Escherichia coli, bathing waters are classified as 'Excellent,' 'Good,' 'Acceptable' or 'Poor'.

In general cases, a minimum of 16 samples is required to issue quality classifications for the four bathing seasons (minimum of four samples per bathing season). That is to say, in the 2018 bathing season, and for general cases, the classification of bathing waters is based on at least 16 samples for the years 2017, 2017, 2016 and 2015.

For new bathing waters, or those that have undergone changes to improve quality, classification may be carried out as soon as the 16 samples are obtained, which may occur as early as the first bathing season or up to the fourth subsequent bathing season. In this regard, until the 16 samples are obtained, new bathing waters or waters that have undergone quality improvement measures are considered 'unclassified,' but are nevertheless monitored throughout the bathing season.

At the same time, the Blue Flag programme aims at educating the public on the sustainability of marine biodiversity and of the coastal and lacustrine areas, as well as encourage the adoption of sustainable behaviours that respect Nature. In this regard, the Blue Flag is an environmental award, which, every year, is awarded to the beaches, marinas and recreational ports that meet a set of criteria related to environmental management, environmental education, information, bathing water quality, services and user safety.

This fact sheet concerns mainland Portugal and the Autonomous Regions of Madeira and the Azores and shall be updated on an annual basis anualmente.

Objectives and targets: 
  • O Decree-Law no. 135/2009, as amended and republished by Decree-Law no. 113/2012, que transpôs a Directive 2006/7/EC of the European Parliament and of the Council, sets out the goal of increasing the number of bathing waters classified as 'excellent' or 'good,' and the target of ensuring that all bathing waters have the conditions to be classified, at least as 'Acceptable' by the end of the 2015 bathing season.
Progress analysis:

The number of bathing waters identified, mandatorily subjected to water quality control for bathing, has grown considerably over the last decade, going from 514 in 2011 to 608 in 2018. Of the latter, 480 (79%) are coastal or transitional bathing waters and 128 (21%) are inland bathing waters.

Of the 608 bathing waters identified in 2018, 554 (91.1%) presented 'excellent' quality, 9 (1.5%) 'acceptable' quality and 2 (0.3%) were classified as "poor" quality. It should be noted that 14 waters were considered 'unclassified' (were monitored, do not yet have the required 16 samples), which correspond to 2.3% of all bathing identified waters.

Last update: 
Friday, 17 May, 2019