Fresh Water ProblemsGroundwater Function in Water Supply of Population, Industry, and AgricultureMain NotionsModern State and Main Principles of Rational Groundwater UseGroundwater OverexploitationGroundwater Resources and Their Uses in RussiaPrinciples of Regional Assessment and Mapping Natural Groundwater ResourcesGroundwater Contribution to Water and Salt Balance of Rivers, Lakes, and SeasEnvironment and Groundwater PollutionInterconnection Between Groundwater Pollution and EnvironmentHuman Impact on the GroundwaterGroundwater Pollution in RussiaGroundwater VulnerabilityPrinciples of Assessing and Mapping Groundwater VulnerabilitySome Regional InvestigationsEcological Consequences of Groundwater Pumping OutInfluence of Groundwater Withdrawal on River RunoffInfluence of Groundwater Withdrawal on Vegetation and AgricultureInfluence of Groundwater Withdrawal on Land Surface SubsidenceInfluence on Groundwater Withdrawal on Sea Water Intrusion to the Coastal ZoneGroundwater Use in Public HealthConclusionReferences.