Yunnan Water Investment Co., Limited, an investment holding company, designs, develops, constructs, operates, and maintains municipal water supply, and wastewater and solid waste treatment facilities in the People's Republic of China and internationally. It operates through five segments: Wastewater Treatment, Water Supply, Solid Waste Treatment, Construction and Sales of Equipment, and Others. It constructs and operates wastewater treatment projects, water supply projects, and solid waste treatment projects; undertakes build and transfer (BT) projects, and engineering-procurement-construction (EPC) projects; and produces, sells, and installs equipment for wastewater treatment, water supply, solid waste treatment, and other infrastructure facilities. It undertakes operation and maintenance (O&M) projects for wastewater treatment and water supply facilities owned by third parties; and offers technical and consultancy services. As at 31 December 2021, it had 134 concession wastewater treatment projects, including 7 build-own-operate (BOO), 69 build-operate-transfer (BOT), 2 transfer-own-operate (TOO), 27 transfer-operate-transfer (TOT) projects, 1 rehabilitate-operate-transfer (ROT), and 28 municipal environment comprehensive treatment projects, with total daily treatment capacity of approximately 3,553,400 tonnes; 67 concession water supply projects comprising, 15 BOO projects, 35 BOT projects, 11 TOT projects, and 6 municipal environment comprehensive treatment projects with total daily capacity of approximately 2,449,100 tonnes; 24 solid waste treatment projects with annual treatment capacity of approximately 4,081,900 tonnes; 10 BT projects and 13 EPC projects; and 26 O&M projects. The company was formerly known as Yunnan Water Industry Investment and Development Co., Ltd. and changed its name to Yunnan Water Investment Company Limited in July 2014. The company was founded in 2009 and is based in Kunming, the People's Republic of China.