This chapter underscores the global significance of groundwater as a vital resource for domesticDomestic use, agricultureAgriculture, industryIndustry, and ecosystemsEcosystem. Particularly, the chapter highlights key scientific issues in agricultural hydrogeologyHydrogeology, emphasizing the implications of agricultural irrigation on groundwater resources. Additionally, it discusses the challenges faced in domesticDomestic, industrial, and ecological contexts, including over-extractionExtraction, contamination, and climate-induced changes in water availability. To address these challenges, the chapter proposes strategies for advancing hydrogeologyHydrogeology in the new era, including enhanced research and monitoring, improved data sharing, incorporating citizen scienceScience, enhanced international collaborationCollaboration, planned collaborationCollaboration among academics, industryIndustry, research institutes, and governments, and continued funding and support from governments. By embracing these strategies, the hydrogeological communityCommunity can continue to make significant contributions to the sustainable management and protectionProtection of groundwater resources worldwide.