|Official name||Holtwood Hydroelectric Plant|
|Location||Martic Township, Lancaster County / Lower Chanceford Township, York County, Pennsylvania, USA|
|Dam and spillways|
|Height||55 feet (17 m)|
|Length||2,392 feet (729 m)|
Holtwood Dam (also Holtwood Hydroelectric Dam, Holtwood Hydroelectric Plant, McCalls Ferry Dam) is the oldest of three major dams 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.
Holtwood hydroelectric plant
The Holtwood Hydroelectric Plant produces 109 Megawatts of power, using 10 turbine 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.
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. 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 and an excavator bucket.
- "The Conestoga Area Historical Society - Martic Township". Retrieved 2006-07-22.
- "Lake Aldred Water Level to Drop for Holtwood Dam Maintenance". Retrieved 2006-07-22.
- "How Fish Lifts Work". Safe Harbor Water Power Corporation. Retrieved 2006-07-22.
- "The Kingsbury Bearing at Holtwood" (PDF). The American Society of Mechanical Engineers. Retrieved 2006-07-22.
- "Draft FERC Environmental Impact Statement for License Amendment for the Holtwood Hydroelectric Project". July 2008. Retrieved 2008-08-06.
- "Construction begins on Holtwood hydropower project expansion". 2010-04-30. Retrieved 2011-05-09.
- "Police Identify Worker Killed At Holtwood Dam". 2010-12-16. Retrieved 2011-05-09.
- Laucks, Jeremy. "Susquehanna Surf Guide" (PDF). Retrieved 2006-07-22.
- Colburn, Kevin. "New Project Threatens Holtwood Playspots (PA)". Retrieved 2006-07-22.