The Presence of the Waterweed Hydrilla in Swift Creek Reservoir September 23 2009

What is Hydrilla? Non-native invasive water plant indigenous to Asia/Africa First appeared in U.S. waters around 1960 in Florida from discarded aquarium plants Common and pervasive in lakes and reservoirs throughout the U.S. Could be considered an aquatic version of Kudzu. Many similarities…native to Asia, Rapid Growth Rate, Problematic

Hydrilla Ecology Rooted aquatic plant that forms dense surface mats Rapid growth (up to one inch/day) Grows in depths ranging from one inch to 20 feet Reproduces by seed, fragmentation and runners Often introduced to lakes and reservoirs on boats and trailers Comparatively, the Kudzu plant has a documented growth rate of up to a foot per day

Hydrilla Characteristics Spiny leaves that circle the stem Adapted for photosynthesis in low light Efficient use of available nutrients Hardy - Over winters as a perennial Can out-compete native species of plants

Brandermill Woolridge Road Woodlake Hull Street Road

Current Situation Not impacting source water quality for treatment Some die-off expected during Winter Concern that growth next year may increase substantially Increased growth may be detrimental to recreational use and treatability

Response Plan to Date Chesterfield County Department of Utilities and Environmental Engineering Staff conducted an initial survey of the extent of the growth (August 20th 2009) Consultant contacted and Scope of Services for Best Management Strategies has been submitted for review by Utilities Members of consulting staff are leading professionals in aquatic plant control as related to water treatment