LIHI Certificate #116 – Holtwood Project, Pennsylvania

March 24, 2020 – COVID-19 Update: Brookfield Renewable has notified FERC of the decision to to close the Project’s campgrounds, whitewater park, and public amenities until further notice.

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 (LIHI #126), Safe Harbor, Holtwood, Muddy Run Pumped Storage Project, and Conowingo. The project first began commercial operation in 1911 and was redeveloped in 1924 to increase its capacity. The final phase of redevelopment was completed in 2014 which included raising the capacity and widening and deepening of the forebay and tailrace.

The project includes the dam, forebay, diversion wall, powerhouses, and fish passage facilities.

The dam is an overflow-type structure that consists of a 2,392-foot-long by 55-foot-high, low hazard, concrete gravity dam. The top of the dam is raised 4.75 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 backpressure on the generating units and improved fish passage. The remainder of the Susquehanna Riverbed is referred to as the spillway.

Project Name Holtwood
LIHI Certificate No. 116
LIHI Certificate Term January 20, 2014 - January 20, 2022
Owner BIF III Holtwood, LLC
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 195.5 MW (authorized) 252 MW (operational)
Average Annual Generation 1,030,503 MWh
Facility Type limited store and release
FERC No. P-1881 issued 1980, expires 2030

The Project powerhouses, including the original powerhouse constructed between 1905 and 1910, as well as the new powerhouse, are located on the east side of the river along the Lancaster County shoreline. The original powerhouse contains ten similarly sized vertical Francis turbines and two smaller vertical Francis turbine generator units, 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 operates as a limited store-and-release project that impounds Lake Aldred, a 2,600-acre reservoir. The project 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 to 98.7% of the inflow requirements of the downstream Conowingo Project. 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, Susquehanna River Basin Commission, Maryland Department of Natural Resources, U.S. Fish and Wildlife Service, 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 fall within prescribed parameters. 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.

Upstream fish passage facilities include a tailrace lift with two entrances and a spillway lift. 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 owner has agreed to successfully pass 75% of American shad that pass through downstream Conowingo facility and 50% must successfully pass within 5 days of leaving Conowingo. Downstream fish passage will be evaluated through testing. The project owner has agreed to a 95% successful 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 project transferred roughly 1,700 acres of the project land to the Lancaster County Conservancy, York County, and Conservation Society of York County. The 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.

Threatened and endangered species potentially present in the project vicinity include osprey, great blue heron, American holly, sticky goldenrod, and white doll’s daisy. The project protects osprey and great blue heron nesting sites through construction buffers and nesting season monitoring. During construction, the project avoided areas where holly trees were growing and relocated/replanted those that impeded construction. Sticky goldenrod and white doll’s daisy are found throughout the spillway and below the dam. 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 developed a Historic Properties Management Plan in coordination with FERC and the State Historic Preservation Office. The project must avoid development in the vicinity of Upper Piney Island due to the archaeological resource potential.

Recreational resources at the project include hiking trails, camping areas, fishing access points, boat ramps, and whitewater boating. Public access is provided free of charge.


Certification History

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 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 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.