Sustainable development​
in Pays d’Opale

Framed by French and European regulations on water, aquatic environments and the environment, the missions of GEMAPI are described in 4 paragraphs of article L.211-7 of the environment code:

→ Develop a watershed or a fraction of a watershed, in particular storage devices in reservoir lakes,

→ Maintain and develop a watercourse, canal, lake or body of water, for reasons of emergency or general interest, in particular in the event of generalized deficiency of riparian owners,

→ Provide protection against floods, in particular by building and managing dykes,

→ Protect and restore sites, aquatic ecosystems and wetlands, as well as riparian woodlands, including the restoration of ecological continuities.

The municipalities of the CCPO have chosen to add to the community competences:

→ The fight against runoff and soil erosion, the management of mudslides.

The community of municipalities determines the missions it exercises
directly on its own and those it entrusts to other organizations to deal with water-related issues (runoff, erosion, flooding, water quality, etc.).

At a coherent hydrographic scale which is that of the catchment area to manage GEMAPI issues, the CCPO can in fact transfer or delegate all or part of the competence to joint common law or specialized syndicates – * EPAGE or **EPTB .

Decisions on carrying out studies, works or actions are then taken by the competent structure.

A watershed is a portion of territory delimited by ridge lines (or watershed lines) and irrigated by the same hydrographic network (a river, with all its tributaries and all the watercourses that feed this territory).

Within the same watershed, all the water received is concentrated towards the same exit point called the outlet.
Soil erosion is a natural phenomenon that results from the ablation of the surface layers of the soil and the movement of materials along it.
component. It lowers the productivity of the land and contributes to the pollution of adjacent streams, wetlands and lakes.

* EPAGE: Public Water Development and Management Establishments
** EPTB: Public Territorial Basin Establishments

The territory of the Community of Communes Pays d’Opale is divided according to the watersheds and their various issues and challenges. Mixed syndicates manage aquatic environments and flood prevention to varying degrees depending on the specificities of each.

Initially created following the many floods that the watersheds experienced, the mixed syndicates have diversified to integrate the management of aquatic environments. Two of them have a Water Development and Management Plan: the SAGE.

The SAGE is developed collectively by the water stakeholders of the territory grouped within a deliberative assembly, the Local Water Commission (CLE).

Mixed syndicates support and/or implement Action and Flood Prevention Programs: the PAPI, which promote integrated risk management with a view to reducing the harmful consequences of floods on human health, property, activities economic and the environment.

SYMSAGEB: Joint Syndicate for the SAGE of Boulonnais – SAGE and PAPI of Boulonnais
SYMVAHEM: Mixed Syndicate of the HEM Valley – PAPI of the HEM
PMCO: Metropolitan pole of the Opal Coast – SAGE and PAPI of
Aa Delta
IIW: Intermunicipal Institution of Wateringues
Do not confuse the Institution Intercommunale des Wateringues with the sections of the wateringues (associations of owners, organized into administrative commissions). These latter are not
financed within the framework of the GEMAPI.

The SYMSAGEB and the SYMVAHEM manage all of the GEMAPI skills as well as the fight against runoff and soil erosion on their territory.

On the territory of the foothills and the maritime plain, several actors are called upon to manage competence.

The IIW thus ensures from Sangatte to the Belgian border the mission of evacuation of water from the polder to the sea, according to the tides, by five gates of locks, as well as the hydraulic protection by pumping of this maritime plain representing 85,000 hectares. The IIW is also carrying out studies on the canals which are no longer navigable with a view to extending its powers over them (VNF manages the navigable canals). It is currently in the process of revising its statutes to also include the management of aquatic environments.

The CCPO works with many partners according to their areas of responsibility such as the GDON which organizes the fight against the muskrat, the CEN (Conservatoire des Espaces Naturels) for the management of wetlands (Pont sans Pareil) and even EDEN 62 which is a Mixed Syndicate, in which elected members of the Board are represented
county and local authorities. Eden 62 manages Sensitive Natural Areas (ENS).

All the mixed syndicates as well as the CCPO favor consultation with all the actors who are called upon to intervene: watering associations, public and private owners, farmers, infrastructure managers, etc.

At the CCPO, the unions and players in the territory carry out concerted management of water and aquatic environments at the level of their catchment area and their areas of expertise. Actions are undertaken within the framework of SAGEs and PAPIs and generally require several steps before they are implemented. Preliminary studies before carrying out the work are often necessary to have a reliable project that complies with regulations.

CCPO

It monitors the missions of the various unions by appointing representatives to the various union committees. The technicians are also associated with the studies and works carried out.

An ARARAT 2 program including more structuring works (retention basin – step ditches) is under study on the 4 vents basin and the Andres funds. A third ARARAT 3 project, aiming to carry out a new soft hydraulics development program, is under study to cover the entire territory of the foot of the hills, in particular on the Ardrésis.

The CCPO has entrusted the Conservatoire des Espaces Naturels (CEN) with the management of the natural site of the Unparalleled Bridge, a wetland located in the municipality of Ardres. This site is of ecological interest and contributes to the ecological continuity with the regional nature reserve of Pont d’Ardres.

The GEMAPI competence is transferred to the following other pools: The SYMVAHEM, the SYMSAGEB, the IIW

EDEN 62

Eden 62 manages 3 wetlands on CCPO territory. The actions undertaken include: the development of a management plan, the maintenance of the sites, the reception of the public and the animation for the discovery of the natural heritage.

The Sensitive Natural Space of the “Communal d’Hardinghen” is a wet meadow bordered by hedges and woods, dotted with small depressions, with the presence of two ponds and two groves. It is located and belongs to the Municipality of Hardinghen. It has an area of ​​13 ha, 10 ha of which are included in the 2011-2036 provision agreement. A Management Plan is drawn up for the Period 2012-2021 (8 ᵉᵐᵉ year of implementation). The current challenges of the site are the vegetation and the species developing within the aquatic and amphibious environments, as well as the species taking advantage of the network of hedges and the presence of riparian afforestation.

The Sensitive Natural Area of ​​the “Marais du Calaisis” is a vast marshy basin traversed by multiple channels and punctuated by old peat pits, which allowed the development of aquatic, amphibious and hydrophilic vegetation under these different stages of maturation. It is made up of two Sensitive Natural Areas, that of the “Marais de Guînes” and that of the “Lac d’Ardres”.

It is located in the municipalities of Andres and Guînes, it belongs to the Department of Pas-de-Calais. Its Surface represents 14 ha (No acquisition in 2019). The Sensitive Natural Area of ​​”Lac d’Ardres” is the property of the Department of Pas-de-Calais and covers 163 ha. Vegetation and species developing within the different stages of evolution of aquatic, amphibious and hydrophilic environments are the main challenges of the site.

When the earth comes loose under the action of rain and runoff, this phenomenon is called water erosion of the soil. It can form mudslides.

Runoff and mudslides can impact homes, roads, waterways or canals.
This phenomenon impoverishes agricultural plots since the most fertile part of the soil is uprooted.

The CCPO, a sensitive territory?

Protection against erosion is an issue for the CCPO and concerns the preservation of the agronomic quality of agricultural soils, carbon storage, improvement of the quality of wetlands and waterways.