Adapting the Paris Metropolitan Area to a Water‑Scarce Future

Annex B. Elaboration of scenarios

Elaboration of the 2050 socio-economic scenario for the region

Trend extrapolation has been used to describe the development of the region through to 2050, if climate change adaptation polices are not strengthened. This approach extrapolates the demographic and sectoral trends observed in recent years to 2050. These extrapolations are then compared with regional and national development and adaptation plans.

• The urban water cycle encompasses all of the processes involved in producing, distributing, using, collecting and treating water in urban areas. Changes in drinking water consumption (and therefore in withdrawals to produce drinking water) are considered to be proportional to population growth in the region, i.e. an increase of 5% by 2050 (INSEE, 2022[1]).

• Agriculture: According to the Chamber of Agriculture, the Institut Paris Région and the Regional and Interdepartmental Directorate of Food, Agriculture and Forestry (DRIAAF in French), the total cultivated area could shrink by 3% by 2050. This trend takes into account the law on net-zero increase in built-up land, which restricts urban development. It therefore reflects only projects that have already been approved in the region. In terms of crops produced, market garden areas could increase eight-fold by 2050 compared with 2020. Extrapolating the rate of increase in irrigated areas between 2010 and 2020 (14%) (DRIAAF, 2022[2]), the study projects a 45% increase in irrigated areas by 2050. This trend is consistent with the Explore 2070 project scenarios (Ministère de l’Écologie, 2012[3]). As a consequence of these various developments, the area devoted to field crops will decrease by 3.5%, with these crops essentially replaced by market garden crops. The scenario keeps the relative proportions of each crop within the major areas (market gardening and field crops) identical to those in 2020 and does not anticipate any change in the type of crops planted in the region.

• Energy production: The region imports around 85% of the energy it consumes, mostly in the form of natural gas, electricity and oil products. Most of the energy produced and consumed by the region is used to generate heat and cooling (86%) and electricity (13%). As the region's hydroelectric productive potential is currently fully exploited (0.4% of the region's energy production), hydroelectric production in the region is not expected to change significantly. On the other hand, the master plan for the Paris cooling network forecasts that the amount of energy delivered by the network is expected to reach 1 000 GWh/year by 2050, i.e. around 2.5 times the quantity/power currently delivered (Ville de Paris, 2019[4]). This trend has been applied to all regional cooling production. Finally, waste-to-energy production is considered stable, given the capacity of existing waste-to-energy plants to cover future incineration needs. In 2021, the quantity of waste incinerated reached 91.6% cent of authorised capacity in the region (ORDIF, 2022[5]); existing facilities therefore have the capacity to absorb the additional waste generated by the population growth in the region (5% by 2050) forecast in our scenario.

• River transport is expected to increase significantly by 2050. Extrapolating the current annual growth rate for river freight (3%) (VNF, 2022[6]) gives a 2.5-fold increase in the current volume of goods transported by river freight by 2050. This trend is in line with the ambition to further develop river transport in the region, as demonstrated by the Seine-Scheldt project, which aims to connect Paris and Le Havre to the major seaports of the North Sea, via the Seine, Oise, Scheldt and Lys rivers. Similarly, river tourism is currently growing by 5% per year (Coopération des agences d’urbanisme de la Vallée de la Seine, 2019[7]), which will result in a 2.7-fold increase in traffic by 2050.

• Manufacturing: The evolution of this sector is more difficult to predict. The trend towards closing industrial sites seen in recent years could be offset by reindustrialisation policies. It has therefore been assumed that there will be a manufacturing industry identical to today's (in composition and value).

• Built environment: Assuming that the Elan Act governing new construction eliminates the risk of clay shrinkage and swelling, the number of homes exposed to this risk in 2050 will not change compared with the current number.

• Ecosystems: The scenario assumes that the extent of natural areas where there is little or no human activity will remain the same as today. The regional biodiversity strategy for the region in 2020-30 (Conseil Régional d'Ile de France, 2019[8]) commits to safeguarding existing ecosystems but does not include any plans to develop them further in the region.

Table A B.1. Socio-economic development trends in the region through to 2050

Extrapolation of past socio-economic development trends in the region to 2050

System	Subsystem	Change in 2050 (2020 baseline)
Agriculture	Market gardening (area)	8-fold increase
	Livestock farming	40% reduction
	Total useful agricultural area	3% reduction
	Arable crops (area)	3.5% reduction
	Irrigated area	45% increase
Demographics	Paris metropolitan area’s population	5% increase
Urban water cycle	Demand for drinking water	5% increase
	Sanitation	5% increase
Energy	Electricity generation (recovery of household waste)	No change
	Cooling	2.5-fold increase
	Electricity generation (hydroelectric)	No change
Industry	Industrial activity	No change
Water transport	Water freight	2.4-fold increase
	Pleasure boats	No change
	River tourism	3.2-fold increase
Ecosystems	Natural (non-urban) ecosystems	No change

Source: Authors, using the following data and documents. Agriculture: (Conseil Régional d’Ile de France, 2021[9]), (DRIAAF Ile de France, 2021[10]), (DRIAAF, 2022[2]), (Ministère de l’Écologie, 2012[3]). Demographics: INSEE data: https://www.insee.fr/fr/statistiques/6666275; Urban water cycle: ; Energy: expert testimony, Regional Waste Observatory (ORDIF in French), 2022_[5]; Urban spaces River transport: (VNF, 2022[6]), (Coopération des agences d’urbanisme de la Vallée de la Seine, 2019[7]); Ecosystems: (Conseil Régional d'Ile de France, 2019[8]).

Construction of drought scenarios

Methodology

Three drought scenarios have been constructed to assess the potential economic impact of such a phenomenon in 2050 and 2100. These scenarios reflect the most severe events simulated by climate and hydrological projections. Each scenario describes changes in the status of the various resources (soil moisture, groundwater and rivers) over one year, taking into account the impact of climate change on water resources, as well as the influence of existing uses and infrastructure (creation of reaches, reservoirs, etc. on the Seine). Scenario 1 describes a severe drought, combining a historical low-water scenario (1921) and a historical soil dryness scenario (1976), both considered to be likely events by 2050. Groundwater levels have been modelled for 2050 by extrapolating the trends observed between 2020 and 2022, i.e. a 6% reduction in aquifer height compared with 2020. Surface water temperature is defined as the median temperature profile derived from a multi-year modelling of Seine water temperature in an RCP8.5 scenario by 2050. Scenario 2 describes the simultaneous occurrence of a drought identical to the one in scenario 1 and a very hot year, where the temperature profile matches the 90th percentile of daily temperature curves simulated for an RCP 8.5 scenario between 2040 and 2070. In view of the worsening climate trends between now and 2100, scenario 3 has been designed as a worse version of the second drought scenario. This adverse scenario reflects projected reductions in average flow rates (-20%) and increases in average surface temperatures (+2°C) between 2050 and 2100. Groundwater levels have been modelled assuming a downward trend in groundwater levels between 2050 and 2100. In the absence of available simulations, soil dryness in scenario 3 is identical to that in scenario 2. These three scenarios are based on a combination of climate projections, surface and groundwater hydrology projections, and historical data.

Table A B.2. Characteristics of water scarcity scenarios

Scarcity factor	Water source	Scenario 1	Scenario 2	Scenario 3
River flow rate	Surface water (rivers)	1921 drought	1921 drought	1921 drought minus 20%
Agricultural drought	Soil moisture	1976 drought	1976 drought	1976 drought
Water temperature	Surface water (rivers)	Median temperatures 2050	Over 25°C for 2 months	Over 25°C for 3 months
Aquifers	Groundwater	6% reduction in aquifer height	6% reduction in aquifer height	12% reduction in aquifer height
Low-water support	EPTB reservoirs	1921 drought	1921 drought	1921 drought minus 20%

Source: Authors.

Selection of aquifers and rivers to be studied

Although all water resources are exploited in the region, some are used more heavily than others. As detailed in Table A B.3, the Seine and Marne rivers account for 99% of surface water abstraction. So, for the sake of simplicity and due to a lack of data, the study only models low water levels for these two rivers. Activities that abstract water from other minor watercourses (tributaries of the Marne or Seine) are considered as abstracting water from one of these two main rivers. From the two major rivers, the confluence closest to the river from which the water is abstracted is chosen.

Table A B.3. Water abstraction by source in the Paris metropolitan area (2018)

Type	Source	Volume (m3)	Percentage of total water withdrawals (%)
River	All rivers	2.49E+10	98.6%
	Seine	2.45E+10	97.2%
	Marne	2.58E+08	1.0%
	Oise	68 760 671	0.3%
Aquifers	All aquifers	3.51E+08	1.4%

Source: National Abstraction Database (2018).

To identify the most significant sources of groundwater for abstraction, the data in the national database of quantitative water abstractions are disaggregated by department. The departments of Seine-et-Marne (77), Yvelines (78) and Essonne (91) account for almost 90% of groundwater abstraction in the region. These departments are fed by the Champigny aquifer and the Ypresian/Lutetian, Craie and tertiary formation aquifers. Due to a lack of data on other aquifers, and because it is used as a reference for drought orders in six of the region's eight departments (Table A B.4), only the state of the Champigny aquifer is considered in this study, along with the restrictions applied to all groundwater abstraction in the region as a result of its water level.

Table A B.4. Groundwater abstraction by department (2018)

Source	Department	Volume abstracted (millions of m3)	Share of regional groundwater abstraction
Groundwater	77	161	45.8%
	78	120	34.2%
	91	29	8.4%
	95	23	6.5%
	94	6.9	2.0%
	92	6.1	1.7%
	93	5.0	1.4%
	75	0.4	0.1%
	Total	351	100.0%

Source: National Abstraction Database (2018).

Selection of baseline stations

As most of the impacts of droughts are due to the application of drought orders, the flow of each of these three rivers and the level of the Champigny aquifer are modelled at the baseline stations mentioned in the departmental drought orders. The baseline station for the Seine is Alfortville, while Gournay-sur-Marne is used for the Marne. Groundwater levels have been modelled for the Champigny Ouest aquifer at Montereau-sur-le-Jard.

River flow rate

The flow rate in the Marne and Seine rivers is equal to the natural flow of the river plus support from the EPTB reservoirs, minus water consumed for various uses.

Simulations from climate and hydrological models are used to determine the impact of climate change on natural river flow rates. Figure A B.1 shows simulations of natural river flow rates from (Boé et al., 2018[11]). The region could experience more extreme droughts, far more severe than those experienced over the last 20 years. More precisely, a drought similar to the one in 1921 would become a probable (albeit extreme) event by 2050. This 1921 drought is therefore used to model river flow rates in scenarios 1 and 2. The Seine–Normandy River Basin Committee estimates that by 2100, river flow rates could decline by 10-30% by 2070-2100, compared with 1970-2005 (Comité de Bassin Seine Normandie, 2016[12]). A 20% decline in flow rates compared with the 1921 drought has therefore been used in scenario 3.

Figure A B.1. Severity and duration of agricultural and hydrological droughts in the Seine–Normandy river basin (1961-90 and 2031-60)

Note: The figure on the left shows the distribution of mean annual flow rates in a late-20th century climate context, while the figure on the right shows the likely distribution in the mid-21st century. Each point represents a simulation year, and each colour represents a specific (hydrological) climate model.

Source: (Boé et al., 2018[11])

In its study on low-water support, EPTB reconstructed the natural flow of the Seine at Alfortville and the Marne at Gournay-sur-Marne for the 1921 drought. EPTB also estimated monthly water consumption by use for each river. These consumption figures have been corrected in proportion to changes in the various uses emanating from the 2050 socio-economic scenario.

Finally, the natural flow minus consumption is supplemented by a constant flow from the reservoirs from 1 June to 30 November.

Figure A B.2 shows changes in the "actual" flow rate1 of the Seine at Alfortville, as well as flow rates for the different levels of drought orders.

Figure A B.2. Flow rate of the Seine at Alfortville (Scenarios 1, 2 and 3)

Source: Authors, based on flow rate and consumption data from EPTB Seine Grand Lacs.

Groundwater levels

As aquifers are reserves of water (not flows like rivers), groundwater levels change gradually, and not on an annual basis like rivers. Groundwater levels for 2050 and 2100 have therefore been estimated by extrapolating current trends, corrected for changes in usage and increases in average rainfall. The intention behind this approach is to analyse what would happen if the current dynamics of groundwater recharge and depletion were to carry on to 2050. Data from ADES, the French national groundwater data access portal, can be used to analyse historical groundwater levels. Figure A B.3 shows changes in the piezometry of the Champigny Ouest aquifer, illustrating a gradual decrease in the aquifer's piezometric level between 2020 and 2022. Without taking into account the lack of recharge following the 2022 drought, the maximum groundwater level has declined by an average of 0.4% per year. This trend has been corrected to account for changes in consumption and the impact of climate change on groundwater recharge. In our scenario, demand for water to be used for drinking water and irrigation (which account for 93% of the region's groundwater use) increases by 8% by 2050. Furthermore, AQUI'Brie estimates that climate change will lead to an average increase in precipitation. This will increase groundwater recharge by 10% by 2060 compared with 2020, and by 12% by 2100. By combining these three effects (long-term decline in groundwater level, increase in average recharge and increase in demand for water), an average rate of change in groundwater levels can be calculated and then projected to 2050. For the projection to 2100, needs and uses are unchanged from those of 2050 in our socio-economic scenario. The only thing that remains is the continuing decline in groundwater levels, partly offset by the increase in average rainfall, and therefore in groundwater recharge.

Figure A B.3. Changes in the level of the Champigny aquifer at Montereau-sur-le-Jard (2010-23)

Source: Authors, based on ADES data.

To study the impact of groundwater scarcity, the annual dynamics of groundwater recharge and depletion must also be modelled. Figure A B.3 shows that groundwater recharge and depletion periods are seasonal and remain broadly unchanged from year to year: the aquifer fills up in winter and early spring, and empties in summer and autumn.

The annual change in groundwater levels in each scenario is the result of linear extrapolation of recharge and depletion trends. These make it possible to define the maximum (on 1 April) and minimum (on 1 December) levels for each scenario. The scenarios use a schematic version of seasonal changes in groundwater levels (see Figure A B.3). The aquifer empties linearly from 1 April to 1 December and fills up from 1 December to 1 April. The annual profile is obtained by linearly linking the maximum and minimum levels. Figure A B.4 illustrates the modelling of the Champigny Ouest aquifer height for scenarios 1 and 2.

Figure A B.4. Annual changes in the level of the Champigny aquifer (Montereau-sur-le-Jard, Scenarios 1 and 2)

Source: Authors.

River temperature

Excessive water temperature leads to scarcity, as it can limit certain uses such as power generation or industrial cooling. EPTB has modelled the water temperature in the Seine at the Suresnes Lock through to 2050. The data supplied by EPTB show a simulated daily temperature for each year between 2010 and 2070 for the RCP8.5 scenario. As shown in Figure 5.5, scenario 1 describes the plausible median temperature through to 2050 and uses the median temperature profile (0.5 percentile). Scenario 2 has been designed to study the simultaneous occurrence of a historic 1921 drought and a warm year, and therefore uses the 90th percentile of this distribution. Finally, the temperature in scenario 3 has been modelled as that of scenario 2 plus 2°C, i.e. the average temperature increase anticipated by the RCP8.5 scenario between 2050 and 2100 (Ministère de la Transition Écologique, 2023[13]). As the Seine holds most of the water used for energy production, the Seine temperature modelled at Suresnes has been applied to all water-dependent uses in the region.

Figure A B.5. Changes in the temperature of the Seine at Suresnes (Scenarios 1, 2 and 3)

Source: Authors, based on EPTB temperature data.

EPTB lake filling and management

The organisation that manages the reservoirs has estimated the fill level of each reservoir in the event of the 1921-style low-water levels considered in scenarios 1 and 2 of the study. These fill rates range from 24% for Lake Seine to 36% for Lake Aube and are used in scenarios 1 and 2. For scenario 3, in which the river flow rates feeding the lakes have been estimated to be 20% lower than in scenarios 1 and 2, the fill rates of each lake are 20% lower than in scenarios 1 and 2.

To also take into account the influence on lake replenishment of evaporation caused by rising temperatures in the region, the study draws on forecasts by Météo France (Météo France, 2019[14]). The evaporation loss that has been used in the study is 700 mm per year (identical in all three scarcity scenarios). This loss has been multiplied by the surface area of the lakes to estimate the quantity of water lost over the course of a year.

The volume of water available to support low water levels in summer (up to and including 31 October) in each scenario corresponds to the volume of the operating storage of each lake, multiplied by the lake fill rate for each scenario (Table A B.5), minus evaporation. If required, the reserve storage can also be used to maintain low-water support after October. Low-water support flow for the lakes is assumed to be constant from June to October and has therefore been calculated as the available volume (operating storage) in each lake divided by the emptying time (five months). Given the natural flow profiles, prolonged low-water support is required through November and December and corresponds to the volume of the reserve storage in each lake divided by the emptying time (two months). The Marne is supported solely by the Marne Lake, and the Seine by the sum of the flows from the four reservoirs.

Table A B.5. Calculation of low-water support flow from EPTB Seine Grands Lacs reservoirs

Low-water support flow from lakes in scenarios 1 and 2

Low-water support from EPTB reservoirs (scenarios 1 and 2)
Lake	Fill rate	Dead storage (million m3)	Reserve storage (million m3)	Operating storage (million m3)	Lake surface area (km2)	Evaporation loss (mm)	Low-water support flow SUMMER (1 June to 31 October) (m3/s)	Low-water support flow WINTER (1 November to 31 December) (m3/s)
Marne	26%	10	15	325	48	700	2.5	2.8
Aube	36%	3	21	150.5	23.2	700	1.7	3.9
Seine	24%	8	12	185	23.2	700	1.0	2.3
Pannecière	34%	6	6	68	5.2	700	0.9	1.1

Source: Authors, based on fill rates from EPTB simulations and Météo France evaporation data.

Soil dryness

A model of the impact of drought on agricultural yields developed by the CCR has been used to estimate the impact of soil dryness on agriculture. This model uses a unique dryness indicator to calculate the impact of given weather conditions on wheat, barley and grass yields. Using simulations from climate models that stretch through to 2050, the model is able to establish a distribution of potential future yield losses. Drawing on the highest deciles of simulated yield losses, it is possible to identify wheat and barley yield losses resulting from an extreme drought event by 2050 (Table A B.6). To estimate the impact of such an event on other crops such as rapeseed, potatoes, etc. (not included in the model), the wheat yield losses estimated by the model are compared with historical wheat losses in the region. The losses of 22% and 24% estimated by the model for wheat and barley respectively (Table A B.6) are similar to historical yield losses resulting from the 1976 drought. Thus, by calculating the yield losses caused by this 1976 drought for other crop types, it is possible to estimate the overall impact of an extreme drought by 2050.

Table A B.6. Modelling the impact of drought on wheat and barley yields

	Common wheat		Barley
	Current climate	2050 (RCP 8.5)	Current climate	2050 (RCP 8.5)
Probability of drought event occurring (Loss rate > 0%)	35%	44%	35%	44%
Average crop losses for the region	4%	5%	4%	6%
90% quantile drought events	5%	12%	10%	18%

Source: Authors, based on data provided by the CCR.

Threat to river transport posed by droughts

Minimum navigation flow on the Seine

The Seine accounts for the bulk of freight and tourist river traffic in the region (VNF, 2019[15]). To enable navigation on the river, numerous locks have been built, making the Seine a river laid out in "reaches" (stretches of water between two locks). The river is also supported by reservoirs. This infrastructure allows the depths required for navigation to be maintained even with relatively low natural flow rates. This section aims to calculate the minimum flow rate of the Seine below which navigation is threatened, in order to assess the resilience of river transport on the Seine to the drought events considered in this study.

Threats to river navigation emerge during low-water periods when the river's flow rate is no longer able to guarantee the depth required for navigation and/or when river traffic can no longer be absorbed, particularly at critical points such as locks. The creation of reaches on the Seine ensures that the required depth is maintained if the flow rate allows the reach to be filled between two passages of the lock. The minimum flow rate required for "normal" navigation on the Seine is therefore equal to the quantity of water lost when a vessel passes through a lock divided by the time available for filling between passages. To establish the critical flow rate for all navigation on the Seine, the calculations are carried out for the Suresnes Lock, a critical lock because it has the highest lock volumes, and therefore "consumes" the most water.

The quantity of water consumed per lock is equal to the lock volume. The Suresnes Lock is made up of three locks of different sizes, which operate alternately. The average volume per lock is therefore equal to the average volume of these three locks, i.e. approximately 9 300 m³. The time available for filling the lock depends on the number of passages through the lock that can be completed in a given time. According to VNF, a maximum of nine passages through the lock can be completed every hour. Since a passage through the lock is completed during the filling or emptying phase, this means it can be emptied a maximum of six times per hour. The minimum flow required for the lock to operate correctly, and thus for navigation to be possible on the Seine, is therefore equal to (9 300*6)/(3 600)=15.5 m³/s. This minimum flow rate is not breached in scenarios 1 and 2 (minimum 22 m3/s), and is breached for only four days in early December in scenario 3, when the lakes stop supporting low water levels. Analysis of the available data therefore means that any impact on freight and tourist traffic on the Seine as a result of water scarcity can be ruled out.

Resilience study for the Seine-Nord Europe Canal

The opening of the future Seine-Nord Europe Canal, which will link Compiègne (60) to Aubencheul-au-Bac (59) in 2030, will be a key factor driving an increase in river traffic in the Paris metropolitan area. Studying the resilience of this canal to severe low-water episodes is therefore vital when assessing the impact of drought on river transport in the region.

Water for the canal is drawn from the Oise, with support from the Louette reservoir. According to data available on the Seine-Nord Europe Canal website (Société du Canal Seine-Nord Europe, 2022[16]), this 14 million m³ reservoir can supply the canal for four months. Thus, the flow rate required for the canal to function properly is 1.3 m³/s. The absence of data or simulations on the flow rates of the Oise at Compiègne (where the Oise joins the canal) during an event similar to that in 1921 means that this critical flow rate cannot be compared with the potential flow rates during extreme drought events. On the other hand, the calculated critical flow rate is less than half the minimum daily flow rate observed at Sempigny upstream of Compiègne (3 m³/s in August 1976) over the 1955-2023 period. In the case of the Seine at Alfortville, flow rates equivalent to the simulated minimum flow rate in 1921 have been observed historically. It therefore seems reasonable to believe that the canal will not be adversely affected by drought events similar to those considered in this analysis.

References

[11] Boé, J. et al. (2018), Scénarios sécheresse sur le bassin Seine-Normandie.

[12] Comité de Bassin Seine Normandie (2016), Stratégie d’adaptation au changement climatique du Bassin Seine-Normandie, Comité de Bassin Seine-Normandie.

[9] Conseil Régional d’Ile de France (2021), PLAN RÉGIONAL POUR UNE ALIMENTATION LOCALE, DURABLE ET SOLIDAIRE L’ALIMENTATION DES FRANCILIENS : UN ENJEU DE SOUVERAINETÉ, DE SANTÉ ET DE RELANCE, Région Ilede France.

[8] Conseil Régional d’Ile de France (2019), Stratégie régionale pour la biodiversité 2020-2030, https://www.iledefrance.fr/espace-media/applis_js/rapports_cp-cr/2019-09-19/CR-2019-060.pdf.

[7] Coopération des agences d’urbanisme de la Vallée de la Seine (2019), Le Tourisme Fluvial et Maritime dans la Vallée de la Seine, https://www.vdseine.fr/fileadmin/Site_Vallee_de_la_Seine/Rencontres2019/4juillet2019/des_escales_aux_territoires.pdf.

[2] DRIAAF (2022), Agreste Île-de-France - Mémento 2022.

[10] DRIAAF Ile de France (2021), Recensement agricole 2020 - 1ers résultats.

[1] INSEE (2022), Projections démographiques en Île-de-France à horizon 2070 : vieillissante, la région resterait la plus jeune de France métropolitaine, https://www.insee.fr/fr/statistiques/6666275.

[14] Météo France (2019), Evaporation sur des Lacs Reservoirs, https://services.meteofrance.com/changement-climatique/evaporation-sur-des-lacs-reservoirs.

[13] Ministère de la Transition Écologique (2023), DRIAS - Les futurs du climat, http://www.drias-climat.fr/decouverte/cartezoom/experience/EUROCORDEX2020_DISTRIBUTION_ELAB/Q05/RCP4.5/RCP4.5/H2/APAV/APAV/A1 (accessed on 27 March 2023).

[3] Ministère de l’Écologie, D. (2012), Explore 2070: Synthèse du projet Explore 2070: Prospective socio-économique et démographique.

[5] ORDIF (2022), L’incinération des déchets non dangereux en Ile de France, https://www.ordif.fr/fileadmin/DataStorage/user_upload/ORDIF_Notice_UIDND_2020-2021_v6_schema_HD.pdf (accessed on  January 2023).

[16] Société du Canal Seine-Nord Europe (2022), Chiffres Clés.

[4] Ville de Paris (2019), Schéma directeur du réseau de froid parisien, https://www.api-site.paris.fr/paris/public/2019%2F6%2FSch%C3%A9ma%20Directeur.pdf.

[6] VNF (2022), Bilan 2021 du fret fluvial : des trafics en hausse sur le bassin de la Seine, https://www.vnf.fr/vnf/presses/bilan-2021-du-fret-fluvial-des-trafics-en-hausse-sur-le-bassin-de-la-seine/.

[15] VNF (2019), Rapport d’activité 2019, https://www.vdseine.fr/fileadmin/Site_Vallee_de_la_Seine/Ressources/logistique_et_transport_de_marchandise/Rapport_d_activite_2019_de_VNF_Bassin_de_la_Seine.pdf.

Note

← 1.  Actual flow rate is the flow rate that can be observed and measured in the river. It therefore corresponds to the natural flow rate, plus lake support and minus consumption.