Manage water crises and prevent water stress

As a service manager, our priority is to guarantee the continuity of essential services and to organise them to anticipate and manage crises. With the increase in drought episodes due to climate change, our goal is to ensure effective communication of major events, which may affect water and sanitation services, to the relevant decision-makers, so that you always benefit from a reliable and quality service.

To enable you to anticipate periods of scarcity and maintain a constant and reliable supply of water, even in times of drought, we adopt proactive and efficient management of water resources. Thanks to the use of artificial intelligence, we instrument resources (surface water, boreholes, springs, groundwater, etc.) to model their level and behaviour, in order to accurately predict the state of resources in 3 days, 3 weeks, 3 months, 3 years. In an alert situation (drought, low groundwater levels) your users are subject to appropriate preventive and restrictive measures to limit use and maintain groundwater levels, with increased vigilance and consumption restrictions (watering of green spaces only allowed in the evening and at night, for example) until the rain returns, thus ensuring the preservation of your territory's water resources, for sustainable and responsible use. Irrigation must be optimised and strictly regulated in times of water stress to conserve water resources. Consumption limitation may be governed by a system of prefectural decrees in a geographical area (department, municipalities) to guarantee the vigilance of users and preserve the level of the aquifers. Agriculture must adopt sustainable and resilient practices to cope with increasing water stress and preserve water resources.

If a crisis could not be prevented and your territory lacks drinking water due to a deterioration in the quantity and/or quality of available water, we mobilise solutions adapted to your situation. This includes the temporary supply of alternative resources: the deployment of mobile water treatment units, the delivery of water by tankers and the distribution of drinking water to the inhabitants. These measures make it possible to quickly compensate for the drinking water deficit and to meet the urgent needs of the populations affected by the crisis. Our approach aims to ensure the continuity of the supply of drinking water, even in the most critical situations, thus guaranteeing safety and public health.

To protect the health of users, to allow everyone to organise themselves and to avoid tension on drinking water. We are organising communication and consultation with the various water users to share the resource equitably and restore the situation as soon as possible. Clear and transparent communication is essential in crisis management, to inform stakeholders quickly and effectively about the situation and the measures taken to address it. This includes, for example, information on the nature of the crisis, its causes, its impact and the actions taken to ensure the supply of safe drinking water. The objective is to reassure users, prevent stress, encourage cooperation in the implementation of emergency measures (water restrictions) to help manage expectations while waiting for the situation to improve.

Drought exacerbated by climate change is causing water levels to drop, increasing water stress in many countries around the world. In the face of increasing water stress and regular water use limitations, water withdrawals must be strictly regulated to ensure responsible and sustainable management of available water resources.

Storm CIARAN has had a strong impact on water treatment and sanitation infrastructure:

• 1 million homes without electricity
• 370 sites de-energised : 36 drinking water plants shut down, 50 wastewater treatment plants not relieved after 48 hours.
• 2700 simultaneous alarms at the remote control causing its saturation

We have put in place preventive measures upstream to maintain water distribution while mobilising our on-call employees, have organised deliveries of drinking water in high-risk sectors, and have deployed generators to ensure the safety of the facilities, maintain production in degraded mode, and guarantee the quality of the water distributed.

The mobilisation of the teams has made it possible to properly coordinate interventions and material resources, as well as to reorganise processes. Following this storm, we recalled the crisis management procedures, reinforced the material resources and ensured proactive communication with our customers. Our teams are developing new scenarios to improve the continuity of drinking water and wastewater production activities. We will continue to organise training and exercises to anticipate future crises.

The preservation of the resource is a major challenge in the Bordeaux Métropole area. Tap water comes mainly from groundwater. These precious resources provide high-quality water, requiring little treatment to become drinkable. However, these waters, some of which date back thousands of years, are now overexploited. Each year, around 50 million m³ are withdrawn to meet the needs of the region's 800,000 inhabitants. It is now crucial to preserve this precious resource, both in quantity and quality. The pressure on the resource will increase in the years to come with climate change.

The forecasting needs for the territory extend over the period from Spring to Autumn (April – December). The tool is based on forecasting models:

• Conceptual hydrological models: rainfall/FTE/discharge relationship (1, 2 or 3 reservoir models, GR),
• Data-driven machine learning (ML) models (no assumptions about rainfall/runoff relationship), suitable for short-term forecasts (a few days)
• "Hybrid" models (combining the 2 approaches: human + artificial intelligence) adapted to medium-term forecasts (a few months) and adapted to longer-term forecasts (several years) when combined with conceptual models,

These forecasting models make it possible to project medium-term weather scenarios (high/median/low scenario from the previous 20 years) and longer-term weather scenarios (regionalised IPCC scenarios).

With the tool, operators can:

• Refine their forecasting of extraction from fragile resources and assess their production capacity.
• Anticipating maintenance work on additional structures
• Planning water supplies in the context of climate change

This tool allows for reasoned production and is a decision-making aid in the event of a water stress crisis.