NH1

The Dodge Falls Associates hydroelectric facility (the DF Facility) is located at river Mile 268 on the Connecticut River in the towns of Bath, New Hampshire and Ryegate, Vermont. The hydroelectric station was constructed at the site of the existing Dodge Falls dam. The dam (“DF dam” or “Ryegate dam”) was used until 1966 to provide waterpower to a paper mill located on the Vermont side of the river. From 1966 until 1990 process water was supplied to the paper mill with excess flow discharged over the dam. When the Dodge Falls project began operation in 1990, most of the river flow then was used for hydroelectric generation with the paper mill receiving up to 5 cfs for process use. In 2000 the paper mill was shut down and papermaking machinery was removed from the mill. The dam is 485 feet long and consists of a grouted, rock fill, timber crib with a timber crest and wood plank facing. The crest elevation of the dam is 421.4 feet NGVD and is about 15.5 feet above the bedrock streambed at the downstream toe. Initially the project was authorized to install 2 feet of pin supported wooden flashboards to reestablish the historic level of the impoundment.

Project Name Dodge Falls
LIHI Certificate Number 42
LIHI Effective and
Expiration Dates
June 1, 2014
June 1, 2019
Owner Dodge Falls Associates, LP
State New Hampshire, Vermont
Location Located at river mile 268 on the Connecticut River in the towns of Bath, New Hampshire and Ryegate, Vermont.
Installed Capacity 5.0 MW
Average Annual Generation 26.0 GWh
Facility Type Run-of-river
FERC No. 8011

In 1988 construction began on the DF project and was completed in 1990. The DF project consists of a reinforced concrete powerhouse located on the New Hampshire side of the river with a 75-foot side concrete spillway constructed on the right side of the fore bay. The spillway is connected to the timber crib dam.

The DF project was operated from 1990 to 1993 using pin supported wooden flashboards. In 1993 a two-foot rubber pneumatic flashboard system was installed on the concrete spillway to replace a portion of the pin supported wooden flashboard system. In 1997 a two-foot rubber pneumatic flashboard system was installed on the timber crib dam to replace the remaining wooden flashboards. A single double regulated 5000 kW Escher Wyse turbine, rated at 12 feet of head and a flow of 5800 cfs, is installed in the powerhouse.

The DF Facility is operated as a run of river facility. Reservoir level is maintained by means of a pond level control system. The project is required to maintain a minimum flow of 1108 cfs (0.5 csm) or project inflow, whichever is less. The DF Facility is located immediately downstream of the Fifteen Mills Falls Hydroelectric Project (“the FMF project”) (FERC # 2077). The FMF project consists of three separate dams and powerhouses located upstream from the DF project. The closest FMF project, the McIndoes power station, is located approximately 4 miles upstream of the DF project. Since the DF project is a run of river project, available river flow for the DF project is determined by discharge from the McIndoes project.

The project is operated as a strict run of river facility. Reservoir level is maintained at the top of the flashboards through operation of a pond level control system. The project is required to maintain a minimum flow of 1108 cfs (0.5 csm) or project inflow, if less.

Project inflow is controlled by the flow discharged from the McIndoes hydroelectric station, a part of the Fifteen Mile Falls Project (FERC #2077). The station is located approximately 4 miles upstream from the Dodge Falls dam. At the time the DF project was licensed and constructed the McIndoes station did not have a minimum flow discharge requirement. From commencement of generation at Dodge Falls in 1990 until 2003, inflow to the Dodge Falls reservoir periodically was interrupted during ponding periods at the McIndoes project. The Dodge Falls project would note a decrease in pond level and the turbine generator would be shut down until inflow was restored by the McIndoes project. The water quality certificate issued to the Dodge Falls project recognized the effect the McIndoes project would have on the operation of the Dodge Falls project and allowed a reservoir draw down of up to 3.0 inches to accommodate the frequent fluctuations in McIndoes station flow discharge. During shutdown periods a continuous flow of 530 cfs was required to be maintained below the project until the reservoir level was built up to reestablish turbine operation and or spillage.

The Fifteen Mile Falls project was relicensed in 2002. Under the new license the McIndoes station is required to maintain a minimum flow that varies during the year. From June 1 through September 30 McIndoes is required to maintain a discharge of 1,105 cfs, or inflow, whichever is less. From October 1- March 31 the minimum flow is 2,210 cfs, or inflow, whichever is less. From April 1 – May 31 the minimum flow is 4,420 cfs, of inflow, whichever is less. This had had a direct effect on DF project operations. The Dodge Falls project now operates strictly as a run-of-river project. Because the minimum flow from the McIndoes station now is greater than the minimum flow shutoff point of the Dodge Falls turbine, the turbine is able to operate continuously and no longer needs nor uses the 3-inch draw down permitted in its Water Quality Certification When the Dodge Falls turbine is shutdown, river inflow is discharged over the pneumatic flashboards.

NH2

Certification History

June 3, 2015: Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has determined that the Dodge Falls Hydroelectric Project (FERC No. 8011) satisfies the LIHI Certification Criteria. The effective certification date for the Dodge Falls Project is June 1, 2014 for a five (5) year term, which will expire on June 1, 2019, with the following condition:

  • Condition 1. The facility owner shall consult with the NHDES to develop a water quality monitoring plan to define current water quality conditions at the Dodge Falls dam and powerhouse, shall implement that plan, and shall report the results to NH DES and to LIHI within six months of the date of recertification. If the facility is found to be the cause of any violations of state water quality standards, the facility owner shall notify LIHI within 30 days of such a finding and shall develop a remediation plan to correct the violations. LIHI reserves the right to suspend or rescind its certification if successful remediation is not implemented.

September 5, 2014: The Low Impact Hydropower Institute (LIHI) received an application for a second term of Low Impact Certification of the Dodge Falls Hydroelectric Project, FERC #8011, located on the Connecticut River in Vermont. The current Certificate term expired June 1, 2014, but an extension of the term has been granted through December 31, 2014 to allow for administrative processing and public comment.

The 2014 Dodge Falls application materials are available below.

August 29, 2009: The Dodge Falls Project has been certified as low impact for a five year term, effective June 1, 2009 and expiring June 1, 2014.

June 1, 2009: Dodge Falls Associates, LP has submitted an application for certification of the Dodge Falls Hydroelectric Project. A public comment period for the application will remain open for 60 days.


Files: