FAQ – Practical information for getting to the Audomarois marsh and visiting its rivers

Yes, there are maps of the Audomarois Marsh. Here are some options for finding maps:

IGNrando – The IGNrando site offers a map for a hike to discover the Audomarois marsh. Note that Saint-Omer and its marsh are spread over 3 or even 4 paper IGN maps. The online site allows you to compose your own topographic map. Another option: use the application.

The official navigation map of the marsh: The Saint-Omer tourist office and the urban area regularly publish a nautical map indicating the areas of interest, the node points and other useful information on the marsh. This map, worth €4, is waterproof and tear-proof.

The applications maps, visiorando, etc… provide excellent plans of the marsh. Geolocated, what’s more. But note that in a canoe, a paper plan is much safer.

The Audomarois marsh, particularly Saint-Omer, is accessible by several means of transport:

Main road axes

A26 motorway: From Calais (40 minutes) and Reims (2h25)

A16 motorway: From Dunkirk (47 minutes)

A25 motorway: From Lille (1 hour)

departmental

• D928: From Boulogne-sur-Mer
• D300: From Le Touquet
• D942: From Arras and Lens

Public transport

Regional bus lines

• Line 904: Serves Saint-Omer, Longuenesse, Saint-Momelin, Serques, Watten, Holque, Saint-Pierre-Brouck, Cappelle-Brouck, Bourbourgs, Petite-Synthe, Dunkirk.
• Line 923S: Connects Millam, Merckeghem, Volckerinckhove, Lederzeele, Nieurlet and Saint-Momelin and Longuenesse to Saint-Omer

Internal bus lines (Mouvéo network)

• Line 1: Serves Saint-Omer and Longuenesse
• Line 2: Connects Saint-Omer, Longuenesse, Arques, Blendecques, Helfaut, Wizernes and Hallines
• Line 3: Serves Saint-Omer, Longuenesse and Arques
• Line 4: Connects Saint-Omer, Saint-Martin-Lez-Tatinghem and Longuenesse
• Line 5: Serves Saint-Omer, Saint-Martin-Lez-Tatinghem and Clairmarais
• Line 6: Connects Saint-Omer, Longuenesse, Arques and Blendecques

Getting to Saint-Omer by train

Saint-Omer station is served by the TER Lille –Calais line.

Cycling

EuroVelo 5 passes close to Saint-Omer, offering a cycling option for cyclists.

Yes, it is possible to visit the Audomarois marsh with a dog. Most of the structures offering guided tours of the marsh accept dogs. This is particularly the case for the Faiseurs de Bateaux. However, each one has its own rules. Dogs must be kept on a leash. A limited number of animals can be set per boat. Fighting dogs, even on a leash and muzzled, are, for their part, very often prohibited.

Please note that specific restrictions may be in place within the Nature Reserve. In principle, only assistance dogs are allowed in the reserve.

Unfortunately, yes, the Audomarois marsh is frequently subject to flooding. This territory is particularly exposed to flooding phenomena due to its nature as a wetland. Several major events have marked the recent history of the marsh:

• March 2002: Very significant flood with flooding of a good number of houses. This date was considered a reference point until 2023.
• November 2009: Significant flooding. Many fields flooded, some houses threatened.
• October 2012: Another notable flood episode with further impact on the land.
• November 2023 and January 2024: Two successive flood episodes, with water levels reaching one meter in four days. This is a historic flood with levels not reached since 1894.

The causes of these floods are multiple:

• Heavy and continuous rains for weeks
• Runoff facilitated by the removal of numerous hedgerows and concreting.
• Saturation of hydraulic networks
• Basin-shaped marsh located downstream of the Aa sauvage
• Limited evacuation capabilities to the sea
• Complex management of the canal network.

The Audomarois marsh acts as a vast buffer zone during floods, extending over a watershed of approximately 630 km². This complex hydraulic configuration makes the territory particularly vulnerable to flooding, which has led to the establishment of a Flood Risk Prevention Plan (PPRi) for 12 municipalities in the region.

Contrary to what one might think, mosquitoes do not cause too many problems in the Audomarois marsh because the water there is not stagnant.

Here are also other reasons why mosquitoes do not cause too much trouble in the Audomarois marsh:

• The presence of rich biodiversity, including natural mosquito predators such as bats, birds and dragonflies, helps control their population.
• The marsh benefits from a particular microclimate with high humidity and moderate temperatures, which can influence the life cycle of mosquitoes.
• The variety of habitats in the marsh, including reed beds and maintained meadows, provides a diverse environment that does not necessarily encourage the proliferation of mosquitoes.
• Seasonal fluctuations in water levels, including periodic flooding, can disrupt mosquito breeding sites.

The best time to visit the Audomarois marshes depends on what you are looking for.

Spring: It is a time of rebirth when the fauna and flora awaken, offering a vibrant spectacle of life and colors. The boat trips are particularly magical with fresh vegetation and animals that begin to animate the landscape again. The season allows you to observe birds nesting in the banks.

Summer: It is the apotheosis with a perfect temperature and lush vegetation. It is the ideal time for long boat trips and to enjoy the sun.

Autumn: The marshes are transformed with shimmering colors. It is a quieter time, perfect for those looking to avoid the summer crowds. It is also a good season for observing migratory birds.

Winter: The marshes turn into a haven of peace with a mystical atmosphere. This is the ideal time for an intimate visit and to observe the simple beauty of the marshes.

The peak tourist season runs from April to October. From June to October, it is the peak cauliflower season in the Audomarois marsh.

Yes, since 2019, the Audomarois marsh has been equipped with signage similar to the node point system. Each intersection has a post stuck on the edge, topped with a box. This box has a sign indicating, on the front, a number (node ​​point) and the name of the canal or ditch on which you are traveling. On the left and right side, another sign tells you the name of the next river.

This is a code to communicate to the firefighters in the event of an emergency so that the emergency services can easily locate you in the marsh.