Tianjin,　a　coastal　metropolis　in　north　China,　has　grappled　with　land　subsidence　for　nearly　a　century.　Yet,　emerging　evidence　suggests　a　notable　decrease　in　subsidence　rates　across　Tianjin　since　2019.　This　trend　is　primarily　attributed　to　the　importation　of　surface　water　from　the　Yangtze　River　system　via　the　South-to-North　Water　Diversion　Project,　initiated　in　December　2014.　Utilizing　Sentinel-1A　Interferometric　Synthetic　Aperture　Radar　(InSAR)　data　(2014-2023),　this　study　reveals　that　one-third　of　the　Tianjin　plain　has　either　halted　subsidence　or　experienced　land　rebound.　As　a　result,　the　deep　aquifer　system　(similar　to-200　to　-450　m)　beneath　one　third　of　the　Tianjin　plain　has　completed　a　consolidation　cycle,　leading　to　the　establishment　of　new,　locally　specific　preconsolidation　heads.　The　identification　of　the　newly　established　preconsolidation　head　seeks　to　answer　a　crucial　question:　How　can　we　prevent　the　reoccurrence　of　subsidence　in　areas　where　it　has　already　ceased?　In　essence,　subsidence　will　stop　when　the　local　hydraulic　head　elevates　to　the　new　preconsolidation　head　(NPCH),　and　permanent　subsidence　will　not　be　reinitiated　as　long　as　hydraulic　head　remains　above　the　NPCH.　The　difference　of　the　depth　between　current　hydraulic　head　and　the　NPCH　defines　the　safe　pumping　buffer　(SPB).　This　study　outlines　detailed　methods　for　identifying　the　NPCHs　in　the　deep　aquifer　system　from　long-term　InSAR　and　groundwater-level　datasets.　Determining　NPCHs　and　ascertaining　SPBs　are　crucial　for　estimating　how　much　groundwater　can　be　safely　extracted　without　inducing　permanent　subsidence,　and　for　developing　sustainable　strategies　for　long-term　groundwater　management　and　conservation.