1. General information
Location and description of the intervention
City or FUA
Marseille (FUA)
Region
Europe
Native title of the NBS intervention
Cinq nouveaux bassins de rétention des eaux pluviales
Short description of the intervention
In 2014, the Marseille Provence Métropole Urban Community commissioned five new stormwater retention basins in order to preserve the quality of coastal waters and reduce the risk of flooding (Ref. 4). In the past, in the event of severe thunderstorms the sewage networks became saturated and a portion of the water was then directly discharged into the sea without going through the sewage treatment plants (Ref. 1). This is seen as "one of the most important documents of recent years in terms of environmental protection. It foresees in the next 5 years, 185 million euros of major works" (Ref. 1).
Address

5 different areas: Station d'épuration Geolide, Saint-Mauront, Cours Pierre Puget , rue Melchior Guinot , place Jules Guesde
13000 Marseille
France

Location
The NBS is a city-wide initiative, the GIS point marks the centre of the city
Type of area before implementation of the NBS
Other
Please specify “other type of area” before implementation of the NBS
This is a city-wide initiative (Ref. 1).
Website of the intervention
http://www.marseille-provence.fr/index.php/competences/eau-et-domaine-public/as…
Timeline of intervention
Start date of the intervention (planning process)
unknown
Start date of intervention (implementation process)
2014
End date of the intervention
2018
Present stage of the intervention
Ongoing
Please specify "other" stage of the intervention
"25 operations will be carried out according to a very precise schedule for the period 2014-2018" (Ref. 1)
Goals of the intervention
-"The construction of 5 retention basins will allow to regulate the rain water and to reduce the pollution rate too important" (Ref. 1)
-Avoid runoff water ending in the ocean and prevent people to swim due to pollution (Ref. 1 and 2)
-Preserve the habitat of the aquatic life and their environment (access to food) (Ref. 1)
-Health, Tourism and Economic value (Ref. 2)
-"Preserving the receiving marine environments and revitalizing them at the outlet of the outfall in the calanque de Cortiou, such are the ambitions of the Aix Marseille Provence metropolis across the Ganay basin. Coupled with SUEZ's dynamic rainwater management solutions, it will prevent the discharge of 1 million m3 of untreated wastewater into the Calanques National Park each year. A reduction of 50% compared to the current situation" (Ref. 6).
Quantitative targets
"The creation of 5 water retention basins that will represent 127 000 m3:
-50,000 m3 at the entrance of the wastewater treatment plant
-12,000 m3 place Jules Guesde
-17,000 m3 in the former Lajout railway tunnel under the street Melchior Guinot
-15,000 m3 Place Pierre Puget
-33,000 m3 in Saint-Mauront" (Ref. 1)
"Creation of 5 rainwater retention basins on the unit network with a storage capacity that will be multiplied by 10." (Ref. 2)

-(Ref. 4) Basin characteristics of Pierre Puget unit water retention basin:
of 15,000 m3
100 m in length
10 m wide
diaphragm wall 30 m deep
12.7 m3 / s feed rate
Monitoring indicators defined
Volume of water retained and treated (m^3)
Inhabitants served by system
Hecatres served by system (Ref. 2)
Length of basins (m)
Width of basins (m)
Depth of diaphragm walls (m)
Feed rate (m^3/s)
Sustainability challenge(s) addressed
Water management (SDG 6)
Flood protection
Stormwater and rainfall management and storage
Improvements to water quality
Coastal resilience and marine protection (SDG 14)
Coastal protection / hazard mitigation
Marine and coastal biodiversity protection
Green space, habitats and biodiversity (SDG 15)
Habitat and biodiversity conservation
Environmental quality
Waste management
Health and well-being (SDG 3)
Creation of opportunities for recreation
Economic development and employment (SDG 8)
Tourism support
Employment/job creation
Habitats and biodiversity conservation: What types of conservation goals are / were defined for the NBS intervention?
Ecosystem-focused
Habitats and biodiversity conservation: What activities are implemented to realize the conservation goals and targets?
Protect and enhance urban habitats
Preserve and strengthen existing habitats and ecosystems
Reduce negative impacts and avoid the alteration/damage of ecosystem
Protect species
Undertake specific measures to protect species
Implementation activities
"25 operations will be carried out according to a very precise schedule for the period 2014-2018" (Ref. 1)
-Restructuring of the Collector Sud Littoral, and the collectors of the Olives avenue and the Rose avenue. These two operations are important for the protection of bathing water quality.
-Securing and rehabilitating several lifting and collecting stations.
-Modernization of the control system of the sanitation system with the installation of new sensors and real-time modeling.
-Closure of the washing boxes and the installation of greywater pumps in the ports of the territory.
-Actions to preserve or reconquer the natural environment with the setting up of coastal and water-warning stations, measures to promote the progression of cystoseireal algae (providing shelters and food for numerous coastal fish species) in Cortiou, creating shelters for fish in the ports.
-Realization of a set of fundamental studies to guarantee the future evolution of the sanitation system (Ref. 1)
-"In order to preserve the quality of coastal waters and reduce the risk of flooding, the Marseille Provence Métropole Urban Community is implementing a program to modernize the unit network. The project notably includes the construction of a retention basin at the level of Cours Pierre Puget" from 2016-2022 (Ref. 4).
Type of NBS project
Coastal landscape management or protection
NBS domain and interventions
Ecological domain(s) where the NBS intervention(s) is/are implemented
Blue infrastructure
Coastlines
Green areas for water management
Sustainable urban drainage systems
What is the level of innovation / development of the NBS related to water management?
Medium / High: sustainable urban drainage systems which include water storage and diverts water flooding
Vegetation Type
Other
Amenities offered by the NBS
Unknown
Services
Expected ecosystem services delivered
Regulating services
Coastal protection
Flood regulation
Water purification / filtration
Other
Habitat and supporting services
Habitats for species
Cultural services
Tourism
Recreation
Mental and physical health and wellbeing
Please specify "other regulating service"
pollution clean up: "The construction of 5 retention basins will allow to regulate the rain water and to reduce the pollution rate" (Ref. 1).
Scale
Spatial scale
Meso-scale: Regional, metropolitan and urban level
Beneficiaries
Primary Beneficiaries
National-level government
Local government/Municipality
Citizens or community groups
Please specify other local relevant strategy
Waste water treatment plan: "Objectives of the Agglomeration Contract signed in July 2014 to improve the performance of wastewater treatment in the city and the quality of coastal waters and urban rivers." (Ref. 1 and 3)
Governance
Governance arrangements
Co-governance with government and non-government actors
Non-government actors
Private sector/Corporate/Business
Please specify the roles of the specific government and non-government actor groups involved in the initiative
-"In order to preserve the quality of coastal waters and reduce the risk of flooding, the Marseille Provence Métropole Urban Community is implementing a program to modernize the unit network. The project notably includes the construction of a retention basin at the level of Cours Pierre Puget" from 2016-2022 (Ref. 4).
-€ 185.6 million for the next five years to be financed by MPM (Marseille Provence Métropole), the Seram (Marseille Sewerage Network Operations Company) within the framework of the Public Service Delegation (DSP) and the Water Agency. "In the framework of the DSP, Seram will build a 50,000 m3 storage basin near Géolide. MPM (Marseille Provence Métropole) will be the contracting authority for the creation of the 4 additional basins" (Ref. 2)
The French State is also involved in this project because it is mentioned that "An agglomeration contract signed for the improvement of the sanitation system and the quality of the aquatic environment between the State, MPM and the Water Agency" (Ref. 2) and "The State undertakes to assist the community in carrying out this program" (Ref. 4, page 9). "An agglomeration contract with the Rhône, Méditerranée and Corsica Water Agency was signed. Its objective is to improve the functioning of the sanitation system of the Marseilles conurbation and the quality of its aquatic environments" (Ref. 1). Partners in this project are the local actor Marseille Provence Metropole (Ref. 1).
Key actors - initiating organization
Local government/municipality
Public sector institution
Land owners
Public space owned by the city
Key actors - Other stakeholders involved (besides initiating actors)
EU body
National government
Regional government
Local government/municipality
Public sector institution
Private sector/corporate actor/company
Citizens or community group
Land owners
Public space owned by the city
Participatory methods/forms of community involvement used
Unknown
Policy drivers
NBS intervention implemented in response to an Regional Directive/Strategy
Yes
Please specify the "Regional Directive/Strategy"
"To achieve the objectives set by the State and by Europe, MPM (Marseille Provence Metropole) has put in place a program of large-scale work""Meet the new requirements imposed by the European directives on "Water and the marine environment" and "Urban waste water" as well as the new regulatory framework imposed by the State." (Ref. 2)
"the Urban Community has made great efforts to comply with the new European Directives by 2017" (Ref. 1)
NBS intervention implemented in response to a national regulations/strategy/plan
Yes
Please specify the national regulations/strategy/plan
"To achieve the objectives set by the State and by Europe, MPM (Marseille Provence Metropole) has put in place a program of large-scale work"."Meet the new requirements imposed by the European directives on "Water and the marine environment" and "Urban waste water" as well as the new regulatory framework imposed by the State." (Ref. 2)
NBS intervention implemented in response to a local regulation/strategy/plan
Yes
Please specify the "local regulation/strategy/plan"
"Objectives of the Agglomeration Contract signed in July 2014 to improve the performance of wastewater treatment in the city and the quality of coastal waters and urban rivers." (Ref. 1 and 3)
Mandatory or voluntary intervention
Mandatory (based on policy)
Intervention is mandatory
Spatial planning guidance
Spatial planning law
Environmental regulation
Enablers
Presence of specific city-level GI/NBS vision/strategy/plan - mentioned in connection to the project
Yes
Please specify
"In order to preserve the quality of coastal waters and reduce the risk of flooding, the Communauté Urbaine Marseille Provence Métropole implements a modernization program for the unit network" (Ref. 4)
"Since its creation, Marseille Provence Métropole has ensured a continuous effort to modernize and maintain the sanitation systems under its control and in particular in the territory of its member municipalities located on the perimeter of the agglomeration of sanitation from Marseille. This effort resulted in major renovations of the Geolide treatment plant between 2004 and 2008, with the implementation of a biological treatment plant." (Ref. 5, page 3)
Presence of specific city-level GI/NBS section/part in a more general plan - mentioned in connection to the project
Unknown
If there is a relevant strategy or plan, please specify the theme / type of the plan.
Water regulation strategy
General municipal plan
Other
Please specify other vegetation type
five new stormwater retention basins (Ref. 4).
Presence of city network or regional partnerships focused on NBS - mentioned in connection to the project
Yes
Please specify
"An agglomeration contract with the Rhône, Méditerranée and Corsica Water Agency was signed. Its objective is to improve the functioning of the sanitation system of the Marseilles conurbation and the quality of its aquatic environments." (Ref. 1)
Partners in this project are the local actor Marseille Provence Metropole,
Presence of GI / NBS research project - mentioned in connection to the project
Yes
Please specify
-Realization of a set of fundamental studies to guarantee the future evolution of the sanitation system (Ref. 1)
Subsidies/investment for GI / NBS in the city - mentioned in connection to the project
Yes
Please specify
MPM (Marseille Provence Métropole) is financing some part of this project (Ref. 2) and "the Water Agency undertakes to finance the operations listed in the Agglomeration Contract" (Ref. 1).
Co-finance for NBS
Yes
Co-financing governance arrangements
Yes
Co-governance arrangement
Other
Please specify other co-financing type
An agglomeration contract with the Rhône, Méditerranée and Corsica Water Agency was signed (Ref. 1).
Was this co-governance arrangement already in place, or was it set up specifically for this NBS?
Set up specifically for this NBS
Financing
Total cost
More than €4,000,000
What is/was the Cost/Budget (EUR) of the NBS or green infrastructure elements?
185,6 millions € for the 5 basins (Ref. 1 and 2)
What are the total amount of expected annual maintenance costs?
Unknown
What is the expected annual maintenance costs of the NBS or GI elements?
Unknown
Please specify cost savings
Unknown
Please specify total cost (EUR)
185,6 millions € for the 5 basins (Ref. 1 and 2)
Source(s) of funding
Public regional budget
Public local authority budget
Corporate investment
Type of fund(s) used
Earmarked public budget
Direct funding (grants, subsidies, or self-financed projects by private entities)
Non-financial contribution
Unknown
Business models
Risk reduction model
Please specify other environmental impact
treatment of bathing water: "the days when the Old Port overflowed with the slightest sustained precipitation or even the bathing water of Marseille beaches with a suspicious color as the smell, on certain days, are over" (Ref. 1).
Which of the involved actors was motivated by this model?
Public actor (e.g. municipality)
Type of innovation
Technological
Process innovation
Infrastructural innovation
Please specify technological innovation
Construction of 5 retention basins to regulate the rain water and to reduce the pollution rate which is "the biggest program on the pluvial in France" (Ref. 1 and 2).
Novelty level of the innovation
The innovation is completely new without connections to previous initiative(s)
Please specify novelty level of the innovation
"Martin Gespereau, General Director of the Rhone-Mediterranean Water Agency Corsica, talks about a historic day with "the biggest program on the pluvial in France. " (Ref. 2)
Replicability/Transferability
Unknown
Please specify Replicability/Transferability
Unknown
Impacts, benefits
Environmental impacts
Water management and blue areas
Improved water quality
Increased protection against flooding
Improved stormwater management
Enhanced protection and restoration of coastal and marine ecosystems
Other
Description of environmental benefits
Water management and blue areas
-Improved water quality: "With a storage capacity of 50,000 M3, this equipment improves the metropolitan area's sanitation system by allowing it to treat wastewater and rainwater, particularly during heavy rain episodes. After 3 years of construction and 50 million euros have been invested by the SUEZ group, the structure will be tested for six months and will come into operation in January 2018" (Ref. 4).
-Increased protection against flooding: "the days when the Old Port overflowed with the slightest sustained precipitation or even the bathing water of Marseille beaches with a suspicious color as the smell, on certain days, are over" (Ref. 1).
-Improved stormwater management: "this gigantic retention basin will make it possible to recover part of the rainwater, during strong stormy episodes" (Ref. 7).
-Enhanced protection and restoration of coastal and marine ecosystems: "Preserving the receiving marine environments and revitalizing them at the outlet of the outfall in the calanque de Cortiou, such are the ambitions of the Aix Marseille Provence metropolis across the Ganay basin. Coupled with SUEZ's dynamic rainwater management solutions, it will prevent the discharge of 1 million m3 of untreated wastewater into the Calanques National Park each year. A reduction of 50% compared to the current situation" (Ref. 4).
Economic impacts
Increase of green jobs (e.g. paid employment positions)
Description of economic benefits
Increase of jobs: For the retention basin located upstream of the Géolide wastewater treatment plant, buried under the Ganay stadium in Marseille completed in 2017, there were "55 people (40 companions + 15 supervisors) on the site for 3 years" and "600 days of work to build the pool" (Ref. 6). This is not a full representation of the work created by the overarching project.
Social and cultural impacts
Health and wellbeing
Gain in activities for recreation and exercise
Description of social and cultural benefits
Health and wellbeing
-Gain in activities for recreation and exercise: "If we do nothing, several beaches will close. Such closures that would be damaging, an ecological and economic failure" (Ref. 1).
Type of reported impacts
Expected impacts
Achieved impacts
Indicators
The project is still ongoing so many indicators are unknown. For the retention basin located upstream of the Géolide wastewater treatment plant, buried under the Ganay stadium in Marseille completed in 2017, the following indicators were identified (Ref. 4):

-m3 capacity
-Diameter
-Depth
-m^2 of diaphragm walls
-Tonnes of poured concrete
-Tonnes of steel used
-Days of work to build the pool
-People on the site for 3 years

Environmental, social and economic impacts
Unknown
Analysis of specific impact categories
Job creation: The NBS created ...
Paid employment positions
Negative impacts: Did the project cause any problems or concerns?
No information was found regarding negative impacts of the project
COVID-19 pandemic
No specific information available as of July 30, 2020. Possibly delays to construction due to stay at home orders active in all of France from March 16, 2020 to May 11, 2020 (https://www.gouvernement.fr/en/coronavirus-covid-19).
Methods of impact monitoring
Process of recording NBS impacts
No evidence in public records
Methods used to evaluate the impacts of NBS
Unknown
Evidence for use of assessment
Presence of an assessment, evaluation and/or monitoring process
Unknown
Presence of indicators used in reporting
No evidence in public records
Presence of monitoring/evaluation reports
No evidence in public records
Availability of a web-based monitoring tool
No evidence in public records
Impact assessment mechanism
Name of any specific impact assessment tools
There is a tool for following the work process of the basins. For instance the "Ganay" basin work progress is available online. (http://www.devisubox.com/dv/dv.php5?pgl=Project/interface&dv_pjv_sPjvName=bassin_retention_ganay)
Link to the output of assessments
http://www.devisubox.com/dv/dv.php5?pgl=Project/interface&dv_pjv_sPjvName=bassi…
Use of GIS in mapping impacts
Yes
Link to GIS monitoring data
http://www.devisubox.com/dv/dv.php5?pgl=Project/interface&dv_pjv_sPjvName=bassi…
Citizen involvement
Citizens involvement in assessment/evaluation
Unknown
Citizens involvement in the analysis of the assessment/evaluation
Unknown
Follow-up to the evaluation / assessment
Unknown
References
Web links relevant to the intervention
Ref. 1
Ref. 2
Ref. 3
Ref. 4
Ref. 5
Ref. 6
Ref. 7
Documents relevant to the intervention
Attachment Size
Agglomeration Contract (Ref. 5) (163.07 KB) 163.07 KB
List of references
1. Métropole Aix Marseille Provence (n.d). "Nous améliorons la qualité des eaux usées". Compétences. (Website not available in 2020).
2. Destimed (2014). "MPM : Un contrat d’agglomération de 185,6 M€ signé pour l’amélioration du système d’assainissement et la qualité du milieu aquatique". Available at: http://destimed.fr/MMP-Un-contrat-d-agglomeration-de (Accessed: July 30, 2020).
3. Métropole Aix Marseille Provence (n.d). "Bassin de rétention de Ganay". (Website not available in 2020).
4. Egis (n.d). "Bassin de rétention d'eaux unitaires Pierre Puget à Marseille". Available at: https://www.egis.fr/action/realisations/bassin-de-retention-deaux-unitaires-pierre-puget-marseille (Accessed: July 30, 2020).
5. Métropole Aix Marseille Provence (2014). "Signature du contrat d’agglomération Améliorer le système d’assainissent et la qualité du milieu aquatique". http://www.eaurmc.fr/fileadmin/espace-presse/documents/DP_Contrat_d_agglo.pdf (Website not available in 2020, see attachment).
6. Suez (2017). "Marseille - Bassin de rétention Ganay : un bassin protecteur du Parc National des Calanques". Tout sur mes services. Available at: https://www.toutsurmesservices.fr/Bassin-Ganay (Accessed: July 30, 2020).
7. Ignasse, Joël (2017). "Avec le bassin Ganay, Marseille va faire face aux orages". Science et avenir. Available at: https://www.sciencesetavenir.fr/nature-environnement/avec-le-bassin-ganay-marseille-va-faire-face-aux-orages_113667 (Accessed: July 30, 2020).
Comments and notes
Additional insights
2017 comment:
Section4/governance/Stakeholders:
Perhaps the EU may not be a direct stakeholders but they influenced this intervention as it is mentioned "to achieve the objectives set by the State and by Europe, MPM (Marseille Provence Metropole) has put in place a program of large-scale work" (Ref. 2).
Pictures of the NBS
/sites/default/files/nbs/images/p1160147copie-b52b0.jpg
Public Images
Marsailles water retention basins
Marsailles water retention basins
https://www.toutsurmesservices.fr/Bassin-Ganay