Holtwood Dam
Encyclopedia
Holtwood Dam is the oldest of three major dam
s built across the lower Susquehanna River
, and the middle location of the three. It was constructed as the McCalls Ferry Dam between 1905 and 1910 by the Pennsylvania Water & Power Company. The dam was renamed Holtwood in honor of two company executives. PW&P merged with the current owner of the dam, Pennsylvania Power & Light
(PPL), in 1955.
driven generators
. The dam consists of a main concrete dam, which is mostly one continuous spillway
, with a power house at the eastern end. The water level is raised by wooden flash boards and inflatable dam sections.
The western end of the dam has the original, and ineffective, fish ladder
. In the mid 1990s, construction started on a fish lift. The fish lift and dam were damaged by heavy rain and rapid snowmelt from the severe 1996 flood in January of that year. The new fish lift was completed in time for the 1997 season and began lifting american shad
and other migratory fish species.
The Kingsbury thrust bearing of Holtwood's Generator No. 5 is designated an International Historic Mechanical
Engineering Landmark. Previously used roller bearings would last about 2 months under the generator's 220 ton load, but the Kingsbury bearing has been in use since 1912.
The impounded water, Lake Aldred, was originally dredged for anthracite coal
silt, or fines, washed downstream from the coal mining regions of Pennsylvania
. This coal was used in the adjacent Holtwood Steam Generator station. When Safe Harbor Dam
was built upstream, its impoundment was then "mined" for coal as well. More efficient primary mining upstream reduced the availability of fines, and 1972 environmental laws made the dredging impractical, so coal was brought in by train.
PPL received the approval to add the second powerhouse in November 2009 from the Federal Energy Regulatory Commission
. Expansion of the plant started in 2010. Preliminary construction began in January 2010, with full construction beginning in April 2010. The project is scheduled for a spring 2013 completion date. The second powerhouse is expected to add 125 MW of additional capacity.
One worker has already been killed during construction of the second powerhouse. Bruce Hardy, 59, of Bainbridge, Lancaster County, died after being crushed between a wall an excavator bucket.
The area below the dam is popular with whitewater kayakers
, with eleven named hydraulic features. PPL plans to expand the dam are being challenged by this group.
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s built across the lower Susquehanna River
Susquehanna River
The Susquehanna River is a river located in the northeastern United States. At long, it is the longest river on the American east coast that drains into the Atlantic Ocean, and with its watershed it is the 16th largest river in the United States, and the longest river in the continental United...
, and the middle location of the three. It was constructed as the McCalls Ferry Dam between 1905 and 1910 by the Pennsylvania Water & Power Company. The dam was renamed Holtwood in honor of two company executives. PW&P merged with the current owner of the dam, Pennsylvania Power & Light
PPL (utility)
PPL, formerly known as PP&L or Pennsylvania Power and Light, is an energy company headquartered in Allentown, Pennsylvania, USA. It currently controls about 19,000 megawatts of electrical generating capacity in the United States, primarily in Pennsylvania and Montana, and delivers electricity to...
(PPL), in 1955.
Holtwood hydroelectric plant
The Holtwood Hydroelectric Plant produces 109 Megawatts of power, using 10 turbineWater turbine
A water turbine is a rotary engine that takes energy from moving water.Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy...
driven generators
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
. The dam consists of a main concrete dam, which is mostly one continuous spillway
Spillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
, with a power house at the eastern end. The water level is raised by wooden flash boards and inflatable dam sections.
The western end of the dam has the original, and ineffective, fish ladder
Fish ladder
A fish ladder, also known as a fishway, fish pass or fish steps, is a structure on or around artificial barriers to facilitate diadromous fishes' natural migration. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps into the waters on...
. In the mid 1990s, construction started on a fish lift. The fish lift and dam were damaged by heavy rain and rapid snowmelt from the severe 1996 flood in January of that year. The new fish lift was completed in time for the 1997 season and began lifting american shad
American shad
-Introduction:The American shad or Atlantic shad, Alosa sapidissima, is a species of anadromous fish in family Clupeidae of order Clupeiformes. It is not closely related to the other North American shads...
and other migratory fish species.
The Kingsbury thrust bearing of Holtwood's Generator No. 5 is designated an International Historic Mechanical
Engineering Landmark. Previously used roller bearings would last about 2 months under the generator's 220 ton load, but the Kingsbury bearing has been in use since 1912.
The impounded water, Lake Aldred, was originally dredged for anthracite coal
Anthracite coal
Anthracite is a hard, compact variety of mineral coal that has a high luster...
silt, or fines, washed downstream from the coal mining regions of Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
. This coal was used in the adjacent Holtwood Steam Generator station. When Safe Harbor Dam
Safe Harbor Dam
The Safe Harbor Dam is a concrete gravity dam on the lower Susquehanna River with an associated hydroelectric power station. It is the most northerly and last of three Great Depression-era public electrification projects' hydroelectric dams and was constructed between 1 April 1930 and 7 December...
was built upstream, its impoundment was then "mined" for coal as well. More efficient primary mining upstream reduced the availability of fines, and 1972 environmental laws made the dredging impractical, so coal was brought in by train.
Expansion project
In 2008, PPL announced plans to expand the plant with a second powerhouse.PPL received the approval to add the second powerhouse in November 2009 from the Federal Energy Regulatory Commission
Federal Energy Regulatory Commission
The Federal Energy Regulatory Commission is the United States federal agency with jurisdiction over interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas pricing, and oil pipeline rates...
. Expansion of the plant started in 2010. Preliminary construction began in January 2010, with full construction beginning in April 2010. The project is scheduled for a spring 2013 completion date. The second powerhouse is expected to add 125 MW of additional capacity.
One worker has already been killed during construction of the second powerhouse. Bruce Hardy, 59, of Bainbridge, Lancaster County, died after being crushed between a wall an excavator bucket.
The area below the dam is popular with whitewater kayakers
Whitewater kayaking
Whitewater kayaking is the sport of paddling a kayak on a moving body of water, typically a whitewater river. Whitewater kayaking can range from simple, carefree gently moving water, to demanding, dangerous whitewater. River rapids are graded like ski runs according to the difficulty, danger or...
, with eleven named hydraulic features. PPL plans to expand the dam are being challenged by this group.