Union Gas

Union Gas

The Union Gas Hydroelectric facility is located on Messalonskee stream in Waterville, Maine. The Union Gas project is the one of four hydropower facilities between Messalonskee Lake dam and the Kennebec River. Three of these facilities, Union Gas, Rice Rips, and Oakland, are currently licensed under FERC project No. 2556. The Union Gas facility is approximately 1 mile upstream from the confluence of Messalonskee Stream withmain stem of the Kennebec River. The next facility is approximately 1.6 miles upstream andis known as the Automatic project. The Automatic facility is currently owned and licensed separately from the three other hydropower dams on Messalonskee Stream. The Union Gas impoundment reaches upstream to a set of rips approximately 1000 feet below the Automatic project dam. The Automatic impoundment stretches upstream approximately 4.5 miles to the tail race of the Rice Rips facility, which is the next hydropower facility upstream. This effectively results in approximately 0.3 miles of non impacted stream between the Union Gas and Rice Rips facilities.

Project Name Union Gas
LIHI Certificate Number 58
LIHI Effective and
Expiration Dates
May 9, 2015
May 9, 2020
Owner Messalonskee Stream Hydro Associates
State Maine
Location Located on the Messalonskee Stream, a tributary of the Kennebec River, in Kennebec County, Maine.
Installed Capacity 1.5 MW
Average Annual Generation 4.3 GWh
Facility Type Inflow > 570 cfs: run-of-river
Inflow < 570 cfs: cycled
FERC No. 2556

The Union Gas facility operates with an installed electrical generating capacity of 1.8 MW. The facility is comprised of a 343 foot-long dam that is 31 feet high with 18 inch flashboards. The facility impoundment is approximately 1.5 miles long with a usable storage capacity of 30 acre-feet. Another hydropower dam that is a component of what is known as the Automatic hydropower facility is located between the Union Gas facility and the Rice Rips facility.

Certification History

May 2, 2016: LIHI Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has certified that the Union Gas Hydroelectric Project (FERC No. P-2556) satisfies the LIHI Certification Criteria. A Preliminary Decision was announced on April 1, 2016, and a 30-day appeal period was open through May 1, 2016. No requests for appeal were received. This Certification Decision includes one facility-specific condition, as follows:

  • Condition 1: On the Owner’s Annual Compliance Statements, the Owner will update LIHI the status of downstream eel passage at the site. The Owner will notify LIHI within 45 days of when DMR determines there is a sufficient number of eel to present in the river to conduct the studies needed to determine the best location to install downstream passage. A summary of those study results, along with a DMR approved plan and schedule for downstream eel passage installation, shall be included in that year’s Annual Compliance Statement.

The effective certification date for the Union Gas Project is May 9, 2015 for a five (5) year term, which will expire on May 9, 2020.

December 4, 2015: LIHI has received a comment letter from the Maine Department of Marine Resources in support of the recertification of the Union Gas project. The comment may be found in the Files section below.

November 24, 2015: The Low Impact Hydropower Institute has received a complete application for a new term of Low Impact Certification for the Union Gas Hydroelectric project.  The application materials can be found in the Files section below.

The public comment period for this application closed on January 23, 2015.

June 19, 2015: The Union Gas Project has been granted an extension of the current certificate term. The new expiration date is December 31, 2015. See ExtensionLetter_2015Recert for explanation below.

October 22, 2010: The Union Gas Project has been certified as low impact for a five year term, effective May 9, 2010 and expiring May 9, 2015.

July 9, 2010: The public comment period for the application for certification has been closed.

May 9, 2010: Messalonskee Stream Hydro Associates has submitted an application for certification of the Union Gas Hydroelectric Project. A public comment period will remain open for 60 days.


Files: