Besides stormwater effects on existing habitats, a related issue of interest deals with the creation of aquatic habitat in stormwater management facilities. Urban stormwater Best Management Practices (BMPs) were originally developed for mitigating the impacts of urbanization on the hydrological cycle and water quality, but such objectives were later expanded to include environmental amenities, such as the protection or creation of aquatic habitats (Jones et al., 1997). The issue of habitat creation is not without some controversy, because these new demands on BMPs may be in conflict with the fact that BMPs are primarily passive treatment facilities designed to retain sediment and pollutants. The issues of habitat conditions in stormwater facilities were addressed by Bishop et al. (2000a, 2000b) who focused on water quality and toxicity issues at fifteen stormwater management facilities, including eleven stormwater ponds and four constructed wetlands. The study found that wildlife used all of the fifteen stormwater facilities, with species richness classified as low to moderate; all stormwater facilities contained contaminants, generally at low levels, except for some persistent contaminants in sediment and water exceeding the Canadian guidelines for water and sediment quality in the freshwater environment; bioaccumulation of some persistent contaminants (e.g., PCBs) in red-winged blackbird eggs was found at two sites; and toxicity findings – sediment from one site in a commercial/light industrial area was toxic to invertebrates in a short-term bioassay, and conditions were toxic to frog development at one of four residential sites studied, and no site contained sediments toxic to fish in short term bioassays. Consequently, the authors concluded that the stormwater facilities studied (built in the mid-1980s) did not provide good habitats for fish and wildlife, because of their potential for contamination.