Hydrilla Management - DEP

Environmental Protection


Science & Research

Invasive Species


Hydrilla Management

Hydrilla (Hydrilla verticillata) is an invasive aquatic plant from Asia. It forms into dense mats that:

grow where no other plants can grow (in pratically all conditions)

spread by fragments, tubers and seed-like winter buds

exacerbate the growth of algae

block out native species

harm fisheries by cosuming disolved oxygen

interfere with areas that are traditionally used for recreation

obstruct the operation of drinking water infrastructure

Download the Hydrilla FAQs

Prevent the Spread of Hydrilla

While boating or fishing in the watershed, we encourage you to:

avoid passing through it by boat to keep it from spreading

clean your gear thoroughly to keep it out of new waterbodies

Submit an Invasive Species Report Form if you think you’ve seen it

Visit Invasive Species to learn more.

Hydrilla Infestation at New Croton Reservoir

We are collaborating with New York State to manage an infestation of hydrilla at New Croton Reservoir and downstream in the Croton River. If left unchecked at New Croton Reservoir, hydrilla has the potential to spread throughout the region and affect other waterbodies.

Download the Hydrilla Management Plan

Download the Map of Hydrilla Distribution and Study Sites in New Croton Reservoir

Visit the NY State Department of Environmental Conservation Croton River Hydrilla Control Project

Expert Panel Report on Hydrilla Management

Together with the Water Research Foundation, we assembled an expert panel that reviewed plans to manage the infestation at New Croton Reservoir. Based on the panel’s advice, we are piloting a program to remove this invasive plant from the reservoir and solidify a control strategy that will expand to the entire infestation in the reservoir in the years ahead.

Download the Expert Panel Report: Chemical Management of Hydrilla for Drinking Water Utilities