LIHI Certificate #95 - Passumpsic Project, Vermont
The Passumpsic Project is the furthest downstream of the four CVPS Projects on the Passumpsic River. It is located approximately 1.7 miles downstream of the Gage Project, at river mile 5.5. It was built in 1905-1906 for the St. Johnsbury Electric Company. The powerhouse was completely destroyed in the flood of 1927. Portions of its foundation and those of its associated power canal remain buried on the other side of the existing canal. The plant was rebuilt in 1929 in the location of the Chase leatherboard mill water wheel, which was also destroyed in the flood. The building behind the powerhouse (not owned by CVPS) is the remainder of the former leatherboard mill.
The Project impounds an 18.3-acre reservoir which extends 4,600 feet upstream with a water surface elevation of 521.0 feet msl and a usable storage of 18.4 acre-feet. The concrete gravity dam consists of two sections: (1) a south section 122 feet long by maximum height of 10 feet, with a crest elevation of 519.98 feet msl and topped with 1-foot-high flashboards; and (2) a north section 126 feet long by maximum height of 10 feet, with a crest elevation of 519.98 feet msl topped with 1-foot flashboards. The dam is equipped with a 27-foot wide headgate structure with two gates. The power canal conveys flow to the powerhouse via an integral intake with an inclined trashrack. The canal is 19 to 22 feet wide and 87 feet long. There is also a sluice and a 24-foot long overflow spillway. The powerhouse contains one vertical shaft turbine rated at 708 kW and a generator rated at 700 kW, as well as appurtenant equipment. A substation is located adjacent to the power canal. The downstream fish passage facility consists of a sluiceway in the spillway adjacent to the canal headworks. The bypassed reach is about 350 feet long. The project has a hydraulic range of 195 to 460 cfs and an average annual generation of about 2,000 MWh.
|LIHI Certificate No.||95|
|LIHI Certificate Term||February 6, 2017 - February 5, 2022|
|Owner||Green Mountain Power Corporation|
|Location||Located at river mile 5.5 on the Passumpsic River, a tributary of the Connecticut River, approximately 1.7 miles downstream of the Gage Project.|
|Installed Capacity||0.7 MW|
|Average Annual Generation||1,998 MWH|
|FERC No.||P-2400 issued 1994, expires 2034|
Certification HistoryOctober 10, 2018: The decision to recertify the Passumpsic Hydroelectric Project is final. No appeals were received during the appeal period which closed on October 6, 2018. The new certification term for the Project is from February 6, 2017 through February 5, 2022. September 6, 2018: On September 4, 2018, the Low Impact Hydropower Institute (LIHI) preliminarily approved the Passumpsic Hydroelectric Project for a new 5-year term of Low Impact Certification, with the following conditions:
- Condition 1: The Owner shall provide LIHI with evidence that FERC has approved the Revised Flow Management Plan (filed by GMP on April 25th, 2018) within 60 days from the date of issuance of that approval.
- Condition 2: The Owner will provide LIHI with evidence that FERC has approved the Downstream Fish Passage and Operations and Maintenance Plan (filed by GMP on April 25th, 2018) within 60 days from the date of issuance of that approval. If FERC issues new terms and conditions, the LIHI Certification is subject to amendment to incorporate such terms and conditions.
- Satisfied in 2018. Condition 3: The Owner shall provide a LIHI with a copy of the final report to FERC demonstrating the completion of the portage pathway improvements within 60 days of filing that report with FERC.