The 19.4MW Worumbo hydroelectric project in Maine, US, has become the tenth project nationwide to be certified as low impact by the Low Impact Hydropower Institute (LIHI).
The Project, located on the Androscoggin river at Lisbon Falls, Maine, is owned and operated by the Miller Hydro Group, and licensed by the Federal Energy Regulatory Commission (FERC). It is the first hydro power facility to earn LIHI certification in Maine.
The LIHI certification program is relatively new, having certified its first plant in March 2001. The Institute’s voluntary certification programme is designed to help consumers identify environmentally sound, low impact hydro power facilities for emerging ‘green’ energy markets. While some hydro power plants will not qualify, the certified total is expected to grow significantly.
‘We are pleased to see a Maine hydro project join the ranks of LIHI certified facilities,’ said Richard Roos-Collins, chair of LIHI’s Governing Board, ‘and I hope that other Maine facilities will follow Miller Hydro Group’s lead.’ Asked if he thought other Maine projects would seek Low Impact certification, Fred Ayer, LIHI’s Executive Director responded: ‘Yes, it is clear to me that there is a growing interest and demand for green electricity products in Maine. If you couple that with the fact that Maine has a large number of recently relicensed hydro projects, it seems to me it then only becomes a question of certifying the supply to meet the growing demand – and LIHI is ready to certify more Maine projects that meet the Institute’s criteria.’
When asked about the significance of the Worumbo certification, Mark Isaacson, Vice President of Miller Hydro Group said: ‘We are delighted to be certified by the Low Impact Hydro Institute and hope this certification will lead to an expansion of the market for green electricity in New England.’
The Worumbo project consists of a dam/spillway, with a crest elevation of 97 mean sea level (msl) which includes a gated flood spillway, an ogee spillway with a 0.6m high hinged flashboards, a center rock ledge section containing a concrete dike with 0.6m high hinged flashboards, and a 158.5m long rock-filled timber crib dam with 0.46m high pneumatically operated crest gates; an intake section and integral power house with two turbine generators units having a rated capacity of 19.4MW at an operating head of 9.3m. The crest gate/flashboard system is designed to fail when overtopped by two feet of water. The dam creates an impoundment with a surface area of 76.8ha at a normal full pond elevation of 98.5msl.
The project is currently operated as a run-of-river project with outflow approximately equal to inflow on an instantaneous basis. The project is also operated to provide seasonally-varied minimum flow releases into the 259m long bypassed river reach between the Durham side dam and the end of the tailrace training wall. Current operation permits the impoundment to be drawn down by a maximum of 0.46m. Minimum flow release from the project is maintained at 48m3/sec or inflow, whichever is less, during impoundment refilling.
The Worumbo project meets LIHI’s eight environmentally rigorous Low Impact criteria addressing river flows, water quality, fish passage and protection, watershed health, endangered species protection, cultural resources, recreation use and access, and whether or not the dam itself has been recommended for removal.
Worumbo successfully completed LIHI’s application process, which includes a public comment period, review by an independent technical consultant, consultations with state and federal natural resource agencies, and evaluation by the LIHI Governing Board, including leaders in the river conservation and renewable energy fields. The Board’s vote to certify the Worumbo Project was unanimous.
For further information about the Worumbo Project, or any of the other projects certified as Low Impact, please contact Fred Ayer, LIHI Executive Director at (207) 773-8190, or visit the LIHI website by clicking on the link below.