This paper reports a study on distribution characteristics of phosphorus and its species in 20 sediments samples from Lakes Baihua and Aha, based on the technique of sequential extraction. Baihua and Aha, two man-made reservoirs, are key drinking-water sources. The results, compatible with local geophysical characteristics, indicate that in sediments from both lakes, the concentrations of inorganic phosphorus (IP) were higher than those of organic phosphorus (OP), and the IP consisted mainly of calcium-bound phosphorus (Ca-P), which may temporarily control phosphorus release. Moreover, the concentrations of total phosphorus (TP) in both lakes sediments were high, thus phosphorus release potential and bioavailability were highly significant. Further statistical analyses revealed significant correlations with two extractable principal components allowing interpretation of possible origins of phosphorus loadings. Furthermore, available remediation measures were briefly evaluated for both lakes in consideration of their distinctive environmental features.