According to the IPCC reports, the effects of climate change are well present from several decades ago, and it is expected to become even more pronounced during the remainder of the twenty-first century. The river basin system is defined as a complex of interaction between aquatic and terrestrial ecosystems. The interface between these ecosystems results in different responses of the river regime ranging from floods to low flow. The instability of alluvial valley due to geomorphological and fluvial dynamics, represents an additional challenge for the riparian societies face to climate changes. The Garonne River, the third largest French Atlantic River in terms of discharge, flows down in the Garonne Valley, the largest occupied and cultivated alluvial plain in France. This area is influenced by a wide range of Oceanic, Mediterranean, and mountainous climates. Hence, the complex Garonne River regime is influenced by the precipitation generated over the Massif Central and the French and Spanish Pyrenees Mountains. The surrounding alluvial aquifer, which forms an important part of this system, maintains a strong hydraulic connection with the river and sustains its low flow. Consequently, this aquifer is extremely sensitive to meteorological changes and hence to recharge system variation. The inhabitants in this area are strongly depending to the river and its alluvial aquifer. However, the impact of climate changes on socio-economic activities could be significant in this area. The adaptation to these changes creates additional challenges for decision-makers and becomes a major objective of the watershed policy. The trends assessment of the Garonne River's discharge over the last fifty years has shown a decrease in average annual discharges and substantial decrease in low flows. The dry periods are starting earlier and becoming more severe and longer. Upstream, the snow cover shows a decrease in thickness and duration, which has a negative impact on the river’s discharge and consequently on the groundwater recharge ratio. Groundwater measurements show a general decrease in water level. The observations show that most of the wells located close to the river have dried up during the dry periods since the alluvial aquifer drains into the river during these periods. The groundwater level reduction could have a negative impact on agriculture, wetlands, and river ecosystems. Thus, the implementation of adaptation measures has been initiated. The artificial recharge of the alluvial aquifer is considered as an adaptation strategy to address the effect of climate change and sustains the low flow of the river. In addition, this strategy will help to buffer the river temperature during the low flow periods. Several pilot sites in the Garonne Valley are under investigation for testing the artificial recharges. The first site, where artificial recharge has been tested since 2019, is located near the city of Agen, where the runoff is collected in a retention basin and is used to recharge the alluvial aquifer. Groundwater level in the wells near the retention basin have increased by about 1 m following rainfall events. The results of the groundwater modeling show (1) a similar magnitude aquifer response to the induced infiltration and (2) that the infiltrated water would take about 4 months to reach the Garonne River, which is an appropriate time to maintain the river's low flow, since recharge takes place in spring. Another site that has been tested is located near the city of Marmande, where the surface water from the Lateral Canal of the Garonne River has been used as a source to recharge the alluvial aquifer in May 2023. The infiltrated water has created a piezometric dome and the groundwater level has increased by 15 and 33 cm into two boreholes located about 40 m upstream and downstream of the infiltration site respectively. This experiment will be carried out on a larger scale, and further groundwater measurements and modeling will be carried out for this and other selected sites in the near future.