The River Wey is the longest tributary of the Thames above London. Other tributaries of the Thames with their courses partially in Surrey include the Mole, the Addlestone branch and Chertsey branch of the River Bourne (which merge shortly before joining the Thames), and the Hogsmill River, which drains Epsom and Ewell.
The riVer wey is the LOngEsT trIbuTarY of thE thaMes aBovE LONDoN OthER TRibUTarIes of the ThaMes wITh THeir cOUrsEs PartIaLly in surrey incLuDE the MolE the aDDLEStOnE braNch and ChERtsey bRAnCH of THe river Bourne (whicH Merge shorTly befORE joIning tHe tHaMes) aNd the Hogsmill riVEr whIch DRAins epSOm And ewell