 In past years, Rainbow Lake has also had a significant problem with invasive aquatic weeds, particularly the Eurasian watermilfoil, "Myriophyllum spicatum".Efforts by the local volunteer group Show Low Creek Watershed Enhancement Partnership (SLCWEP), in conjunction with the Little Colorado River Plateau Resource Conservation and Development Area, Inc., resulted in a systemic herbicide treatment of the lake in the summer and fall of 2011.The results were not as good as hoped, with the equally problematic coontail weed rapidly replacing the watermilfoil in the lake.