The purpose of this study is to utilize the feasibility of lightweight aggregate (LWA) produced from waste and its application in lightweight concrete (LWC). LWA was produced from wet sewage sludge as a principal material and reservoir sediment as an additive material using sintering temperatures of 1,050?1,250°C in order to improve their physical properties. The selected LWA was used as coarse aggregate in the manufacturing of high-flowing LWC. Results showed that a proper amount of reservoir sediment addition improved the aggregate size expansion, decreased bulk density, and also increased strength of aggregate. As a general overview, all aggregates produced in this study had a bulk density less than 2.0 g=cm3. In addition, under proper sintering temperatures the water absorption of aggregate having reservoir sediment addition could be significantly reduced as low as 1.9%. A very good workable LWC was obtained with 28-day age compressive strength of 31.25 MPa. The surface resistivity and ultrasonic pulse velocity results proved that the LWC can be considered as a good-quality concrete.