Big Bend Dam

{{Short description|Dam on the Missouri River in South Dakota, US}}

{{Infobox dam

| name = Big Bend Dam

| name_official = Big Dam

| image = Image:USACE Fort Thompson Big Bend Dam.jpg

| image_size =

| image_caption = Big Bend Dam on the Missouri River, with Lake Sharpe in the background.

| image_alt =

| location_map = South Dakota

| location_map_size =

| location_map_caption = Location of Big Bend Dam in the State of South Dakota.

| coordinates = {{coord|44.049473|-99.448586|type:landmark|display=inline,title}}

| country = United States

| location = Buffalo/Lyman Counties, South Dakota.

| status = O

| construction_began = {{Start date and age|1959}}

| opening = {{Start date and age|1963}}

| demolished =

| cost = $107 million

| owner = 24px U.S. Army Corps of Engineers, Omaha District

| dam_type = Embankment, Rolled-earth shale fill & chalk fill

| dam_height = {{Convert|95|ft|m|0|abbr=on}}

| dam_height_thalweg =

| dam_height_foundation=

| dam_length = {{Convert|10570|ft|m|0|abbr=on}} (including spillway)

| dam_width_crest =

| dam_width_base = {{Convert|1200|ft|m|0|abbr=on}}

| dam_volume = {{Convert|17000000|cuyd|m3|0|abbr=on}}

| dam_elevation_crest = 1,423 feet msl

| dam_crosses = Missouri River

| spillway_count = 8 - 40-foot x 38-foot tainter gates

| spillway_type = controlled (gated)

| spillway_capacity = 270,000 cfs at 1,423 feet msl

| res_name = Lake Sharpe

| res_capacity_total = {{Convert|1798000|acre.ft|m3|0|abbr=on}}

| res_capacity_active =

| res_capacity_inactive=

| res_catchment = {{Convert|5840|sqmi|km2|0|abbr=on}}

| res_surface = {{Convert|56884|acre|abbr=on}}

| res_elevation = 1,420-1,423 feet msl

| res_max_depth = {{Convert|78|ft|m|0|abbr=on}}

| res_max_length = {{Convert|80|mi|km|0|abbr=on}}

| res_max_width =

| res_tidal_range =

| plant_operator = U.S. Army Corps of Engineers

| plant_commission = October 1964

| plant_decommission =

| plant_type =

| plant_turbines = 8 Fixed blade, 81.8 rpm

| plant_capacity = 494,320 kW

| plant_annual_gen = 969 million kilowatt hours

| website = [https://www.nwo.usace.army.mil/Missions/Dam-and-Lake-Projects/Missouri-River-Dams/Big-Bend/ U.S. Army Corps of Engineers - Big Bend Dam / Lake Sharpe]

| extra =

}}

File:Lake Sharpe Big Bend.jpg

Big Bend Dam is a major embankment rolled-earth dam on the Missouri River in Central South Dakota, United States, creating Lake Sharpe. The dam was constructed by the U.S. Army Corps of Engineers as part of the Pick-Sloan Plan for Missouri watershed development authorized by the Flood Control Act of 1944. Construction began in 1959 and the embankment was completed in July 1963. Power generation began at the facility in 1964 and the entire complex was completed in 1966 at a total cost of $107 million. The hydroelectric plant generates 493,300 kilowatts of electricity at maximum capacity, with an annual production of 969 million kilowatt hours,{{cite web|url=https://www.nwd-mr.usace.army.mil/rcc/projdata/summaryengdat.pdf|title=Summary of Engineering Data – Missouri River Main Stem System|publisher=U.S. Army Corps of Engineers|work=Missouri River Division|date=August 2010|access-date=2012-08-17|archive-date=2012-02-07|archive-url=https://web.archive.org/web/20120207121436/http://www.nwd-mr.usace.army.mil/rcc/projdata/summaryengdat.pdf|url-status=live}} and meets peak-hour demand for power within the Missouri River Basin.

Located near Fort Thompson, South Dakota, just south of the Big Bend of the Missouri River, a large meander, Big Bend Dam creates Lake Sharpe, named after South Dakota Governor Merrill Q. Sharpe. The lake extends for {{convert|80|mi}} up the course of the Missouri River passing through Pierre, the State Capitol, to Oahe Dam, another major power-generating and flood control dam. Lake Sharpe covers a total of {{convert|56884|acre}} and drains an area just under {{convert|250000|sqmi}}.

South Dakota Highway 47 crosses over the dam, connecting Lyman and Buffalo Counties. Big Bend Dam is located approximately {{convert|17|mi}} north of I-90, and approximately {{convert|60|mi}} southeast of Pierre.

The next dam upstream is Oahe Dam, near Pierre, and the next dam downstream is Fort Randall Dam, near Pickstown.