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73-598: The name "Itaipu" was taken from an isle that existed near the construction site. In the Guarani language , Itaipu means "the sounding stone". The Itaipu Dam's hydroelectric power plant produced the second-most electricity of any in the world as of 2020, only surpassed by the Three Gorges Dam plant in China in electricity production. Completed in 1984, it is a binational undertaking run by Brazil and Paraguay at

146-402: A fuse plug . If present, the fuse plug is designed to wash out in case of a large flood, greater than the discharge capacity of the spillway gates. Although many months may be needed for construction crews to restore the fuse plug and channel after such an operation, the total damage and cost to repair is less than if the main water-retaining structures had been overtopped. The fuse plug concept

219-443: A baffle of concrete blocks but usually have a "flip lip" and/or dissipator basin, which creates a hydraulic jump , protecting the toe of the dam from erosion. Stepped channels and spillways have been used for over 3,000 years. Despite being superseded by more modern engineering techniques such as hydraulic jumps in the mid twentieth century, since around 1985 interest in stepped spillways and chutes has been renewed, partly due to

292-427: A clause in the treaty signed between Brazil, Paraguay and Argentina, the maximum number of generating units allowed to operate simultaneously cannot exceed 18 (see the agreement section for more information). The rated nominal power of each generating unit (turbine and generator) is 700 MW. However, because the head (difference between reservoir level and the river level at the bottom of the dam) that actually occurs

365-463: A few dams lack overflow spillways and rely entirely on bottom outlets. The two main types of spillways are controlled and uncontrolled. A controlled spillway has mechanical structures or gates to regulate the rate of flow. This design allows nearly the full height of the dam to be used for water storage year-round, and flood waters can be released as required by opening one or more gates. An uncontrolled spillway, in contrast, does not have gates; when

438-429: A language "so copious and elegant that it can compete with the most famous [of languages]". The name "Guarani" is generally used for the official language of Paraguay. However, this is part of a dialect chain , most of whose components are also often called Guarani. While Guarani, in its Classical form , was the only language spoken in the expansive missionary territories, Paraguayan Guarani has its roots outside of

511-572: A medicinal drug) comes from a homonymous Tupi–Guarani name that can be rendered as ipe-kaa-guené , meaning a creeping plant that makes one vomit. " Cougar " is borrowed from Guarani guazu ara . Spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee , typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels . Spillways ensure that water does not damage parts of

584-487: A nasal vowel, and if the consonant is voiced, it takes its nasal allophone. If a stressed syllable is nasal, the nasality spreads in both directions until it bumps up against a stressed syllable that is oral. This includes affixes , postpositions , and compounding. Voiceless consonants do not have nasal allophones, but they do not interrupt the spread of nasality. For example, However, a second stressed syllable, with an oral vowel, will not become nasalized: That is, for

657-565: A plunge pool, or two ski jumps can direct their water discharges to collide with one another. Third, a stilling basin at the terminus of a spillway serves to further dissipate energy and prevent erosion. They are usually filled with a relatively shallow depth of water and sometimes lined with concrete. A number of velocity-reducing components can be incorporated into their design to include chute blocks, baffle blocks, wing walls, surface boils, or end sills. Spillway gates may operate suddenly without warning, under remote control. Trespassers within

730-481: A predicative possessive reading. Furthermore, the conjugations vary slightly according to the stem being oral or nasal. Negation is indicated by a circumfix n(d)(V)-...-(r)i in Guarani. The preverbal portion of the circumfix is nd- for oral bases and n- for nasal bases. For 2nd person singular, an epenthetic -e- is inserted before the base, for 1st person plural inclusive, an epenthetic -a-

803-445: A result of the various hydroelectrical undertakings in the watershed that was shared by the three countries. The reservoir began its formation on October 13, 1982, when the dam works were completed and the side canal's gates were closed. Throughout this period, heavy rains and flooding accelerated the filling of the reservoir as the water rose 100 meters (330 feet) and reached the gates of the spillway on October 27. On May 5, 1984,

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876-471: A spillway only during flood periods, when the reservoir has reached its capacity and water continues entering faster than it can be released. In contrast, an intake tower is a structure used to control water release on a routine basis for purposes such as water supply and hydroelectricity generation. A spillway is located at the top of the reservoir pool. Dams may also have bottom outlets with valves or gates which may be operated to release flood flow, and

949-450: A vowel. The glottal stop , called puso in Guarani, is only written between vowels, but occurs phonetically before vowel-initial words. Because of this, some words have several glottal stops near each other that consequently undergo a number of different dissimilation techniques. For example, "I drink water" ʼaʼyʼu is pronounced hayʼu . This suggests that irregularity in verb forms derives from regular sound change processes in

1022-506: A word with a single stressed vowel, all voiced segments will be either oral or nasal, while voiceless consonants are unaffected, as in oral /ᵐbotɨ/ vs nasal /mõtɨ̃/ . Guarani is a highly agglutinative language , often classified as polysynthetic . It is a fluid-S type active language , and it has been classified as a 6th class language in Milewski's typology . It uses subject–verb–object (SVO) word order usually, but object–verb when

1095-453: A written language relatively recently. Its modern alphabet is a subset of the Latin script (with "J", "K" and "Y" but not "W"), complemented with two diacritics and six digraphs . Its orthography is largely phonemic , with letter values mostly similar to those of Spanish . The tilde is used with many letters that are considered part of the alphabet. In the case of Ñ/ñ , it differentiates

1168-414: Is a present somewhat aorist : Upe ára resẽ reho mombyry , "that day you got out and you went far". These two suffixes can be added together: ahátama , "I'm already going". This suffix can be joined with -ma , making up -páma : ñande jaikuaapáma nde remimoʼã , "now we came to know all your thought". These are unstressed suffixes: -ta, -ma, -ne, -vo, -mi ; so the stress goes upon

1241-561: Is a second official language of the Argentine province of Corrientes since 2004. Guarani is also one of the three official languages of Mercosur , alongside Spanish and Portuguese . Guarani is the most widely spoken Native American language and remains commonly used among the Paraguayan people and neighboring communities. This is unique among American languages; language shift towards European colonial languages (in this case,

1314-460: Is designed like an inverted bell , where water can enter around the entire perimeter. These uncontrolled spillways are also called morning glory (after the flower ), or glory hole spillways. In areas where the surface of the reservoir may freeze, this type of spillway is normally fitted with ice-breaking arrangements to prevent the spillway from becoming ice-bound. Some bell-mouth spillways are gate-controlled. The highest morning glory spillway in

1387-507: Is higher than the designed head (118 m or 387 ft), the power available exceeds 750 MW half of the time for each generator. Each turbine generates around 700 MW; by comparison, all the water from the Iguaçu Falls would have the capacity to feed only two generators. On November 10, 2009, transmission from the plant was completely disrupted, possibly due to a storm damaging up to three high-voltage transmission lines. Itaipu itself

1460-637: Is inserted. The postverbal portion is -ri for bases ending in -i , and -i for all others. However, in spoken Guarani, the -ri portion of the circumfix is frequently omitted for bases ending in -i . The negation can be used in all tenses, but for future or irrealis reference, the normal tense marking is replaced by moʼã , resulting in n(d)(V) -base- moʼã-i as in Ndajapomoʼãi , "I won't do it". There are also other negatives, such as: ani , ỹhỹ , nahániri , naumbre , naʼanga . The verb form without suffixes at all

1533-502: Is often translated as "ex-", "former", "abandoned", "what was once", or "one-time". These morphemes can even be combined to express the idea of something that was going to be but did not end up happening. So for example, paʼirãgue is "a person who studied to be a priest but didn't actually finish", or rather, "the ex-future priest". Some nouns use -re instead of -kue and others use -guã instead of -rã . Guarani distinguishes between inclusive and exclusive pronouns of

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1606-572: Is only 14,000 MW, behind the 22,500 MW Three Gorges Dam , the dam formerly held the record for energy production with 101.6 TWh produced in 2016. This record was beaten in 2020, when the Three Gorges Dam produced a new record 111.8 TWh after extensive monsoon rainfall that year. In the period 2012–2021, the Itaipu Dam maintained the second highest average annual hydroelectric production in the world averaging 89.22 TWh per year, second to

1679-443: Is set by dam safety guidelines, based on the size of the structure and the potential loss of human life or property downstream. The United States Army Corps of Engineers bases their requirements on the probable maximum flood (PMF) and the probable maximum precipitation (PMP). The PMP is the largest precipitation thought to be physically possible in the upstream watershed. Dams of lower hazard may be allowed to have an IDF less than

1752-604: Is used where building a spillway with the required capacity would be costly. A chute spillway is a common and basic design that transfers excess water from behind the dam down a smooth decline into the river below. These are usually designed following an ogee curve . Most often, they are lined on the bottom and sides with concrete to protect the dam and topography. They may have a controlling device and some are thinner and multiply-lined if space and funding are tight. In addition, they are not always intended to dissipate energy like stepped spillways. Chute spillways can be ingrained with

1825-587: The Jesuit Reductions . Modern scholarship has shown that Guarani was always the primary language of colonial Paraguay, both inside and outside the reductions. Following the expulsion of the Jesuits in the 18th century, the residents of the reductions gradually migrated north and west towards Asunción , a demographic shift that brought about a decidedly one-sided shift away from the Jesuit dialect that

1898-469: The Tupian language family . It is one of the official languages of Paraguay (along with Spanish ), where it is spoken by the majority of the population, and where half of the rural population are monolingual speakers of the language. Variants of the language are spoken by communities in neighboring countries including parts of northeastern Argentina , southeastern Bolivia and southwestern Brazil , and

1971-495: The nasalising tilde . The letter G̃/g̃ , which is unique to this language, was introduced into the orthography relatively recently during the mid-20th century and there is disagreement over its use. It is not a precomposed character in Unicode , which can cause typographic inconveniences – such as needing to press "delete" twice in some setups – or imperfect rendering when using computers and fonts that do not properly support

2044-553: The 100 metres (330 ft) high Power Line 4 Pylons atop the Barrage 260 metres (850 ft), dam + the foundation inside water until the river floor 247 metres (810 ft), 196 metres (643 ft) high of roof reinforcement concrete dam + Cranes atop the Barrage 225 metres (738 ft), Elevation End Main Concrete Barrage When construction of the dam began, approximately 10,000 families living beside

2117-467: The 97.22 TWh per year average of the Three Gorges Dam in that period. Guarani language Guarani ( / ˌ ɡ w ɑːr ə ˈ n iː , ˈ ɡ w ɑːr ən i / GWAR -ə- NEE , GWAR -ə-nee ), specifically the primary variety known as Paraguayan Guarani ( avañeʼẽ [ʔãʋãɲẽˈʔẽ] "the people's language"), is a South American language that belongs to the Tupi–Guarani branch of

2190-461: The Guarani spoken outside of the missions was characterized by a free, unregulated flow of Hispanicisms; frequently, Spanish words and phrases were simply incorporated into Guarani with minimal phonological adaptation. A good example of that phenomenon is found in the word "communion". The Jesuits, using their agglutinative strategy, rendered this word " Tupârahava ", a calque based on the word " Tupâ ", meaning God. In modern Paraguayan Guarani,

2263-463: The PMF. As water passes over a spillway and down the chute, potential energy converts into increasing kinetic energy . Failure to dissipate the water's energy can lead to scouring and erosion at the dam's toe (base). This can cause spillway damage and undermine the dam's stability. To put this energy in perspective, the spillways at Tarbela Dam could, at full capacity, produce 40,000 MW; about 10 times

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2336-604: The Paraná River were displaced because of construction. The world's largest waterfall by volume, the Guaíra Falls , was inundated by the newly formed Itaipu reservoir. The Brazilian government later liquidated the Guaíra Falls National Park. A few months before the reservoir was filled, 80 people died when an overcrowded bridge overlooking the falls collapsed, as tourists sought a last glimpse of

2409-574: The Spanish and IPA equivalents, although sometimes the open-mid allophones [ ɛ ] , [ ɔ ] are used more frequently. The grapheme ⟨y⟩ represents the vowel / ɨ / (as in Polish ). Considering nasality, the vowel system is perfectly symmetrical, each oral vowel having its nasal counterpart (most systems with nasals have fewer nasals than orals). Guarani displays an unusual degree of nasal harmony . A nasal syllable consists of

2482-649: The United States) won the international competition for the realization of the viability studies and for the elaboration of the construction project. Design studies began in February 1971. On April 26, 1973, Brazil and Paraguay signed the Itaipu Treaty, the legal instrument for the hydroelectric exploitation of the Paraná River by the two countries. On May 17, 1974, the Itaipu Binacional entity

2555-510: The blind. Guarani syllables consist of a consonant plus a vowel or a vowel alone; syllables ending in a consonant or two or more consonants together do not occur. This is represented as (C)V . In the below table, the IPA value is shown. The orthography is shown in angle brackets below, if different. The voiced consonants have oral allophones (left) before oral vowels, and nasal allophones (right) before nasal vowels . The oral allophones of

2628-597: The border between the two countries, 15 km (9.3 mi) north of the Friendship Bridge . The project ranges from Foz do Iguaçu , in Brazil, and Ciudad del Este in Paraguay, in the south to Guaíra and Salto del Guairá in the north. The installed generation capacity of the plant is 14 GW, with 20 generating units providing 700 MW each with a hydraulic design head of 118 metres (387 ft). In 2016,

2701-407: The capacity of its power plant. The energy can be dissipated by addressing one or more parts of a spillway's design. First, on the spillway surface itself by a series of steps along the spillway (see stepped spillway ). Second, at the base of a spillway, a flip bucket can create a hydraulic jump and deflect water upwards. A ski jump can direct water horizontally and eventually down into

2774-430: The complex layout feature of glyph composition. Only stressed nasal vowels are written as nasal. If an oral vowel is stressed, and it is not the final syllable, it is marked with an acute accent: á, é, í, ó, ú, ý . That is, stress falls on the vowel marked as nasalized, if any, else on the accent-marked syllable, and if neither appears, then on the final syllable. Guarani Braille is the braille alphabet used for

2847-467: The dam was first contested by Argentina , but the negotiations and resolution of the dispute ended up setting the basis for Argentine–Brazilian integration later on. An important diplomatic settlement was reached with the signing of the Acordo Tripartite by Brazil, Paraguay and Argentina, on October 19, 1979. This agreement established the allowed river levels and how much they could change as

2920-414: The difference in height between the intake and the outlet to create the pressure difference required to remove excess water. Siphons require priming to remove air in the bend for them to function, and most siphon spillways are designed to use water to automatically prime the siphon. One such design is the volute siphon, which employs volutes or fins on a funnel to form water into a vortex that draws air out of

2993-481: The falls. The Guaíra Falls was an effective barrier that separated freshwater species in the upper Paraná basin (with its many endemics ) from species found below it, and the two are recognized as different ecoregions . After the falls disappeared, many species formerly restricted to one of these areas have been able to invade the other, causing problems typically associated with introduced species . For example, more than 30 fish species that formerly were restricted to

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3066-644: The first generation unit started running in Itaipu. The first 18 units were installed at the rate of two to three a year; the last two of these started running in the year 1991. The last two of the 20 electric generation units started operations in September 2006 and in March 2007, thus raising the installed capacity to 14 GW and completing the power plant. This increase in capacity allows 18 generation units to run permanently while two are shut down for maintenance. Due to

3139-410: The first person plural. Reflexive pronoun: je : ahecha ("I look"), ajehecha ("I look at myself") Guarani stems can be divided into a number of conjugation classes, which are called areal (with the subclass aireal ) and chendal . The names for these classes stem from the names of the prefixes for 1st and 2nd person singular. The areal conjugation is used to convey that

3212-423: The flood is sometimes expressed as a return period . A 100-year recurrence interval is the flood magnitude expected to be exceeded on the average of once in 100 years. This parameter may be expressed as an exceedance frequency with a 1% chance of being exceeded in any given year. The volume of water expected during the design flood is obtained by hydrologic calculations of the upstream watershed. The return period

3285-424: The history of Guarani. There also seems to be some degree of variation between how much the glottal stop is dropped (for example aruʼuka > aruuka > aruka for "I bring"). It is possible that word-internal glottal stops may have been retained from fossilized compounds where the second component was a vowel-initial (and therefore glottal stop–initial) root. /a/, /e/, /i/, /o/, /u/ correspond more or less to

3358-629: The interior of Rio Grande do Sul, Santa Catarina, Mato Grosso do Sul, Mato Grosso, the interior of Bahia and parts of Pernambuco, energy officials said. By 00:30 power had been restored to most areas. In 1994, the American Society of Civil Engineers elected the Itaipu Dam as one of the seven modern Wonders of the World . In 1995, the American magazine Popular Mechanics published the results. 325 metres (1,066 ft), entire dam including

3431-489: The last syllable of the verb or the last stressed syllable. The close and prolonged contact Spanish and Guarani have experienced has resulted in many Guarani words of Spanish origin. Many of these loans were for things or concepts unknown to the New World prior to Spanish colonization . Examples are seen below: English has adopted a small number of words from Guarani (or perhaps the related Tupi ) via Portuguese, mostly

3504-615: The majority of the energy to the São Paulo / Rio de Janeiro region where the terminal equipment converts the power to 60 Hz. The concept behind the Itaipu Power Plant was the result of serious negotiations between the two countries during the 1960s. The "Ata do Iguaçu" (Iguaçu Act) was signed on July 22, 1966, by the Brazilian and Paraguayan Ministers of Foreign Affairs, Juracy Magalhães and Raúl Sapena Pastor . This

3577-465: The missionaries had curated in the southern and eastern territories of the colony. By and large, the Guarani of the Jesuits shied away from direct phonological loans from Spanish. Instead, the missionaries relied on the agglutinative nature of the language to formulate new precise translations or calque terms from Guarani morphemes. This process often led the Jesuits to employ complicated, highly synthetic terms to convey European concepts. By contrast,

3650-519: The names of animals or plants. " Jaguar " comes from jaguarete and " piraña " comes from pira aña ("tooth fish" Tupi: pirá 'fish', aña 'tooth'). Other words are: " agouti " from akuti , " tapir " from tapira , " açaí " from ĩwasaʼi ("[fruit that] cries or expels water"), " warrah " from aguará meaning "fox", and " margay " from mbarakaja'y meaning "small cat". Jacaranda , guarana and mandioca are words of Guarani or Tupi–Guarani origin. Ipecacuanha (the name of

3723-460: The nasal allophone is always [ ɲ ] . The dorsal fricative is in free variation between [ x ] and [ h ] . ⟨g⟩ , ⟨gu⟩ are approximants, not fricatives, but are sometimes transcribed [ ɣ ] , [ ɣʷ ] , as is conventional for Spanish. ⟨gu⟩ is also transcribed [ɰʷ] , which is essentially identical to [ w ] . All syllables are open, viz. CV or V, ending in

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3796-565: The other official language of Spanish ) has otherwise been a nearly universal phenomenon in the Western Hemisphere , but Paraguayans have maintained their traditional language while also adopting Spanish. Jesuit priest Antonio Ruiz de Montoya , who in 1639 published the first written grammar of Guarani in a book called Tesoro de la lengua guaraní (Treasure/ Thesaurus of the Guarani Language) , described it as

3869-517: The palatal nasal from the alveolar nasal (as in Spanish), whereas it marks stressed nasalisation when used over a vowel (as in Portuguese ): ã, ẽ, ĩ, õ, ũ, ỹ . (Nasal vowels have been written with several other diacritics: ä, ā, â, ã .) The tilde also marks nasality in the case of G̃/g̃ , used to represent the nasalized velar approximant by combining the velar approximant G with

3942-665: The participant is actively involved , whereas the chendal conjugation is used to convey that the participant is the undergoer . However, the areal conjugation is also used if an intransitive verb expresses an event as opposed to a state , for example manó 'die', and even with a verb such as ké 'sleep'. In addition, all borrowed Spanish verbs are adopted as areal as opposed to borrowed adjectives, which take chendal . Intransitive verbs can take either conjugation, transitive verbs normally take areal , but can take chendal for habitual readings. Nouns can also be conjugated, but only as chendal . This conveys

4015-429: The plant employed 3038 workers. Of the twenty generator units currently installed, ten generate at 50  Hz for Paraguay and ten generate at 60 Hz for Brazil. Since the output capacity of the Paraguayan generators far exceeds the load in Paraguay, most of their production is exported directly to the Brazilian side, from where two 600 kV HVDC lines, each approximately 800 kilometres (500 mi) long, carry

4088-571: The region below the falls have been able to invade the region above. The American composer Philip Glass has written a symphonic cantata named Itaipu , in honour of the structure. The Santa Maria Ecological Corridor now connects the Iguaçu National Park with the protected margins of Lake Itaipu , and via these margins with the Ilha Grande National Park . Although its designed peak generating capacity

4161-411: The reservoir is controlled by the mechanical gates. In this case, the dam is not designed to function with water flowing over the top if it, either due to the materials used for its construction or conditions directly downstream. If inflow to the reservoir exceeds the gate's capacity, an artificial channel called an auxiliary or emergency spillway will convey water. Often, that is intentionally blocked by

4234-459: The river downstream. One parameter of spillway design is the largest flood it is designed to handle. The structures must safely withstand the appropriate spillway design flood (SDF), sometimes called the inflow design flood (IDF). The magnitude of the SDF may be set by dam safety guidelines, based on the size of the structure and the potential loss of human life or property downstream. The magnitude of

4307-595: The same word is rendered " komuño ". Following the out-migration from the reductions, these two distinct dialects of Guarani came into extensive contact for the first time. The vast majority of speakers abandoned the less colloquial, highly regulated Jesuit variant in favor of the variety that evolved from actual use by speakers in Paraguay. This contemporary form of spoken Guarani is known as Jopará , meaning "mixture" in Guarani. Widely spoken, Paraguayan Guarani has nevertheless been repressed by Paraguayan governments throughout most of its history since independence. It

4380-414: The spillway are at high risk of drowning. Spillways are usually fenced and equipped with locked gates to prevent casual trespassing within the structure. Warning signs, sirens, and other measures may be in place to warn users of the downstream area of sudden release of water. Operating protocols may require "cracking" a gate to release a small amount of water to warn persons downstream. The sudden closure of

4453-539: The structure not designed to convey water. Spillways can include floodgates and fuse plugs to regulate water flow and reservoir level. Such features enable a spillway to regulate downstream flow—by releasing water in a controlled manner before the reservoir is full, operators can prevent an unacceptably large release later. Other uses of the term "spillway" include bypasses of dams and outlets of channels used during high water, and outlet channels carved through natural dams such as moraines . Water normally flows over

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4526-605: The subject is not specified. The language lacks gender and has no native definite article but, due to influence from Spanish, la is used as a definite article for singular reference and lo for plural reference. These are not found in Classical Guarani ( Guaraniete ). Guarani exhibits nominal tense: past, expressed with -kue , and future, expressed with -rã . For example, tetã ruvichakue translates to "ex-president" while tetã ruvicharã translates to "president-elect." The past morpheme -kue

4599-424: The system. The priming happens automatically when the water level rises above the inlets. The ogee crest over-tops a dam, a side channel wraps around the topography of a dam, and a labyrinth uses a zig-zag design to increase the sill length for a thinner design and increased discharge. A drop inlet resembles an intake for a hydroelectric power plant, and transfers water from behind the dam directly through tunnels to

4672-409: The terms of the treaty with Brazil, which long remained hostile to any renegotiation. In 2009, Brazil agreed to a fairer payment of electricity to Paraguay and also allowed Paraguay to sell excess power directly to Brazilian companies instead of solely through the Brazilian electricity monopoly. In 1970, the consortium formed by the companies ELC Electroconsult S.p.A. (from Italy) and IECO (from

4745-474: The use of new construction materials (e.g. roller-compacted concrete , gabions ) and design techniques (e.g. embankment overtopping protection). The steps produce considerable energy dissipation along the chute and reduce the size of the required downstream energy dissipation basin. Research is still active on the topic, with newer developments on embankment dam overflow protection systems, converging spillways and small weir design. A bell-mouth spillway

4818-405: The voiced stops are prenasalized . There is also a sequence /ⁿt/ (written ⟨nt⟩ ). A trill /r/ (written ⟨rr⟩ ), and the consonants /l/ , /f/ , and /j/ (written ⟨ll⟩ ) are not native to Guarani, but come from Spanish. Oral /ᵈj/ is often pronounced [ dʒ ] , [ ɟ ] , [ ʒ ] , [ j ] , depending on the dialect, but

4891-474: The water rises above the lip or crest of the spillway, it begins to be released from the reservoir. The rate of discharge is controlled only by the height of water above the reservoir's spillway. The fraction of storage volume in the reservoir above the spillway crest can only be used for the temporary storage of floodwater; it cannot be used as water supply storage because it sits higher than the dam can retain it. In an intermediate type, normal level regulation of

4964-695: The world is at Hungry Horse Dam in Montana, U.S., and is controlled by a 64-by-12-foot (19.5 by 3.7 m) ring gate. The bell-mouth spillway in Covão dos Conchos reservoir in Portugal is constructed to look like a natural formation. The largest bell-mouth spillway is in Geehi Dam , in New South Wales, Australia, measuring 105 ft (32 m) in diameter at the lake's surface. A siphon uses

5037-596: Was a joint declaration of the mutual interest in studying the exploitation of the hydro resources that the two countries shared in the section of the Paraná River starting from, and including, the Salto de Sete Quedas , to the Iguaçu River watershed. The treaty that gave origin to the power plant was signed in 1973. The terms of the treaty, which expired in 2023, have been the subject of widespread discontent in Paraguay. The government of President Lugo vowed to renegotiate

5110-519: Was created to administer the plant's construction. The construction began in January of the following year. Brazil's (and Latin America's) first electric car was introduced in late 1974; it received the name Itaipu in honor of the project. On October 14, 1978, the Paraná River had its route changed, which allowed a section of the riverbed to dry so the dam could be built there. The construction of

5183-544: Was established in the new constitution as a language equal to Spanish. Jopará, the mixture of Spanish and Guarani, is spoken by an estimated 90% of the population of Paraguay. Code-switching between the two languages takes place on a spectrum in which more Spanish is used for official and business-related matters, and more Guarani is used in art and in everyday life. Guarani is also an official language of Bolivia and of Corrientes Province in Argentina. Guarani became

5256-465: Was not damaged. This caused massive power outages in Brazil and Paraguay, blacking out the entire country of Paraguay for 15 minutes, and plunging Rio de Janeiro and São Paulo into darkness for more than 2 hours. 50 million people were reportedly affected. The blackout occurred at 22:13 local time. It affected the southeast of Brazil most severely, leaving São Paulo, Rio de Janeiro and Espírito Santo completely without electricity. Blackouts also swept through

5329-423: Was prohibited in state schools for over 100 years. However, populists often used pride in the language to excite nationalistic fervor and promote a narrative of social unity. During the autocratic regime of Alfredo Stroessner , his Colorado Party used the language to appeal to common Paraguayans although Stroessner himself never gave an address in Guarani. Upon the advent of Paraguayan democracy in 1992, Guarani

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