Physicochemical and botanical limnological characteristics were determined for Boomer Lake, Oklahoma, a recently reexcavated 70 year old urban impoundment. The lake is alkaline (median pH 8.1, range 6.9—8.8) and extremely turbid with suspended clay (median Secchi depths 0.35 m at the shallow upper reach and 0.6 m near the dam, with vertical attenuation coefficients of 1.4—4.7 m−1), although it is slightly clearer than before reexcavation. Boomer Lake is polymictic, with only weak intermittent stratification (median and maximum surface—bottom temperature differentials of 2.0 and 7.6°C at the deepest site) and no evidence of bottom hypoxia. Soluble reactive phosphorus was vertically homogeneous on average, whereas nitrate + nitrite and ammonium tended to be slightly higher at the surface and bottom, respectively. Chlorophyll biomass was very low (~1 mg · m−3), probably because of poor light penetration and possibly low bioavailability of phosphate due to scavenging by suspended clay. Phytoplankton genera (>10 μm) and macrophyte species were documented for the first time in this lake. APotamogeton nodosusgrowth experiment indicated that the fine, anaerobic sediments may slightly depress macrophyte growth rate, and growth was enhanced by sediment ammonium phosphate enrichment. Nevertheless, essentially the entire littoral zone <1 m depth has been colonized by rooted macrophytes, mainlyP. nodosus, Najas guadalupensis, Chara globularisand, more locally,Ludwigia peploides.