LIHI Certificate #158 – Chasm Project, New York

The Chasm Hydroelectric Project, located at river mile 28.8 on the Salmon River near the Town of Malone in Franklin County, New York, and is the fourth hydroelectric project upstream from the mouth of the river. From its headwaters in the Adirondack Mountains, the Salmon River flows approximately 50 miles northwest to its confluence with the St. Lawrence River near Dundee, Quebec.

The Project was originally constructed in 1913 and is owned by Erie Boulevard Hydropower, LLC (Brookfield Renewable Energy Group). It was most recently relicensed by FERC in 2015.

The Project consists of the Chasm Falls dam, a 202-foot-long and 32-foot-high concrete gravity-type dam that includes a 100-foot long spillway section. The dam impounds a 22-acre reservoir. A 22-foot-long intake section and 7-foot diameter steel pipeline 3,355 feet long convey water from the impoundment to the powerhouse. The penstock is above ground for the first 100+ feet downstream of the intake, then buried thereafter. The powerhouse contains three Francis units with a total capacity of 3.35 MW. The tailrace is 850 feet long and about 20 feet wide. The Project creates a 4,800-foot-long bypassed reach. Approximately 500 feet downstream from the confluence of the bypassed reach and the tailrace is the Chasm Falls Recreation Area, a seasonal day use area owned and maintained by Erie. There is also an informal bypassed reach access area near the powerhouse.

The Project is operated in a run-of-river mode with a 0.25‐foot drawdown limit measured in a downward direction from top of crest or the 2‐foot‐high flashboards (when installed) when river flows exceed 85 cfs. Impoundment fluctuation is limited to 0.1‐foot measured in a downward direction from top of crest or 2‐foot‐high crest control devise (when installed) when river flows are less than 85 cfs. The reduced reservoir fluctuation is implemented to support downstream habitat areas in the event of a potential unit trip during non-spill events.

The FERC license requires the Licensee to provide 15 cfs to the bypassed reach year-round from the date of license issuance and then, within 48 months of license issuance, or by October 2, 2019 (whichever occurs later) implement seasonal minimum flows of 15 cfs from May 1 through October 1, and 23 cfs from October 2 through April 30.

Project Name Chasm
LIHI Certificate No. 158
LIHI Certificate Term April 26, 2019 - April 25, 2024
Owner Brookfield Renewable Energy Group
State New York
Location River Mile 28.8 on the Salmon River
Installed Capacity 3.35 MW
Average Annual Generation 10,210 MWh
Facility Type Run of river
FERC No. P-7320 issued 2015, expires 2045

Certification History

September 4, 2019: The decision to certify the Chasm Hydroelectric Project is final. No appeals were received during the appeal period which closed on August 22, 2019. The certification term for the Project is from April 26, 2019 through April 25, 2024.

July 22, 2019:The Low Impact Hydropower Institute has preliminarily approved Low Impact Certification for the Chasm Hydroelectric Project.

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 with “Chasm 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 August 22, 2019.  The full application and reviewers report are available below.

If no appeal requests are received and the decision becomes final, the Certification term for the Project (pending LIHI #158) will be April 26, 2019 for a term of five (5) years, which will expire on April 25, 2024.

April 30, 2019: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Chasm Hydroelectric Project.  LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Project meets the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook.  Please review the program and criteria in LIHI’s revised Handbook and then review the Project’s application materials below.

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 “Chasm Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Avenue, Suite 6, Lexington, MA 02420.  Comments must be received on or before 5 pm Eastern time on June 29, 2019 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.