A pilot study was undertaken to assess the potential fertility of lentic waters and to ellucidate the ecology of aquatic flora. In addition, studies were performed at microcosmal level and the results, so obtained, were applied at field level, to forsee the impact of nutrients on natural waters. Three major water resources of Bhopal, Upper lake (UL), Lower lake (LL) and Mansarovar reservoir (MR), have been selected for present investigation.