The Middlebury Lower Project is located on the Lower Falls of the Otter Creek roughly one mile downstream from Middlebury village in the towns of Middlebury and Weybridge, in Addison County, Vermont. The impoundment extends almost 1.0 mile upstream to the Upper Falls at the center of Middlebury Village. The Sutherland Falls Project (FERC No. 2558) is located approximately 37 miles upstream, and the Beldens Project is located approximately 4 miles downstream.

Project Name Middlebury Lower
LIHI Certificate Number 99
LIHI Effective and Expiration Dates February 6, 2017
February 5, 2022
Owner Green Mountain Power Corporation
State Vermont
Location Located on the Lower Falls of the Otter Creek, roughly one mile downstream from Middlebury Village in the towns of Middlebury and Weybridge in Addison County, Vermont.
Installed Capacity 2.04 MW
Average Annual Generation 8,643 MWH
Facility Type Run-of-river
FERC No. 2737

Two concrete gravity dams impound the east and west river channels that diverge around a small island. The dam is 30 feet high and 478 feet long, with two ogee spillway sections, a 123-foot long western spillway section, and a 260-foot long eastern spillway section. The reservoir impounds 16 acres, with a normal water surface elevation of 314.5 feet above mean sea level (msl). The intake canal is 400 feet long, 40 feet wide, and controlled by a gate structure containing two 23-foot wide, 13-foot high gates.

The powerhouse is located at the downstream end of the intake canal, and equipped with steel trashracks having a 1.75 inch clear spacing. Three Francis turbine units provide a total installed capacity of 2.25 MW.  Generator leads and transformers connect the Project to the interconnected transmission/distribution system at the switchyard located 100 feet east of the powerhouse.

The Middlebury Lower Project is operated as a run-of-river facility. The impoundment elevation typically fluctuates not more than 1 inch from the crest elevation of 314.5 feet during normal operation, and water generally spills over the crest of the dam. Project operation relies upon inflows from upstream developments and the 628 square miles of the Otter Creek drainage basin.

Middlebury Lower east west dams

Middlebury Lower – east and west dams

Middlebury Lower powerhouse

Middlebury Lower Powerhouse

Certification History

May 15, 2019: The decision to recertify the Middlebury Lower Hydroelectric Project is final. No appeals were received during the appeal period which closed on May 11, 2019. The new certification term for the Project is from February 6, 2017 through February 5, 2022.

April 10, 2019:  The Low Impact Hydropower Institute (LIHI) has preliminarily approved Low Impact Certification for the Middlebury Lower Hydroelectric Project, LIHI Certificate #99 for a new 5-year term with the following condition:

Condition 1: The Facility owner shall refine the Project’s operations plan in consultation with VDEC to seek to minimize the effects of Project shutdown on head pond fluctuation and spill rates, and shall develop drawdown rate procedures for water level and flow management during maintenance and repair activities for the protection of state-listed freshwater mussel species.  The revised operations plan shall be submitted to LIHI within 60 days of approval.  If consultation and plan refinement are not completed by December 31, 2019, the Facility owner shall provide a status update in annual compliance submittals to LIHI.

This decision is preliminary pending the 30-day appeal window. Only those who commented on the initial application during the 60-day comment period are eligible to file an appeal. Such appeal needs to include an explanation as to how the Project does not meet the LIHI criteria. Appeal requests can be submitted by email to comments@lowimpacthydro.org with “Middlebury Lower Hydroelectric Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Ave, Suite 6, Lexington, MA 02420. All requests will be posted to the website.  The applicant will have an opportunity to respond and any response will also be posted. Requests must be received by 5 pm Eastern time on May 11, 2019.  The full application and reviewers report are available below.

November 12, 2018: The Middlebury Lower Hydroelectric project has been granted another extension of the current certificate term. The new expiration date is March 31, 2019.

June 11, 2018: The Middlebury Lower Hydroelectric project has been granted another extension of the current certificate term. The new expiration date is December 31, 2018.

August 31, 2017: The Middlebury Lower Hydroelectric project has been granted another extension of the current certificate term. The new expiration date is March 31, 2018.

May 17, 2017: LIHI has received an application for a new term of Low Impact Certification for the Middlebury Lower Hydroelectric project.  LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Middlebury Lower 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 comments@lowimpacthydro.org with “Middlebury Lower 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 July 16, 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.

December 16, 2016: The Middlebury Lower Hydroelectric project has been granted an extension of the current certificate term. The new expiration date is August 6, 2017. See extension letter for explanation below.

November 29, 2012: The Middlebury Lower Project has been certified as low impact for a five-year term, effective February 6, 2012 and expiring February 6, 2017.

April 6, 2012: Public comment period on application has closed.

February 6, 2012: Central Vermont Public Service (CVPS) has submitted an application for the certification of its Middlebury Lower Project. Public comment period on application has opened.

 


Files:

2017-2019 Re-certification

2012 Certification