View source for Wachusett Dam

{{Short description|Dam in Massachusetts}}
{{Use American English|date=January 2025}}
{{Use mdy dates|date=October 2021}}
{{Infobox dam
| name                 = Wachusett Dam
| image                = Wachusett-dam.jpg
| image_caption        = Wachusett Dam at [[Clinton, Massachusetts|Clinton]]
| name_official        =  Wachusett Reservoir Dam
| dam_crosses          = [[Nashua River]]
| res_name             = [[Wachusett Reservoir]]
| location             = [[Clinton, Massachusetts|Clinton]], [[Massachusetts|Massachusetts, USA]]
| operator             = [[Massachusetts Water Resources Authority|MWRA]]
| dam_length           = {{convert|965|ft|abbr=on}}
| dam_height           = {{convert|205|ft|abbr=on}}
| dam_width_base       = 
| construction_began   = {{start date and age|1897}}
| opening              = {{start date and age|1905}}
| coordinates          = {{coord|42|24|13|N|71|41|16|W|type:landmark|display=inline,title}}
| extra                = {{Infobox NRHP 
 | embed = yes
 | name = Wachusett Dam Historic District
 | nrhp_type = hd
 | nocat = yes
 | image = 
 | caption = 
 | location = [[Clinton, Massachusetts]]
 | locmapin = Massachusetts#USA
 | area =
 | architect = [[Shepley, Rutan and Coolidge]]; [[Olmsted Brothers]]
 | architecture =
 | added = January 18, 1990
 | mpsub = Water Supply System of Metropolitan Boston MPS
 | refnum = 89002269<ref name="nris">{{NRISref|2007a|dateform=mdy}}</ref>
 }}
}}

The '''Wachusett Dam''' in [[Clinton (town), Massachusetts|Clinton]], [[Massachusetts]], impounds the [[Nashua River]], creating the [[Wachusett Reservoir]]. Construction started in 1897<ref name="mwra" /> and was completed in 1905. It is part of the [[Nashua River Watershed]].

This dam is part of greater Boston's water system, maintained and controlled by the [[Massachusetts Water Resources Authority]] (MWRA). Its discharge is into the [[Nashua River]]. When it was completed in 1905, the Wachusett Reservoir was the largest public water supply reservoir in the world.<ref name="mwra">[http://www.mwra.state.ma.us/04water/html/hist4.htm History: Wachusett]</ref> At that time, the Wachusett Reservoir Dam was the largest [[Gravity dam#Gravity dams|gravity dam]] in the world as well.

==Construction==
The Metropolitan Water Board selected the south branch of the Nashua River in Clinton as the best site for Boston's new water supply over New Hampshire's [[Lake Winnipesaukee]], Maine's [[Sebago Lake]], and the [[Merrimack River]].<ref name="mwra" />

Churches, factories, homes, and schools within the valley had to be knocked down or moved. Roads and rail lines had to be relocated; a railroad tunnel and trestle had to be built in order to relocate the [[Central Massachusetts Railroad]], and over four thousand bodies had to be dug up and moved in the local Catholic cemetery.{{Citation needed|date=August 2009}} The project brought thousands of immigrants to the area for work.

The dam created the world's largest water supply reservoir at the time.<ref name="mwra" /> It is still considered the largest "hand dug" dam in the world today.{{Citation needed|date=May 2009}}

==Early problems==
A static liquefaction flow failure occurred in the upstream slope of the North Dike of Wachusett Dam near Clinton, Massachusetts on April 11, 1907 during the first reservoir filling. The fine sands of the upstream dike shell liquefied and flowed approximately 100 meters horizontally into the reservoir.

==Gallery==
<gallery>
Image:Wachusett-dam-outlet.jpg|Wachusett Dam outlet
Image:Wachusett Dam reservoir side.jpg|The reservoir side of the dam
Image:Wachusett-dam-plaque.jpg|The plaque on the dam
Image:Wachusett Dam reservoir side 2.jpg|Rough-hewn rocks lining the reservoir
Image:Wachusett reservoir.jpg|The reservoir itself
Image:Wachusett Dam, Clinton MA.jpg|The dam from downstream
</gallery>

==See also==
*[[Wachusett Aqueduct]]
*[[National Register of Historic Places listings in Worcester County, Massachusetts]]

==References==
{{Reflist}}

==External links==
{{commons category}}
* {{Structurae|id=20001117|title=Wachusett Dam}}
* [http://erp-web.er.usgs.gov/reports/annsum/vol46/ep/04hqgr0076.pdf USGS]

{{Massachusetts}}
{{National Register of Historic Places in Massachusetts}}
{{Authority control}}

[[Category:Dams in Massachusetts]]
[[Category:Historic districts in Worcester County, Massachusetts]]
[[Category:Buildings and structures in Clinton, Massachusetts]]
[[Category:Dams completed in 1905]]
[[Category:National Register of Historic Places in Worcester County, Massachusetts]]
[[Category:Historic districts on the National Register of Historic Places in Massachusetts]]
[[Category:Dams on the National Register of Historic Places in Massachusetts]]
[[Category:1905 establishments in Massachusetts]]