This　work　aimed　to　reflect　the　advancements　in　water-related　science,　technology,　and　policy　and　shed　light　on　future　research　opportunities　related　to　water　through　a　systematic　overview　of　Water　Research　articles　published　in　the　first　21.5　years　of　the　21st　century.　Specific　bibliometric　analyses　were　performed　to　i)　reveal　the　temporal　and　spatial　trends　of　water-related　research　themes　and　ii)　identify　the　underlying　connections　between　research　topics.　The　results　showed　that　while　top　topics　including　wastewater　(treatment),　drinking　water,　adsorption,　model,　biofilm,　and　bioremediation　remained　constantly　researched,　there　were　clear　shifts　in　topics　over　the　years,　leading　to　the　identification　of　trending-up　and　emerging　research　topics.　Compared　to　the　first　decade　of　the　21st　century,　the　second　decade　not　only　experienced　significant　uptrends　of　disinfection　by-products,　anaerobic　digestion,　membrane　bioreactor,　advanced　oxidation　processes,　and　pharmaceuticals　but　also　witnessed　the　emerging　popularity　of　PFAS,　anammox,　micropollutants,　emerging　contaminants,　desalination,　waste　activated　sludge,　microbial　community,　forward　osmosis,　antibiotic　resistance　genes,　resource　recovery,　and　transformation　products.　On　top　of　the　temporal　evolution,　distinct　spatial　evolution　existed　in　water-related　research　topics.　Microplastics　and　Covid-19　causing　global　concerns　were　hot　topics　detected,　while　metagenomics　and　machine　learning　were　two　technical　approaches　emerging　in　recent　years.　These　consistently　popular,　trending-up　and　emerging　research　topics　would　most　likely　attract　continuous/increasing　research　input　and　therefore　constitute　a　major　part　of　the　prospective　water-related　research　publications.