LIHI Certificate #135 – Ladd’s Mill Project, Vermont

The Ladd’s Mill Project (the “Project”), exempted from licensing by the Federal Energy Regulatory Commission (“FERC”) as Project No. P-8242, is owned by Worcester Hydro Company, Inc. The Project is located on the North Branch of the Winooski River in the Town of Worcester, Washington County, Vermont. The Project is approximately five miles upstream form the Wrightsville Reservoir Dam and a total of ten miles upstream from the main trunk of the Winooski River proper. The Winooski River flows westward into Lake Champlain. Eventually, these waters drain into the St. Lawrence River, becoming the St. Lawrence Seaway, and into the Atlantic Ocean.

The major Project works consist of a dam and impoundment, an intake structure and a powerhouse. Specifically, the Project consists of: (1) a concrete gravity dam, 80 feet long with a height of 21 feet to the crest, with an elevation of 729.13 feet mean sea level (msl), with an additional 1 foot to the top of the flashboard elevation of 730.13 feet msl, creating a pond level 1-inch below that at 730.05 msl, (2) an impoundment approximately 1950 feet long, with a surface area of 4.57 acres and 16 acre-feet gross storage, (3) a concrete powerhouse with a turbine-generator capacity of 187 kW, (4) a 18.5-foot long forebay with a width of 9 feet and an average depth of 14.55 feet, (5) a 40 feet long by 25 feet wide tailrace, and (6) three 100 kVA transformers, which convert 480V three phase power up to 23.0 kV, which travels out on a 40 foot long transmission line to connect with the lines of Green Mountain Power.

The powerhouse, also concrete, is built into the eastern end of the dam. The plunge pool at the base of the dam is in constant communication with the minimum flow released from the weir, as well as the tailrace and downstream river flow.

The Ladd’s Mill Project is located about five miles upstream from another hydroelectric project on the North Branch, on Wrightsville Reservoir in Putnamville, VT. Above the Project are only the headwaters of the North Branch, with sparse development, a very rural character, and ultimately, near the top of the Worcester Range mountains, simply wild country.

Project Name Ladd's Mill
LIHI Certificate No. 135
LIHI Certificate Term March 17, 2017 - March 17, 2022
Owner Worcester Hydro Company, Inc.
State Vermont
Location Located at river mile 10 on the North Branch of the Winooski River in the town of Worcester, Washington County, Vermont.
Installed Capacity 0.172 MW
Average Annual Generation 440 MWh
Facility Type Run-of-river
FERC No. P-8242, exempt 1985

Certification History

July 26, 2017: Having received no requests for appeal of the preliminary decision to certify the Ladd’s Mill Hydroelectric project, Final Approval was effective on July 1, 2017. Ladd’s Mill is now LIHI Certification #135.

May 31, 2017: LIHI Executive Director Shannon Ames has announced a Preliminary Certification Decision that the Ladd’s Mill Hydroelectric Project (FERC No. P-8242) satisfies the LIHI Certification Criteria.

As provided for in Section 4.2.5 of the LIHI 2nd Edition Handbook, the Preliminary Certification Decision, along with the Application Reviewer’s report and (if prepared) report of the Executive Director, will be posted on the Institute’s Web page for 30 days.  Notice of the posting will be provided to all individuals or organizations that commented on the initial Application Package.

Any Commenter may submit a letter to the Executive Director requesting an appeal within the 30-day period which begins on June 1, 2017 and ends on July 1, 2017.  The appeal request must state specific reasons why the hydropower facility should have failed one or more criteria.  Only individuals or organizations that commented on the initial Application Package may file an appeal. 

If no appeal is requested within the 30-day period, the Executive Director will issue LIHI Certification for the facility and post a notification of certification on the Institute’s website.  Once final, the effective certification date for the Ladd’s Mill Project is March 17, 2017 for a five (5) year term, which will expire on March 17, 2022.

March 21, 2017: On March 17, 2017, the Low Impact Hydropower Institute (LIHI) received a complete application from the Worcester Hydro Company, Inc. for the Low Impact Certification of the Ladd’s Mill project, FERC No. 8242, located on the North Branch of the Winooski River in the town of Worcester, Washington County, Vermont.

LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Ladd’s Mill project meets the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook released in March 2016.  Please review the program and criteria in LIHI’s revised Handbook and then review the Project’s 2016 application materials posted on the project page.

Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc.) will be most helpful, but all comments will be considered.  Comments may be submitted to the Institute by e-mail at with “Ladd’s Mill Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, PO Box 194, Harrington Park, New Jersey 07640.  Comments must be received at the Institute on or before 5 pm Eastern time on May 20, 2017 to be considered.  All comments will be posted to the web site and the applicant will have an opportunity to respond.  Any response will also be posted.