Aquatic plants and weeds have existed in the delta for over a century. While they're not new to Discovery Bay, they have become a much larger problem in recent years.

RD 800 is aggressive in our efforts to rid Willow Lake of these aquatic pests. The most common weeds you'll see in the lake are Water Hyacinth and Egeria Densa. 

Water Hyacinth

Water Hyacinth is an invasive species of aquatic plant that has existed in the US for over 100 years. They are characterized by aa cluster of round leaves and bloom purple flowers in the summer. While they are beautiful, these plants crowd the surface and block out light to the native species of plants below the surface. You can use a rake or a skimmer to remove the plants from the surface, but to truly remove the plant, you will need to remove the entire weed from the roots and dispose of it away from the shore. If fragments are left behind, the aquatic weeds will regrow and continue to reproduce.

Egeria Densa

Egeria Densa, also known as Brazilian Waterweed, is another invasive species. It has existed in US waterways since the late 1800's. Its ability to quickly spread and take over aquatic environments makes it a threat to our lake's native plants. Like the water hyacinth, Egeria Densa forms dense mats and limits the sunlight that penetrates into deeper parts of the lake. This affects the flow of water, the levels of oxygen in the water, and the fish and other creatures that live below the surface. To remove these plants, you will need to remove the entire weed, including the roots, and dispose of it somewhere away from the shore. 

Department of Boating and Waterways

For all areas outside of Willow Lake, the Department of Boating and Waterways is the only agency permitted to apply herbicides to kill aquatic plants. They spray annually to limit the growth of aquatic weeds. Spray treatment is typically performed in the early summer months. If you see a growing issue with aquatic plants in the open waterway, please reach out to the Department of Boating and Waterways.