LIHI Certificate #116 – Holtwood Project, Pennsylvania



Project Name Holtwood
LIHI Certificate No. 116
LIHI Certificate Term
January 20, 2022 – January 19, 2035
Owner BIF III Holtwood, LLC, a subsidiary of Brookfield Renewable Energy Group
State Pennsylvania
Location Located on the Lower Susquehanna River at approximately River Mile 25, in Lancaster and York counties in south-central Pennsylvania.
Installed Capacity 252 MW
Average Annual Generation 924,436 MWh
Facility Type limited store and release
FERC No. P-1881 issued in 1980, expires 08/31/2030

The Holtwood Project is located on the Lower Susquehanna River in Lancaster and York Counties in south-central Pennsylvania. The Project is situated approximately seven miles north of the Pennsylvania/Maryland border, and is one of five hydroelectric projects located along the lower Susquehanna River. Four of these projects are mainstem dam projects and one, Muddy Run, is a pumped storage station that uses the Conowingo Pond as its lower storage pond. Moving from upstream to downstream, these Susquehanna River hydroelectric projects are: York Haven, Safe Harbor, Holtwood, Muddy Run Pumped Storage Project, and Conowingo.

The dam and project were constructed in 1905 and began commercial operation in 1910. A new powerhouse and generating units went into service in 2013.

The dam is an overflow-type structure that consists of a 2,368-foot-long by 55-foot-high, low hazard, concrete gravity dam. The top of the dam is raised 4.75 feet to an elevation of 169.75 feet via the use of wooden flashboards and inflatable rubber dam sections. A skimmer wall located on the upstream side of the forebay protects the powerhouse from debris. The forebay was expanded and the skimmer wall was replaced as part of the redevelopment project.

Downstream of the dam, a diversion wall connects the western side of the original powerhouse to a long, narrow river island known as Piney Island, and effectively separates the tailrace from the remainder of the Susquehanna River. Along the western shore of Piney Island, another narrow channel is formed between Piney Island on the east and a series of smaller islands on the west; this channel is referred to as Piney Channel. Excavation in both the tailrace and Piney Channel reduced back pressure on the generating units and improved fish passage. The remainder of the Susquehanna Riverbed is referred to as the spillway.

The two Project powerhouses are located on the east side of the river along the Lancaster County shoreline. The original powerhouse contains ten similarly sized vertical Francis turbine/generators and two smaller vertical Francis turbine/generators, with a combined installed capacity of 171.4 MW. The new powerhouse contains two vertical Kaplan turbine generating units with a combined capacity of 80.6 MW.

The project impounds Lake Aldred, a 2,600-acre reservoir. The project operates in a limited store and release mode and supplies a continuous 200-cfs minimum flow to Piney Channel to provide suitable habitat for resident fish species. Additionally, the project provides a continuous base flow of 800 cfs and a daily volumetric flow equivalent either to 98.7% of the inflow requirements of the downstream Conowingo Project or to the daily net inflow to Lake Aldred, whichever is less. The flow regime was established in coordination with the other Susquehanna River projects through agency consultation. The agencies involved include: PA Department of Environmental Protection, PA Fish and Boat Commission, PA Department of Conservation and Natural Resources (DCNR), Susquehanna River Basin Commission, Maryland Department of Natural Resources, U.S. Fish and Wildlife Service (USFWS), the U.S. Army Corps of Engineers, and FERC.

Dissolved oxygen concentrations are of concern in the project area but DO monitoring results found that concentrations generally fall within prescribed parameters except occasionally during some low inflow periods. A 10-inch pipe through the dam delivers water to the spillway area to provide a source of fresh, oxygenated water. The 200-cfs minimum flow helps protect water quality in Piney Channel by preventing isolated pools from forming which would otherwise deplete DO concentrations.

Upstream fish passage facilities include a tailrace fish lift with two entrances and a spillway lift that are operated from April 15 – June 15 and from September 1 – October 15, or as recommended by the resource agencies. The two upstream lifts have their own fish handling systems that sluice fish into a common flume through which fish swim into Lake Aldred. The lifts or “hoppers” raise the water (and fish) entering the facility about 50 feet to the level of the forebay. Fish swim through the flume and enter the lake outside the plant skimmer wall. The project must pass 75% of American shad that pass through downstream Conowingo facility and 50% must successfully pass within 5 days of leaving Conowingo, although this goal has not yet been achieved and studies are ongoing and modifications being made to improve the fish lift. American eel do not currently have access to Project waters due to a lack of upstream passage at Conowingo.

Fish pass downstream via the turbines or spillway. Enhancements included excavation to significantly minimize velocity barriers to migrating fish. Downstream fish passage will be evaluated through testing once upstream passage has improved. The project must achieve a 95% successful downstream passage rate for juvenile shad and 80% for adult shad.

The project operates under a Land and Shoreline Management Plan. The plan commits the project owner to continued land preservation and maintenance of a shoreline buffer zone as well as buffers on tributaries in the project area. The management plan further promotes the development of recreation opportunities with consultation from recreation organizations in the area.

PLUS-Standard: The project has a dedicated buffer zone for conservation purposes which extends 200-feet from the average annual high-water line for at least 50% of the shoreline.  The project owner transferred nearly 2,000 acres of the project land to the Lancaster County Conservancy, York County, and the Conservation Society of York County. The owner makes annual contributions to the Lower Susquehanna Fund, which was established to provide revenue to protect, operate, maintain, improve, and promote the conserved properties.

Threatened and endangered species potentially present at the project include Indiana bat and Northern long-eared bat.  Two plant species, sticky goldenrod and white doll’s daisy are found throughout the spillway and below the dam.  The project owner monitors both species and submit data to DCNR. Project flow regimes mentioned above were developed to protect these populations. Mitigation plans were developed with consultation with USFWS and Pennsylvania Game Commission.

The Holtwood project itself, including the original powerhouse and dam, is eligible for inclusion in the National Register of Historic Places due to its importance in the development of hydroelectric power on the Susquehanna River, its engineering significance as the location of the first Kingsbury thrust bearings, and as an example of Classical Revival architectural style. The project owner developed a Historic Properties Management Plan. A segment of the historic Susquehanna and Tidewater Canal Lock No. 12 has been preserved and interpretive displays denoting its operation and significance are provided. The project must avoid development in the vicinity of Upper Piney Island due to the archaeological resource potential.

Recreational resources at the project include picnic areas, hiking trails, camping areas, fishing access points, boat ramps, and a whitewater boating features park that operates 264 hours per year. Flow forecast information is provided via Public access is provided free of charge.

Compliance Status

The Certificate includes the following facility-specific conditions:

Condition 1:   Since the Project will begin relicensing during the new LIHI Certification term, the facility Owner shall provide to LIHI as part of the annual compliance report, a status report on the FERC licensing progress listing significant agency interactions that have occurred in the past year that are relevant to any LIHI criteria and highlighting major topics of agreement or disagreement.  LIHI reserves the right to request additional details, if necessary, if highlighted topics are relevant to the LIHI criteria and their associated goals. LIHI also reserves the right to modify the Certificate conditions again if needed.

Condition 2: In annual compliance reports to LIHI, the facility Owner shall provide a summary  of the status on progress toward meeting fish passage targets including: a) the status of fishway operations and agency-recommended fish passage facility improvements; b) re-initiation of the Tier II telemetry study, study results when available, and agency comments on them; c) any efforts made to investigate methods to sort and remove invasive fish species; d) zone of passage improvements including removal of excess material in the tailrace; e) the status, results, and agency comments on the planned turbine survival study; and f) a summary of the annual Fish Passage Technical Advisory Committee meetings and any other agency consultation related to fish passage.

Condition satisfied in 2023. Condition 3:  In annual compliance reports to LIHI, the facility Owner shall provide a summary of results from the ongoing monitoring for White Doll’s Daisy and Sticky Goldenrod, and any agreements reached with DCNR regarding changes in monitoring scope or frequency.

2023: No material changes or compliance issues were identified. The project remains in compliance based on the annual review. For Condition 1, the project reported no relicensing activity yet. For Condition 2 the project submitted annual reports and meeting notes, and reported that resource agencies continue to defer fishway operations and studies due to the invasive snakehead and catfish species.  For Condition 3, the project reported completion of the 2022 monitoring studies and submitted documentation of PA DCNR’s determination that monitoring could be discontinued, thus satisfying the condition.

2022: No material changes or compliance issues were identified. The project remains in compliance based on the annual review. For Condition 1, the project reported no relicensing activity yet. For Condition 2 the project reported filing of the 2021 annual reports and meeting notes, and reported that resource agencies continue to defer fishway operations and studies due to the invasive snakehead fish.  For Condition 3, the project reported completion of the 2022 monitoring studies with reports not yet available.

Certification History

May 27, 2022: The Low Impact Hydropower Institute has issued a final decision on the recertification of the Holtwood Project.  The 30-day appeal window closed on May 25, 2022 and no appeals were filed.  Therefore, the decision to recertify the project is now final.  The new term is January 20, 2022 through January 19, 2035 in accordance with the term extension that became effective January 1, 2022 in Revision 2.05 of the LIHI 2nd Edition Certification Handbook.

April 25, 2022: The Low Impact Hydropower Institute (LIHI) has preliminarily approved the Holtwood Project for a new 13-year term of Low Impact Certification. The full application and reviewer’s report are available below. 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 “Holtwood Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Ave, Office 407, Arlington, MA 02476. 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 May 25, 2022. If no appeal requests are received and the decision becomes final, the Certification term for the Project will be January 20, 2022 through January 19, 2035.

February 3, 2022: The Low Impact Hydropower Institute (LIHI) has received a complete recertification application from BIF III Holtwood, LLC (a subsidiary of Brookfield Renewable Energy Group) for the Holtwood Project. The complete application can be found below. LIHI is seeking comment on this application. 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 LIHI by e-mail at with “Holtwood Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Avenue, Office 407, Arlington, MA 02476. Comments must be received at the Institute on or before 5 pm Eastern time on April 4, 2022 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.

June 23, 2014: The Holtwood Hydroelectric Project is certified as low impact for an eight year term, effective January 20, 2014 and expiring January 20, 2022. The Holtwood Hydroelectric Project certification includes two conditions, as follows:

  • Condition modified and incorporated into 2022 recertification conditions.  Condition 1: In its annual compliance statement to LIHI, PPL-Holtwood shall provide LIHI with a copy of the Fish Passage Technical Advisory Committee Report, developed in accordance with FERC License, Article 55, which describes the status of all fish passage and protection efforts over the prior year. PPL shall summarize the latest interactions with state and federal fish management agencies concerning this report and confirm via email that the agencies agree that these monitoring efforts show sufficient progress toward the goals specified in the PA DEP Water Quality Certification, Section III, entitled Fish Passage. If established FOP goals are not being achieved, PPL shall propose solutions and implement those consistent with the PA DEP Water Quality Certification. In 2018 at the completion of Tier 1 monitoring, LIHI shall evaluate overall progress on upstream fish passage and protection for compliance with the PA DEP Water Quality certification and the FERC Operating License. LIHI certification may either be suspended or terminated if the state and federal fish management agencies do not agree that sufficient, long-term progress is being made in actual fish passage. This decision would be at the sole discretion of LIHI.
  • Condition incorporated into 2022 recertification conditions.  Condition 2:  PPL-Holtwood maintains Minimum Stream Flow (MSF) Operating Procedures and Requirements, in accordance with the PA DEP Water Quality Certification, Section IV. PPL Holtwood shall work to establish improved information sharing and understanding of on-going monitoring results for flows, water quality, and fish passage at their facility and others along the lower Susquehanna River, as requested and to the extent possible. Temporal resolution of data shall be sufficient to resolve subdaily fluctuations (e.g., hourly or instantaneous) in each Holtwood dam release and upstream reservoir elevations. This reporting work will begin with development of a draft plan for an annual “Integrated Monitoring Report (IMR) for Flows and Fish Passage” that will focus on existing environmental monitoring activities. The purposes of this new, annual IMR will be to synthesize monitoring results for the previous year at Holtwood in a format compatible with results from other FERC licensed projects on the river, promote understanding among relevant stakeholders, and provide easy access to Holtwood’s monitoring data. The IMR may be implemented either in an annual meeting (virtual or in-person) or a paper report, or both. The IMR will include evaluation of progress made relative to flow and fish goals established for the river. If agencies believe this IMR would be redundant with other reporting requirements already in place under FERC licenses, then PPL-Holtwood may explain how the IMR purposes will be achieved by means other than a new IMR and may propose dropping this LIHI condition, as long as monitoring data is being fully shared and better understanding of fish passage issues is being promoted.A draft plan for the IMR will be circulated to LIHI and to the U.S. Fish & Wildife Service, the PA Fish & Boat Commission, and the MD Department of Natural Resources within 60 days of LIHI certification for review and comment. The draft IMR plan will summarize current reporting requirements under the amended license and explain how monitoring data will be made electronically accessible to resource agency and LIHI staff, if so requested. Within 120 days of LIHI certification, the final plan for an annual IMR will be distributed to LIHI and the agencies, including response to comments received on the draft. The IMR will then be produced annually. Holtwood will report back to LIHI annually on the results of discussions and comments on the IMR in their annual compliance report for LIHI certification.

March 20, 2014: Public comment period on application closed.

January 20, 2014: PPL Holtwood, LLC submitted an application for certification of the Holtwood Project; comment period opened.

Certification Files

2022 Recertification

2014 Certification

Key Documents