Tumwater is a city in Thurston County, Washington near where the Deschutes River enters Budd Inlet, the southernmost point of Puget Sound. The population was 12,698 at the 2000 census. Thurston County, which includes the cities of Lacey, Olympia and Tumwater, has a population of 224,100. Tumwater apartments for rent comparison page shows most up to date rent information on Tumwater apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.