Connecticut River Hydrilla Research & Demonstration Project

USACE Demonstration Project

The USACE demonstration project seeks to determine the effectiveness of herbicides registered for aquatic use by the U.S. Environmental Protection Agency to safely reduce and control the spread of hydrilla in the Connecticut River. The project will investigate hydrilla’s growth patterns, water exchange dynamics in the Connecticut River, and evaluate herbicide efficacy in laboratory conditions to guide operational scale field demonstrations of herbicide efficacy.

Appropriations and Authority

Funding for the USACE Connecticut River Hydrilla Demonstration Project was made available through a Fiscal Year 2023 and 2024 Congressional Energy and Water Development appropriations.

“The Corps of Engineers is authorized to treat Hydrilla (Hydrilla verticillata) under Section 104 of the River and Harbor Act of 1958, through the Aquatic Plant Control Research Program. Funding for the project is available through the Corps of Engineers Aquatic Plant Control Research Program”  8  .

Goals and Objectives

Project Goal: Protect and restore the Connecticut River, its tributaries, and associated ecological and economic benefits from hydrilla invasion impacts.

Project Objectives

  1. Implement science that protects public and environmental safety
  2. Conduct research to develop and evaluate best management practices
  3. Technology transfer of best management practices

USACE Actions

  1. Public engagement, stakeholder notification, and coordination
  2. Environmental and technical studies to guide site selection and treatment plan development
  3. Environmental permitting at the federal, state, and local levels
  4. Field demonstration and evaluation

Site Selection

Sites included in this demonstration project were selected based on the degree of hydrilla infestation, owner/manager interest in project participation, and potentially suitable treatment conditions. Selection was made in conjunction with CAES.

Project Timeline

Timeline of USACE Demonstration Project

Environmental Assessment (National Environmental Policy Act)

In accordance with the National Environmental Policy Act, an Environmental Assessment was prepared in 2024 and a Finding of No Significant Impact (FONSI) was signed in July 2024.

State Permitting

A Connecticut Department of Energy & Environmental Protection (DEEP) herbicide application and Connecticut Natural Diversity Data Base review were completed in 2024. Permits were issues and treatments done at five sites July-Aug 2024 (Keeney Cove, Portland Boat Works, Chapman Pond, Chester Boat Basin, and Selden Cove).

CT River Hydrilla Demonstration Project USACE Project Delivery Team

Connecticut River Hydrilla Demonstration Project USACE Project Delivery Team, April 2023

U.S. Army and USACE logos

Demonstration Sites:

Map of demonstration sites

Timeline of USACE Demonstration Project

Connecticut River Hydrilla Demonstration Project USACE Project Delivery Team, April 2023