Guicking et al. (2002, 2008) found three different genetic groups within Natrix maura: one in Europe (with a "possible fourth lineage" in southern Spain); one in Morocco; and one in Tunisia (including the introduced population in Sardinia).

European regional assessment: Least Concern (LC)
EU 27 regional assessment: Least Concern (LC)

The species is assessed as Least Concern for both Europe and the EU27 Member States in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a threatened category.

In Europe, this species ranges from Portugal and Spain through much of France, to extreme southwestern Switzerland and northwestern Italy (Speybroeck et al. 2016). Its northern limit lies just north of the Loire Valley (Speybroeck et al. 2016). Introduced subpopulations are known from Menorca and Mallorca in the Belearic Islands (Spain) (Speybroeck et al. 2019). The origin of remaining European island subpopulations - known from Sardinia (Italy), Corsica and Iles d'Hyéres (France) is unclear (Solarz 2019), although Speybroeck et al. (2016) considers it introduced in Sardinia and Corsica. Genetic evidence from the Sardinian subpopulation indicates a likely human-mediated introduction by the Romans or Carthaginians (Solarz 2019). It was last recorded on Corsica - where it was known from three individuals reported from two localities - in 1985, and no established population has ever been confirmed from this island (Solarz 2019). A released individual has been recorded from Belgium, but there is no evidence of an introduced population (Solarz 2019). It is found in the Spanish North African territories Ceuta and Melilla (Fahd et al. 2002). The species can be found from sea level up to 2,600 m asl.

Outside the European region, the range of this species extends to North Africa, where it is present in most of Morocco, northern Algeria, northern and central Tunisia (and the offshore island La Galite) and northwestern Libya.

In most of its range it is a common species. The development of canals and rice fields has resulted in high population densities in parts of the southern Mediterranean due to increases in the populations of prey species (Santos et al. 2000). In the Ebro Delta densities of 0.93 individuals /ha were recorded in 1995 and the species was found in nearly 50% of one-hectare survey sites (Santos and Llorente 2009). A 2008 survey using the same methodology recorded no snakes at these sites, although they were still present in rice fields in the surrounding area close to natural lagoons and native vegetation. This suggests a strong decline in this intensively-farmed area has taken in the intervening period (Santos and Llorente 2009). A subsequent study modelling population trends based on citizen science data collected between 1980 and 2017 (Spain) and 1980 and 2018 (Languedoc, France) found was broadly stable in Spain and declined by 54.9% in southern France over this period, corresponding to declines of 23.22% in Languedoc over a presumed three generation period of 16.5 years (Santos et al. 2022).

This species is highly aquatic and is "nearly always" found close to, or within, waterbodies such as rivers, canals, lakes and ponds, generally favouring larger waterbodies than the grass snake where the two species co-occur (Speybroeck et al. 2016). These are often found in meadows and open woodlands. It has also been recorded from areas of brackish water, including coastal marshes (Speybroeck et al. 2016). It is active by both day and night in most of its range, but can be almost fully nocturnal in the south during the hottest parts of the year (Speybroeck et al. 2016). The species lays between three and 20 eggs (typically "about seven" - Speybroeck et al. 2016). It has an assumed generation length of 5.5 years (Santos et al. 2022), inferred by these authors to be a year later than age at maturity.

While this common and adaptable species is not significantly threatened across its range as a whole it is exposed in parts of its range to aquatic pollution. It is threatened in Switzerland, and presumably other parts of the species' range, by channelization of rivers and other waterbodies. As with many snake species, individual animals are occasionally killed by people, as they are often confused with venomous vipers. Santos and Llorente (2009) hypothesize that the decline they report in the Ebro Delta is likely to be attributable to some combination of the impacts of habitat transformation (such as the replacement of irrigation canals with cement ducts), agricultural intensification of the rice fields resulting in a heavy pollutant load and mechanical clearance of vegetation used as shelter sites, a documented decline in the frogs on which the snake preys, and an increase in the abundance of natural predators favoured by the environmental changes, particularly herons. In this area the species appears to be reliant on remnant natural areas for its persistence (Santos and Llorente 2009). In particular, this species is known to accumulate organic pollutants in its body and lacks mechanisms to excrete them, which may have negative impacts on its survival and reproductive success (Santos and Llorente 1999 and refs therein).

This species is not popular as a pet, but is occasionally kept by hobbyists in Europe (Solarz 2019).

This species is listed on Annex III of the Bern Convention, and is protected by national legislation in Switzerland. It is present in many protected areas. This species is categorised as Critically Endangered in Switzerland (Monney and Meyer 2005). Population monitoring is recommended in parts of the range where declines have been recorded. It is considered likely that successful introductions could occur throughout the European Union mediated primarily by the trade in olive trees, with the potential to become invasive in Mediterranean islands and other areas of high conservation value (Solarz 2019). It is a significant invasive in Mallorca, as a predator of the Mallorcan midwife toad which now survives mainly in areas climatically unsuitable for the snake (Solarz 2019). Quarantine procedures to prevent wider introduction of this snake should include the use of baited traps at quarantine facilities and limiting the import of suitable shelter trees during the snake's hibernation and oviposition periods, and efforts to eradicate and prevent the spread of established populations should be implemented (Solarz 2019).