Holtwood Dam

Infobox_Dam
dam_name= Holtwood Dam


caption=
official_name= Holtwood Hydroelectric Plant
crosses= Susquehanna River
reservoir= Lake Aldred
locale= South central Pennsylvania, USA
maint= PPL Corporation
length= 2,392 feet (729 m)
height= 55 feet (17 m)
width=
began=1905
open= 1910
closed=
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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. [cite web |url= http://www.rootsweb.com/~pacahs/marimg.htm |title= The Conestoga Area Historical Society - Martic Township |accessdate=2006-07-22] 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. [cite web |url= http://www.pplweb.com/newsroom/newsroom+quick+links/archived+news/2005/May/Holtwood+Dam+Repair+Work.htm |title= Lake Aldred Water Level to Drop for Holtwood Dam Maintenance |accessdate= 2006-07-22]

The western end of the dam has the original, and ineffective, fish ladder. In the mid 1990s, construction started on a fish lift. In January, 1996 the fish lift and dam were damaged by the severe 1996 flood. The new fish lift was completed in time for the 1997 season [cite web |url= http://www.shwpc.com/fishlift.html | title= How Fish Lifts Work |publisher= Safe Harbor Water Power Corporation |accessdate= 2006-07-22] 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 has been in use since 1912.cite web |url=http://files.asme.org/ASMEORG/Communities/History/Landmarks/5583.pdf |title= The Kingsbury Bearing at Holtwood |publisher= The American Society of Mechanical Engineers |format= PDF |accessdate=2006-07-22]

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.

Proposed project

PPL has announced plans to install a second powerhouse with water-driven turbines at the dam. If approved by the Federal Energy Regulatory Commission and the Pennsylvania Department of Environmental Protection, the project could be completed by 2011. The addition would increase the electric generating capacity of the dam by about 80 MW. [cite web|url=http://www.ferc.gov/industries/hydropower/enviro/eis/2008/07-18-08.asp|title=Draft FERC Environmental Impact Statement for License Amendment for the Holtwood Hydroelectric Project|date=July 2008|accessdate=2008-08-06]

The area below the dam is popular with whitewater kayakers, with eleven named hydraulic features. [cite web |last= Laucks |first= Jeremy |url=http://www.chasingrain.com/surfguide/Holtwoodguide.pdf |format= PDF |title= Susquehanna Surf Guide |accessdate=2006-07-22] PPL plans to expand the dam are being challenged by this group. [cite web |last= Colburn |first= Kevin|url= http://www.americanwhitewater.org/content/Article/display/articleid/1700/display/full |title= New Project Threatens Holtwood Playspots (PA) |accessdate= 2006-07-22]

See also

*List of dams and reservoirs of the Susquehanna River

External links

* [http://www.pplweb.com/holtwood/ PPL Holtwood Environmental Preserve]
* [http://www.pbase.com/tornadoalleyhoops/image/36631350 Holtwood Dam Photo]
* [http://www.treklens.com/gallery/North_America/United_States/photo31900.htm Holtwood Hydroelectric Plant Photo]

References