Ituango Dam

The Ituango Dam, also referred to as the Pescadero-Ituango Dam, is an embankment dam currently under construction on the Cauca River near Ituango in Antioquia Department, Colombia. The primary purpose of the project is hydroelectric power generation and its power plant will have an installed capacity of 2,456 megawatts (3,294,000 hp) when completed. Preliminary construction on the dam began in September 2011 and the power plant was expected to begin operations in late 2018, but will not after heavy rainfall and landslides in April/May 2018 blocked river's diversion tunnel, threatening a breach of the dam.[2] When completed, it will be the largest power station in Colombia.[3]

Ituango Dam
Construction site in 2014
Location of Ituango Dam in Colombia
Official namePescadero-Ituango "José Tejada Sáenz"
CountryColombia
LocationItuango
Coordinates7°07′50.04″N 75°39′48.7″W
StatusUnder construction
Construction began2011
Opening date2021 (possible[1])
Construction costUS$3.8 billion
Dam and spillways
Type of damEmbankment, earth-fill clay core
ImpoundsCauca River
Height225 m (738 ft)
Dam volume19,000,000 m3 (670,000,000 cu ft)
Spillway typeService, gate controlled
Spillway capacity22,600 m3/s (800,000 cu ft/s)
Reservoir
Total capacity2,720,000,000 m3 (2,210,000 acre⋅ft)
Active capacity980,000,000 m3 (790,000 acre⋅ft)
Surface area38 km2 (15 sq mi)
Maximum length127 km (79 mi)
Power Station
Operator(s)EPM Ituango
Hydraulic head197 m (646 ft) (nominal)
Turbines8 x 307 MW (412,000 hp) Francis type
Installed capacity2,456 MW (3,294,000 hp) (planned)
Annual generation9,200 GWh (33,000 TJ) (firm)
Website
http://www.hidroituango.com.co (Spanish)

Background

The dam's feasibility study was completed in 1983 but the project was shelved in the 1990s due to an economic crisis.[4] The final designs for the project were finished in 2008 and on 8 July 2011, the project management contract was awarded. Preliminary construction (surveying, roads, bridges, diversion tunnels) began in September 2011 and it is expected to be complete in 2013.[5] Main works will begin thereafter and the power plant is expected to being commissioning in 2018. Development of the project is being proposed by EPM Ituango, a consortium of Empresas Publicas de Medellin (EPM) and the Antioquia government. The total cost is expected to be US$2.8 billion.[6][7]

Design

The dam will be a 225-metre (738 ft) tall earth-fill embankment type with a clay core. The volume of the dam will be 19 million cubic metres (670×10^6 cu ft). Its reservoir will have a capacity of 2,720-million-cubic-metre (2,210,000 acre⋅ft) of which 980-million-cubic-metre (790,000 acre⋅ft) will be active (or "useful") capacity. The reservoir will be 127 kilometres (79 mi) long and cover an area of 38 square kilometres (15 sq mi). To maintain reservoir levels, the dam will have a spillway controlled by four radial gates with a design flow of 22,600 cubic metres per second (800,000 cu ft/s). The dam's power plant will have a nominal hydraulic head of 197 metres (646 ft) and contain eight 307 megawatts (412,000 hp) Francis turbine-generators.[8]

Diversion tunnel blockage

Three tunnels were constructed to divert the Cauca River around the construction site. Two were eventually sealed during construction, leaving a third to divert the river.[9] Between 28 April and 7 May 2018, three landslides blocked the tunnel, leading the reservoir to fill.[10] Engineers attempted to open the two closed tunnels with explosives but were unsuccessful.[11] On 10 May, when the reservoir reached the power station intake, engineers began releasing water through the unfinished power house to prevent a breach of the dam.[12] On 12 May one of the previous sealed tunnels naturally reopened, which suddenly increased downstream flows by three times the average.[13] This promoted evacuations downstream, eventually totaling around 25,000.[14]

On May 16 silt build-up in a portion of the power house, the only means to drain the reservoir, led to water escaping into a transit gallery used by construction vehicles. The water eventually poured onto the downstream face of the dam, eroding the roadway and a portion of the riprap.[15] Subsequently, EPM announced a risk of collapse existed and workers continued to fill the dam to its design height in hopes the spillway could be used to prevent an over-topping of the dam.[16] Heavy rainfall was expected in the Cauca River basin through the end of May.[17]

On May 19 the dam works reached level 405 masl; 5 m below cofferdam target the level.[18] On May 25 Dr Ordoñez issued a letter expressing his panic about the situation because "Ituango project is dead and there is no control over it, so the most natural thing is to expect it to fail; we are sure that it is easier to fail than not to fail, and we are truly in a panic".[19]

Environmental impact

Some sources argue the dam construction has severe ecological consequences, and there are displaced families, environmentalists, youth groups and concerned locals that oppose the project.[20] Other publications argue the project will benefit millions through extra revenue towards social and infrastructure programs.[21]

In February 2019 the Project came under increased pressure from local and national governmental regulatory agencies[22] because of the closure of the river flow and the environmental and economic impact downstream. Moreover, studies from the Universidad Nacional de Colombia showed that the failure of the dam is likely unless an emergency plan was adopted. The safety of the downstream communities was highlighted as critical.[23][24]

See also

References
  1. https://www.elcolombiano.com/antioquia/hidroituango-epm-investiga-socavacion-o-vacio-en-la-montana-BA10011000
  2. "Chadbourne Represented EPM Ituango in BOOMT Contract for the 2400 MW Hidroituango Project". 28 April 2011. Archived from the original on 29 July 2012. Retrieved 9 July 2011.
  3. "China, South Korea companies in race for Colombia hydropower deal". Colombia Reports. 3 February 2010. Retrieved 9 July 2011.
  4. "Colombia hydro utility to build 2,688-MW Pescadero Ituango". HydroWorld. 7 December 2011. Archived from the original on 13 March 2012. Retrieved 9 July 2011.
  5. "Construction preparation begins for 2,400-MW Ituango in Colombia". Hydro World. 22 September 2011. Archived from the original on 24 March 2016. Retrieved 29 March 2012.
  6. "Evolution of Expansion Plans" (PDF). EPM. Retrieved 9 July 2011.
  7. "Consortium wins US66 million contract for Ituango hydro project build in Colombia". HydroWorld. 8 July 2011. Archived from the original on 13 March 2012. Retrieved 9 July 2011.
  8. "Datos Técnicos" (in Spanish). Hidroeléctrica Ituango. Retrieved 9 July 2011.
  9. "Reabren 3 túneles para evacuar aguas embalsadas en Hidroituango". Caracol Radio. 8 May 2018. Retrieved 17 May 2018.
  10. "Nuevo derrumbe en proyecto Hidroituango". El Colombiano. 30 April 2018. Retrieved 17 May 2018.
  11. "Reabren 3 túneles para evacuar aguas embalsadas en Hidroituango". Caracol Radio. 8 May 2018. Retrieved 17 May 2018.
  12. "Se agrava situación en Hidroituango, deberán inundar casa de máquinas". El Tiempo. 10 May 2018. Retrieved 17 May 2018.
  13. "Así fue el destaponamiento del túnel de Hidroituango". El Colombiano. 12 May 2018. Retrieved 17 May 2018.
  14. "Hidroituango: cuatro puentes afectados deja incremento del nivel de aguas del río Cauca". W Radio. 13 May 2018. Retrieved 17 May 2018.
  15. ""Hubo una obstrucción en la casa de máquinas": EPM sobre emergencia en Hidroituango". El Espectador. 16 May 2018. Retrieved 17 May 2018.
  16. "'Existe la posibilidad de que se rompa la presa de Hidroituango': gerente de EPM". El Espectador. 17 May 2018. Retrieved 17 May 2018.
  17. "Colombia Ituango Dam Emergency 22 May 2018" (PDF). Relief Web. European Commission. Retrieved 25 May 2018.
  18. "Hidroituango dam fail emergency". Science Engineering & Sustainability. 24 March 2019. Retrieved 24 March 2019.
  19. "Hidroituango hydropower dam Colombia. Opinion from Dr Ordoñez". Science Engineering & Sustainability. 24 March 2019. Retrieved 24 March 2019.
  20. Naomi Cohen (16 January 2017). "Colombia's other war". Le Monde diplomatique. Retrieved 28 January 2017.
  21. Edgar Domínguez (13 March 2013). "Hidroituango avanza con beneficios para Antioquia". Portfolio. Retrieved 6 February 2019.
  22. Hidroituango: investigan al alcalde de Medellín y al gobernador de Antioquia, 2019-02-11, retrieved 2019-02-12
  23. "Estudio de la Universidad Nacional revela panorama preocupante del futuro de Hidroituango". Noticias Caracol (in Spanish). 2019-02-06. Retrieved 2019-02-12.
  24. Hidroituango es una amenaza para comunidades en área de influencia: científico Portilla, retrieved 2019-02-12
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.