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110-592: New Don Pedro Dam , often known simply as Don Pedro Dam , is an earthen embankment dam across the Tuolumne River , about 2 miles (3.2 km) northeast of La Grange , in Tuolumne County, California . The dam was completed in 1971, after four years of construction, to replace the 1924 concrete-arch Don Pedro Dam . The dam serves mainly for irrigation water storage, flood control and hydroelectricity production, and impounds Don Pedro Reservoir in

220-434: A ghost town of abandoned ships and businesses, but then boomed as merchants and new people arrived. The population of San Francisco increased quickly from about 1,000 in 1848 to 25,000 full-time residents by 1850. Miners lived in tents, wood shanties, or deck cabins removed from abandoned ships. There was no churches or religious services in the rapidly growing city, which prompted missionaries like William Taylor to meet

330-584: A state constitution was written . The new constitution was adopted by referendum vote; the future state's interim first governor and legislature were chosen. In September 1850, California became a state . At the beginning of the gold rush, there was no law regarding property rights in the goldfields and a system of "staking claims" was developed. Prospectors retrieved the gold from streams and riverbeds using simple techniques, such as panning . Although mining caused environmental harm, more sophisticated methods of gold recovery were developed and later adopted around

440-471: A businessman who went on to great success was Levi Strauss , who first began selling denim overalls in San Francisco in 1853. Other businessmen reaped great rewards in retail, shipping, entertainment, lodging, or transportation. Boardinghouses, food preparation, sewing, and laundry were highly profitable businesses often run by women (married, single, or widowed) who realized men would pay well for

550-417: A canyon adjacent to Lake Don Pedro, creating a reservoir with a capacity of 25,000 to 42,000 acre-feet (0.031 to 0.052 km). Water would be pumped into this new reservoir using power generated at New Don Pedro Dam during periods of low electricity demand, while during high demand water would be released through a penstock to an 880 MW generating facility. As of September 2011, poor economic conditions had put

660-435: A capacity of 172,000 cubic feet per second (4,900 m/s), and finally the emergency spillway, a 995-foot (303 m) long concrete overflow structure, can discharge more than 300,000 cubic feet per second (8,500 m/s). The hydroelectric plant at the base of the dam has four generators capable of producing 203 MW combined. The TID's share is 139 MW or 68.47%, while MID receives 64 MW or 31.53%. Three generators, each with

770-479: A capacity of 2,030,000 acre-feet (2.50 km), of which 340,000 acre-feet (0.42 km) is reserved for flood control and 1,381,000 acre-feet (1.703 km) is available for irrigation, municipal water supply, and hydroelectric generation. The flood control reservation is one of the smallest among major California reservoirs because it allows for more water to be stored for power generation, but this has often resulted in inadequate flood protection such as in 1997 when

880-405: A capacity of 55 MW, were included in the original design of the dam while an additional 38 MW generator was incorporated in 1989. The plant generates an average of 618.4 million kilowatt hours (KWh) of electricity each year, equal to an average output of 70.6 MW. The cities of Modesto and Turlock receive a large share of their power supplies from New Don Pedro Dam. Don Pedro Reservoir has

990-418: A dam and the filling of the reservoir behind it places a new weight on the floor and sides of a valley. The stress of the water increases linearly with its depth. Water also pushes against the upstream face of the dam, a nonrigid structure that under stress behaves semiplastically, and causes greater need for adjustment (flexibility) near the base of the dam than at shallower water levels. Thus the stress level of

1100-483: A few years, there was an important but lesser-known surge of prospectors into far Northern California, specifically into present-day Siskiyou , Shasta and Trinity Counties . Discovery of gold nuggets at the site of present-day Yreka in 1851 brought thousands of gold-seekers up the Siskiyou Trail and throughout California's northern counties. Settlements of the gold rush era, such as Portuguese Flat on

1210-578: A few, though many who participated in the California gold rush earned little more than they had started with. Gold was discovered in California as early as March 9, 1842, at Rancho San Francisco , in the mountains north of present-day Los Angeles. Californian native Francisco Lopez was searching for stray horses and stopped on the bank of a small creek (in today's Placerita Canyon ), about 3 miles (4.8 km) east of present-day Newhall , and about 35 miles (56 km) northwest of Los Angeles. While

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1320-533: A landing strip, and hiking trails, including on 14 of the 33 islands in the lake. Don Pedro has become a popular summer destination in Central California, attracting 360,000–400,000 visitors each year. In 1923, the same year that Old Don Pedro was completed, the City of San Francisco finished construction of O'Shaughnessy Dam , which forms a reservoir in the upper Tuolumne River's Hetch Hetchy Valley and

1430-476: A large sea; underwater volcanoes deposited lava and minerals (including gold) onto the sea floor. By tectonic forces these minerals and rocks came to the surface of the Sierra Nevada, and eroded . Water carried the exposed gold downstream and deposited it in quiet gravel beds along the sides of old rivers and streams. The forty-niners first focused their efforts on these deposits of gold. Because

1540-488: A method that involved digging a shaft 6 to 13 meters (20 to 43 ft) deep into placer deposits along a stream. Tunnels were then dug in all directions to reach the richest veins of pay dirt . In the most complex placer mining, groups of prospectors would divert the water from an entire river into a sluice alongside the river and then dig for gold in the newly exposed river bottom. Modern estimates are that as much as 12 million ounces (370  t ) of gold were removed in

1650-431: A month behind schedule. Cleanup proceeded at a rapid pace and placing of impervious material for the dam's core commenced on February 27. For the next fifteen months, a fleet of massive 125-ton (113 t) dump trucks delivered an almost constant stream of dirt and rock to the site, and the dam wall rose at an average rate of one and a half feet (0.46 m) per day. The workforce peaked at 500 men in mid-1969 and on December 10,

1760-517: A possession of the United States, but it was not a formal " territory " and did not become a state until September 9, 1850. California existed in the unusual condition of a region under military control. There was no civil legislature, executive or judicial body for the entire region. Local residents operated under a confusing and changing mixture of Mexican rules, American principles, and personal dictates. Lax enforcement of federal laws, such as

1870-410: A previously claimed site. Disputes were often handled personally and violently, and were sometimes addressed by groups of prospectors acting as arbitrators . This often led to heightened ethnic tensions. In some areas the influx of many prospectors could lead to a reduction of the existing claim size by simple pressure. Approximately four hundred million years ago, California lay at the bottom of

1980-415: A prospector, but that claim was valid only as long as it was being actively worked. Miners worked at a claim only long enough to determine its potential. If a claim was deemed as low-value—as most were—miners would abandon the site in search of a better one. In the case where a claim was abandoned or not worked upon, other miners would "claim-jump" the land. "Claim-jumping" meant that a miner began work on

2090-413: A service done by a woman. Brothels also brought in large profits, especially when combined with saloons and gaming houses. By 1855, the economic climate had changed dramatically. Gold could be retrieved profitably from the goldfields only by medium to large groups of workers, either in partnerships or as employees. By the mid-1850s, it was the owners of these gold-mining companies who made the money. Also,

2200-434: A simple embankment of well-compacted earth. A homogeneous rolled-earth dam is entirely constructed of one type of material but may contain a drain layer to collect seep water. A zoned-earth dam has distinct parts or zones of dissimilar material, typically a shell of locally plentiful material with a watertight clay core. Modern zoned-earth embankments employ filter and drain zones to collect and remove seep water and preserve

2310-510: A small number (probably fewer than 500) traveled overland from the United States that year. Some of these "forty-eighters", as the earliest gold-seekers were sometimes called, were able to collect large amounts of easily accessible gold—in some cases, thousands of dollars worth each day. Even ordinary prospectors averaged daily gold finds worth 10 to 15 times the daily wage of a laborer on the East Coast. A person could work for six months in

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2420-404: A small sustained overtopping flow can remove thousands of tons of overburden soil from the mass of the dam within hours. The removal of this mass unbalances the forces that stabilize the dam against its reservoir as the mass of water still impounded behind the dam presses against the lightened mass of the embankment, made lighter by surface erosion. As the mass of the dam erodes, the force exerted by

2530-686: A thick suspension of earth, rocks and water. Therefore, safety requirements for the spillway are high, and require it to be capable of containing a maximum flood stage. It is common for its specifications to be written such that it can contain at least a one-hundred-year flood. A number of embankment dam overtopping protection systems were developed in the early 21st century. These techniques include concrete overtopping protection systems, timber cribs , sheet-piles , riprap and gabions , Reinforced Earth , minimum energy loss weirs , embankment overflow stepped spillways , and precast concrete block protection systems. All dams are prone to seepage underneath

2640-546: A vial of gold, shouting "Gold! Gold! Gold from the American River!" On August 19, 1848, the New York Herald was the first major newspaper on the East Coast to report the discovery of gold. On December 5, 1848, US President James K. Polk confirmed the discovery of gold in an address to Congress . As a result, individuals seeking to benefit from the gold rush—later called the "forty-niners"—began moving to

2750-459: A year's supply of water for valley farmers, with no guarantee that a multiyear drought could be weathered. An enlarged Don Pedro would provide a "bank" of water storage for prolonged droughts, capture more spring runoff, and provide increased flood control. Another proponent of a high dam was the city of San Francisco , which also sought a share of the Tuolumne's water and decided to cooperate with

2860-474: Is 40 feet (12 m) wide at the crest and over 2,800 feet (850 m) wide at the base. High water releases are controlled by four sets of gates. A set of internal gates in the diversion tunnel can release up to 7,370 cubic feet per second (209 m/s), while a hollow jet valve at the base of the dam can discharge 3,100 cubic feet per second (88 m/s). The service spillway, controlled by three 45-by-30-foot (13.7 m × 9.1 m) radial gates , has

2970-630: Is a large dam on the Indus River in Pakistan , about 50 km (31 mi) northwest of Islamabad . Its height of 485 ft (148 m) above the river bed and 95 sq mi (250 km ) reservoir make it the largest earth-filled dam in the world. The principal element of the project is an embankment 9,000 feet (2,700 m) long with a maximum height of 465 feet (142 m). The dam used approximately 200 million cubic yards (152.8 million cu. meters) of fill, which makes it one of

3080-474: Is overruled by the senior water rights of the irrigation districts during dry years. TID is currently investigating the feasibility of constructing a large pumped-storage hydroelectric plant on Lake Don Pedro in order to better meet peaking power demands without releasing extra water at New Don Pedro Dam. The proposed Red Mountain Bar Project would involve building a 465-foot (142 m) high dam across

3190-416: Is that some US$ 80 million worth of California gold (equivalent to US$ 2.6 billion today) was sent to France by French prospectors and merchants. A majority of the gold went back to New York City brokerage houses. As the gold rush progressed, local banks and gold dealers issued "banknotes" or "drafts"—locally accepted paper currency—in exchange for gold, and private mints created private gold coins . With

3300-419: Is the focus of one of the most longstanding environmental controversies in United States history. Proponents of the dam's removal, including former Sierra Club president David Brower , suggest raising New Don Pedro Dam to replace the storage that would be lost with the draining of Hetch Hetchy. Increasing the height of New Don Pedro by just 20 feet (6.1 m) would add about 360,000 acre-feet (0.44 km) to

3410-614: The Fugitive Slave Act of 1850 , encouraged the arrival of free blacks and escaped slaves. While the treaty ending the Mexican–American War obliged the United States to honor Mexican land grants, almost all the goldfields were outside those grants. Instead, the goldfields were primarily on " public land ", meaning land formally owned by the United States government. However, there were no legal rules yet in place, and no practical enforcement mechanisms. The benefit to

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3520-465: The Gold Country of California or "Mother Lode" from other countries and from other parts of the United States. As Sutter had feared, his business plans were ruined after his workers left in search of gold, and squatters took over his land and stole his crops and cattle. San Francisco had been a tiny settlement before the rush began. When residents learned about the discovery, it at first became

3630-495: The Gold Rush town of Jacksonville by June. The powerhouse and penstocks were completed by August 1970, after lengthy delays and setbacks due to the sheer scale of the generators, pipes and gates used in their construction. Some of the individual components were so heavy that a truck delivering one of the penstock sections sank up to its trailer bed in the road, and another was crushed when the driver braked, inadvertently snapping

3740-757: The Isthmus of Panama and the steamships of the Pacific Mail Steamship Company . Australians and New Zealanders picked up the news from ships carrying Hawaiian newspapers, and thousands, infected with "gold fever", boarded ships for California. Forty-niners came from Latin America, particularly from the Mexican mining districts near Sonora and Chile. Gold-seekers and merchants from Asia, primarily from China, began arriving in 1849, at first in modest numbers to Gum San (" Gold Mountain "),

3850-662: The Mexican–American War , the Treaty of Cahuenga was signed, leading to the resolution of the military conflict in Alta California (Upper California). On January 24, 1848, James W. Marshall found shiny metal in the tailrace of a lumber mill he was building for Sacramento pioneer John Sutter —known as Sutter's Mill , near Coloma on the American River . Marshall brought what he found to Sutter, and

3960-655: The Sacramento River , sprang into existence and then faded. The Gold Rush town of Weaverville on the Trinity River today retains the oldest continuously used Taoist temple in California, a legacy of Chinese miners who came. While there are not many Gold Rush era ghost towns still in existence, the remains of the once-bustling town of Shasta have been preserved in a California State Historic Park in Northern California. By 1850, most of

4070-543: The San Francisco Bay in 1849, only 700 were women (including those who were poor, wealthy, entrepreneurs, prostitutes, single, and married). They were of various ethnicities including Anglo-American, African-American, Hispanic , Native , European, Chinese, and Jewish. The reasons they came varied: some came with their husbands, refusing to be left behind to fend for themselves, some came because their husbands sent for them, and others came (singles and widows) for

4180-656: The American economy; the sudden population increase allowed California to go rapidly to statehood in the Compromise of 1850 . The gold rush had severe effects on Native Californians and accelerated the Native American population's decline from disease, starvation, and the California genocide . The effects of the gold rush were substantial. Whole indigenous societies were attacked and pushed off their lands by

4290-421: The California foreign miners tax passed in 1851, targeted mainly Latino miners and kept them from making as much money as whites, who did not have any taxes imposed on them. In California most late arrivals made little or wound up losing money. Similarly, many unlucky merchants set up in settlements that disappeared, or which succumbed to one of the calamitous fires that swept the towns that sprang up. By contrast,

4400-764: The MID and TID acquired water rights to the Tuolumne River to secure a water supply for their combined 1,000-square-mile (2,600 km) service area in the San Joaquin Valley . After selling revenue bonds totaling $ 4.1 million, the two irrigation districts began construction of the Don Pedro Dam (now known as Old Don Pedro Dam) in 1921, about one and a half miles (2.4 km) upriver of the present location of New Don Pedro Dam. Upon its completion in 1923, this 284-foot (87 m) concrete gravity arch dam

4510-546: The Methodist church deemed it necessary to send missionaries there to preach the gospel, as churches in that part of the state were not to be found. The first missionary to arrive was William Taylor who arrived in San Francisco in September 1849. For many months he preached in the streets to hundreds of people without salary, and ultimately after saving often generous donations from successful miners, he built and established

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4620-638: The Modocs . The first people to rush to the goldfields, beginning in the spring of 1848, were the residents of California themselves—primarily agriculturally oriented Americans and Europeans living in Northern California , along with Native Californians and some Californios (Spanish-speaking Californians; at the time, commonly referred to in English as simply 'Californians'). These first miners tended to be families in which everyone helped in

4730-533: The Pacific side, wait for a ship sailing for San Francisco. There was also a route across Mexico starting at Veracruz . The companies providing such transportation created vast wealth among their owners and included the U.S. Mail Steamship Company , the federally subsidized Pacific Mail Steamship Company , and the Accessory Transit Company . Many gold-seekers took the overland route across

4840-473: The U.S. Bureau of Reclamation California Gold Rush The California gold rush (1848–1855) was a gold rush that began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California . The news of gold brought approximately 300,000 people to California from the rest of the United States and abroad. The sudden influx of gold into the money supply reinvigorated

4950-547: The adventure and economic opportunities. On the trail many people died from accidents, cholera , fever, and myriad other causes, and many women became widows before even setting eyes on California. While in California, women became widows quite frequently due to mining accidents , disease, or mining disputes of their husbands. Life in the goldfields offered opportunities for women to break from their traditional work. Because of many thousands of people flooding into California at Sacramento and San Francisco and surrounding areas,

5060-637: The asphalt make such dams especially suited to earthquake regions. For the Moglicë Hydro Power Plant in Albania the Norwegian power company Statkraft built an asphalt-core rock-fill dam. Upon completion in 2018 the 320 m long, 150 m high and 460 m wide dam is anticipated to be the world's highest of its kind. A concrete-face rock-fill dam (CFRD) is a rock-fill dam with concrete slabs on its upstream face. This design provides

5170-587: The building of the San Francisco Mint in 1854, gold bullion was turned into official United States gold coins for circulation. The gold was also later sent by California banks to U.S. national banks in exchange for national paper currency to be used in the booming California economy . The arrival of hundreds of thousands of new people in California within a few years, compared to a population of some 15,000 Europeans and Californios beforehand, had many dramatic effects. A 2017 study attributes

5280-534: The chains that held the load in place. "We have harnessed a great river to serve man. There is a vision, imagination, sense of beauty about it. Environment and development will never meet, but a delicate balance of the two has been achieved at Don Pedro Dam." –Joseph Alioto, mayor of San Francisco, at 1971 New Don Pedro Dam dedication The total cost of the New Don Pedro Dam project, including site preparations, reservoir clearing and road relocations,

5390-515: The clear intent to distinguish their higher class power over those that could not afford those accommodations. Supply ships arrived in San Francisco with goods to supply the needs of the growing population. When hundreds of ships were abandoned after their crews deserted to go into the goldfields, many ships were converted to warehouses, stores, taverns, hotels, and one into a jail. As the city expanded and new places were needed on which to build, many ships were destroyed and used as landfill. Within

5500-549: The concrete slab as an impervious wall to prevent leakage and also a structure without concern for uplift pressure. In addition, the CFRD design is flexible for topography, faster to construct and less costly than earth-fill dams. The CFRD concept originated during the California Gold Rush in the 1860s when miners constructed rock-fill timber-face dams for sluice operations . The timber was later replaced by concrete as

5610-445: The construction site. The 3,415-foot (1,041 m) tunnel was fully excavated by March 13 of the following year and lined with reinforced concrete by August. On September 7, a 40-foot (12 m) cofferdam was constructed and the diversion tunnel began to carry the flow of the Tuolumne. As the dam site dried out, the foundations were excavated down to bedrock; cracks in the rock were injected with so-called "dental concrete" to stabilize

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5720-573: The continental United States, particularly along the California Trail . Each of these routes had its own deadly hazards, from shipwreck to typhoid fever and cholera . In the early years of the rush, much of the population growth in the San Francisco area was due to steamship travel from New York City through overland portages in Nicaragua and Panama and then back up by steamship to San Francisco. While traveling, many steamships from

5830-406: The core is separated using a filter. Filters are specifically graded soil designed to prevent the migration of fine grain soil particles. When suitable building material is at hand, transport is minimized, leading to cost savings during construction. Rock-fill dams are resistant to damage from earthquakes . However, inadequate quality control during construction can lead to poor compaction and sand in

5940-551: The dam by 1966, but concerns that the dam would further impact decreasing populations of king salmon in the Tuolumne put a temporary stop to the project. In fact, it was not until that year that the Federal Power Commission (now Federal Energy Regulatory Commission ) licensed the irrigation districts to go ahead on New Don Pedro. The $ 49.7 million primary construction contract for the dam was awarded to Guy F. Atkinson Company on August 22, 1967. When he first saw

6050-406: The dam must be calculated in advance of building to ensure that its break level threshold is not exceeded. Overtopping or overflow of an embankment dam beyond its spillway capacity will cause its eventual failure . The erosion of the dam's material by overtopping runoff will remove masses of material whose weight holds the dam in place and against the hydraulic forces acting to move the dam. Even

6160-497: The dam released more than 50,000 cubic feet per second (1,400 m/s) – almost six times the capacity of downstream levees. The bottom 309,000 acre-feet (0.381 km) is considered dead storage, or the lowest point at which water can be released to generate power. At an elevation of 804 feet (245 m) (service spillway crest), the reservoir is 25 miles (40 km) long, and has an area of 12,960 acres (5,240 ha) with 160 miles (260 km) of shoreline. The maximum elevation of

6270-409: The dam site, chief engineer John Goodier was reported to have said "[it'd be a] tough nut to crack". Clearing the dam site began immediately afterwards, in addition to the construction of access roads and a camp for construction workers. Construction of the dam's service spillway began a week later on August 29. On September 22, 1967, work began on the diversion tunnel that would allow the river to bypass

6380-490: The dam, but embankment dams are prone to seepage through the dam as well; for example, the Usoi landslide dam leaks 35-80 cubic meters per second. Sufficiently fast seepage can dislodge a dam's component particles, which results in faster seepage, which turns into a runaway feedback loop that can destroy the dam in a piping-type failure. Seepage monitoring is therefore an essential safety consideration. gn and Construction in

6490-491: The dam. The core can be of clay, concrete, or asphalt concrete . This type of dam is a good choice for sites with wide valleys. They can be built on hard rock or softer soils. For a rock-fill dam, rock-fill is blasted using explosives to break the rock. Additionally, the rock pieces may need to be crushed into smaller grades to get the right range of size for use in an embankment dam. Earth-fill dams, also called earthen dams, rolled-earth dams or earth dams, are constructed as

6600-456: The design was applied to irrigation and power schemes. As CFRD designs grew in height during the 1960s, the fill was compacted and the slab's horizontal and vertical joints were replaced with improved vertical joints. In the last few decades, design has become popular. The tallest CFRD in the world is the 233 m-tall (764 ft) Shuibuya Dam in China , completed in 2008. The building of

6710-634: The dominant activity held throughout the steamships was gambling, which was ironic because segregation between wealth gaps was prominent throughout the ships. Everything was segregated between the rich vs. the poor. There were different levels of travel one could pay for to get to California. The cheaper steamships tended to have longer routes. In contrast, the more expensive would get passengers to California quicker. There were clear social and economic distinctions between those who traveled together, being that those who spent more money would receive accommodations that others were not allowed. They would do this with

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6820-572: The easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations. Faced with gold increasingly difficult to retrieve, Americans began to drive out foreigners to get at the most accessible gold that remained. The new California State Legislature passed a foreign miners tax of twenty dollars per month ($ 730 per month as of 2024), and American prospectors began organized attacks on foreign miners, particularly Latin Americans and Chinese . In addition,

6930-419: The eastern seaboard required the passengers to bring kits, which were typically full of personal belongings such as clothes, guidebooks, tools, etc. In addition to personal belongings, Argonauts were required to bring barrels full of beef, biscuits, butter, pork, rice, and salt. While on the steamships, travelers could talk to each other, smoke, fish, and other activities depending on the ship they traveled. Still,

7040-404: The effort. Women and children of all ethnicities were often found panning next to the men. Some enterprising families set up boarding houses to accommodate the influx of men; in such cases, the women often brought in steady income while their husbands searched for gold. Word of the gold rush spread slowly at first. The earliest gold-seekers were people who lived near California or people who heard

7150-520: The embankment which can lead to liquefaction of the rock-fill during an earthquake. Liquefaction potential can be reduced by keeping susceptible material from being saturated, and by providing adequate compaction during construction. An example of a rock-fill dam is New Melones Dam in California or the Fierza Dam in Albania . A core that is growing in popularity is asphalt concrete . The majority of such dams are built with rock and/or gravel as

7260-488: The first Methodist church in California, and California's first professional hospital. When the Gold Rush began, the California goldfields were peculiarly lawless places. When gold was discovered at Sutter's Mill, California was still technically part of Mexico, under American military occupation as the result of the Mexican–American War. With the signing of the treaty ending the war on February 2, 1848, California became

7370-437: The first five years of the Gold Rush. In the next stage, by 1853, hydraulic mining was used on ancient gold-bearing gravel beds on hillsides and bluffs in the goldfields. In a modern style of hydraulic mining first developed in California, and later used around the world, a high-pressure hose directed a powerful stream or jet of water at gold-bearing gravel beds. The loosened gravel and gold would then pass over sluices, with

7480-565: The first supply stores in Sacramento, Coloma, and other spots in the goldfields. Just as the rush began, he purchased all the prospecting supplies available in San Francisco and resold them at a substantial profit. Some gold-seekers made a significant amount of money. On average, half the gold-seekers made a modest profit, after taking all expenses into account; economic historians have suggested that white miners were more successful than black, Indian, or Chinese miners. However, taxes such as

7590-669: The foothills of the Sierra Nevada . The New Don Pedro Dam is owned and operated by the Modesto Irrigation District (MID) and Turlock Irrigation District (TID). At 585 feet (178 m) tall, the dam is the tenth highest in the U.S. and its reservoir is the sixth largest artificial lake in California. The original dam was named for the old mining town of Don Pedros Bar on the Tuolumne River, which in turn takes its name from prospector Pierre "Don Pedro" Sainsevain . Shortly after their formation in 1887,

7700-400: The forty-niners was that the gold was simply "free for the taking" at first. In the goldfields at the beginning, there was no private property, no licensing fees, and no taxes . The miners informally adapted Mexican mining law that had existed in California. For example, the rules attempted to balance the rights of early arrivers at a site with later arrivers; a " claim " could be "staked" by

7810-412: The foundation. Construction of the embankment began on September 16, 1968, the dam embankment was placed using bottom dump trailers manufactured by Athey and compacted with rubber tired and vibrating rollers. The dam's massive concrete emergency spillway was completed on January 19, 1969. However, severe flooding on January 26 destroyed the cofferdam and all of the construction site's bridges, putting work

7920-454: The gold in the California gravel beds was so richly concentrated, early forty-niners were able to retrieve loose gold flakes and nuggets with their hands, or simply " pan " for gold in rivers and streams. Panning cannot take place on a large scale, and industrious miners and groups of miners graduated to placer mining , using " cradles " and "rockers" or "long-toms" to process larger volumes of gravel. Miners would also engage in "coyoteing",

8030-559: The gold settling to the bottom where it was collected. By the mid-1880s, it is estimated that 11 million troy ounces (340 t) of gold (worth approximately US$ 15 billion at December 2010 prices) had been recovered by hydraulic mining. A byproduct of these extraction methods was that large amounts of gravel, silt , heavy metals , and other pollutants went into streams and rivers. Court rulings (1882 Gold Run and 1884 "Sawyer Act" ) and 1893 federal legislation limited hydraulic mining in California. As of 1999 many areas still bear

8140-503: The gold was sent to the U.S. Mint , although otherwise attracted little notice. In 1843, Lopez found gold in San Feliciano Canyon near his first discovery. Mexican miners from Sonora worked the placer deposits until 1846. Minor finds of gold in California were also made by Mission Indians prior to 1848. The friars instructed them to keep its location secret to avoid a gold rush . In January 1847, nine months into

8250-440: The gold-bearing quartz. Once the gold-bearing rocks were brought to the surface, the rocks were crushed and the gold separated, either using separation in water, using its density difference from quartz sand, or by washing the sand over copper plates coated with mercury (with which gold forms an amalgam ). Loss of mercury in the amalgamation process was a source of environmental contamination . Eventually, hard-rock mining became

8360-592: The gold-seekers, called "forty-niners" (referring to 1849, the peak year for gold rush immigration). Outside of California, the first to arrive were from Oregon , the Sandwich Islands (Hawaii), and Latin America in late 1848. Of the approximately 300,000 people who came to California during the gold rush, about half arrived by sea and half came overland on the California Trail and the California Road ; forty-niners often faced substantial hardships on

8470-423: The goldfields and find the equivalent of six years' wages back home. Some hoped to get rich quick and return home, and others wished to start businesses in California. By the beginning of 1849, word of the gold rush had spread around the world, and an overwhelming number of gold-seekers and merchants began to arrive from virtually every continent. The largest group of forty-niners in 1849 were Americans, arriving by

8580-659: The hills near Genoa , Italy were among the first to settle permanently in the Sierra Nevada foothills ; they brought with them traditional agricultural skills, developed to survive cold winters. A modest number of miners of African ancestry (probably less than 4,000) had come from the Southern States , the Caribbean and Brazil. A number of immigrants were from China. Several hundred Chinese arrived in California in 1849 and 1850, and in 1852 more than 20,000 landed in San Francisco. Their distinctive dress and appearance

8690-415: The horses grazed, Lopez dug up some wild onions and found a small gold nugget in the roots among the bulbs. He looked further and found more gold. Lopez took the gold to authorities who confirmed its worth. Lopez and others began to search for other streambeds with gold deposits in the area. They found several in the northeastern section of the forest, within present-day Ventura County . In November, some of

8800-638: The huge numbers of newcomers were driving Native Americans out of their traditional hunting, fishing and food-gathering areas. To protect their homes and livelihood, some Native Americans responded by attacking the miners. This provoked counter-attacks on native villages. The Native Americans, out-gunned, were often slaughtered. Those who escaped massacres were many times unable to survive without access to their food-gathering areas, and they starved to death. Novelist and poet Joaquin Miller vividly captured one such attack in his semi-autobiographical work, Life Amongst

8910-453: The integrity of the downstream shell zone. An outdated method of zoned earth dam construction used a hydraulic fill to produce a watertight core. Rolled-earth dams may also employ a watertight facing or core in the manner of a rock-fill dam. The frozen-core dam is a temporary earth dam occasionally used in high latitudes by circulating a coolant through pipes inside the dam to maintain a watertight region of permafrost within it. Tarbela Dam

9020-495: The irrigation districts to construct the new dam. The U.S. Bureau of Reclamation made tentative studies for a high dam on the Tuolumne River as part of its Central Valley Project , though it later dropped the plans in favor of other sites. In 1961, an overwhelming majority of voters in the TID and MID service areas and San Francisco approved bond issues to finance the construction of a new dam. The irrigation districts hoped to complete

9130-449: The largest man-made structures in the world. Because earthen dams can be constructed from local materials, they can be cost-effective in regions where the cost of producing or bringing in concrete would be prohibitive. Rock -fill dams are embankments of compacted free-draining granular earth with an impervious zone. The earth used often contains a high percentage of large particles, hence the term "rock-fill". The impervious zone may be on

9240-511: The late 1890s, dredging technology (also invented in California) had become economical, and it is estimated that more than 20 million troy ounces (620 t) were recovered by dredging. Both during the gold rush and in the decades that followed, gold-seekers also engaged in "hard-rock" mining, extracting the gold directly from the rock that contained it (typically quartz ), usually by digging and blasting to follow and remove veins of

9350-524: The mill to secrecy, in February 1848, Sutter sent Charles Bennett to Monterey to meet with Colonel Mason, the chief U.S. official in California, to secure the mineral rights of the land where the mill stood. Bennett was not to tell anyone of the discovery of gold, but when he stopped at Benicia , he heard talk about the discovery of coal near Mount Diablo, and he blurted out the discovery of gold. He continued to San Francisco, where again, he could not keep

9460-553: The name given to California in Chinese. The first immigrants from Europe, reeling from the effects of the Revolutions of 1848 and with a longer distance to travel, began arriving in late 1849, mostly from France, with some Germans , Italians , and Britons . It is estimated that approximately 90,000 people arrived in California in 1849—about half by land and half by sea. Of these, perhaps 50,000 to 60,000 were Americans, and

9570-412: The need, where he held services in the street, using a barrel head as his pulpit. Crowds would gather to listen to his sermons, and before long he received enough generous donations from successful gold miners and built San Francisco's first church. In what has been referred to as the "first world-class gold rush," there was no easy way to get to California; forty-niners faced hardship and often death on

9680-504: The news from ships on the fastest sailing routes from California. The first large group of Americans to arrive were several thousand Oregonians who came down the Siskiyou Trail. Next came people from the Sandwich Islands , and several thousand Latin Americans, including people from Mexico, from Peru and from as far away as Chile, both by ship and overland. By the end of 1848, some 6,000 Argonauts had come to California. Only

9790-467: The population and economy of California had become large and diverse enough that money could be made in a wide variety of conventional businesses. Once extracted, the gold itself took many paths. First, much of the gold was used locally to purchase food, supplies and lodging for the miners . It also went towards entertainment, which consisted of anything from a traveling theater to alcohol, gambling, and prostitutes. These transactions often took place using

9900-424: The primary fill. Almost 100 dams of this design have now been built worldwide since the first such dam was completed in 1962. All asphalt-concrete core dams built so far have an excellent performance record. The type of asphalt used is a viscoelastic - plastic material that can adjust to the movements and deformations imposed on the embankment as a whole, and to settlement of the foundation. The flexible properties of

10010-404: The project "on hold indefinitely". Embankment dam Embankment dams come in two types: the earth-filled dam (also called an earthen dam or terrain dam ) made of compacted earth, and the rock-filled dam . A cross-section of an embankment dam shows a shape like a bank, or hill. Most have a central section or core composed of an impermeable material to stop water from seeping through

10120-560: The recently recovered gold, carefully weighed out. These merchants and vendors, in turn, used the gold to purchase supplies from ship captains or packers bringing goods to California. The gold then left California aboard ships or mules to go to the makers of the goods from around the world. A second path was the Argonauts themselves who, having personally acquired a sufficient amount, sent the gold home, or returned home taking with them their hard-earned "diggings". For example, one estimate

10230-466: The record-long economic expansion of the United States in the recession-free period of 1841–1856 primarily to "a boom in transportation-goods investment following the discovery of gold in California." The gold rush propelled California from a sleepy, little-known backwater to a center of the global imagination and the destination of hundreds of thousands of people. The new immigrants often showed remarkable inventiveness and civic mindedness. For example, in

10340-440: The reservoir at the crest of the emergency spillway is 830 feet (250 m) above sea level. During construction of the dam, it was anticipated that the large size and scenic location of the reservoir, coupled with its proximity to urban centers, would make it a large tourist draw. A $ 40,000 plan was put forth to develop the reservoir for recreational activities. This entailed the construction of campsites, picnic areas, boat ramps,

10450-501: The reservoir begins to move the entire structure. The embankment, having almost no elastic strength, would begin to break into separate pieces, allowing the impounded reservoir water to flow between them, eroding and removing even more material as it passes through. In the final stages of failure, the remaining pieces of the embankment would offer almost no resistance to the flow of the water and continue to fracture into smaller and smaller sections of earth or rock until they disintegrate into

10560-609: The reservoir's storage capacity, replacing most of the storage in Hetch Hetchy, though new tunnels would have to be built to deliver water from Don Pedro Reservoir to the Hetch Hetchy Aqueduct and there would be a net loss of hydroelectric generation from O'Shaughnessy. Of note is that San Francisco is already entitled to 453,000 acre-feet (0.559 km) of the water stored in Don Pedro, although this allocation

10670-475: The rest were from other countries. By 1855, it is estimated at least 300,000 gold-seekers, merchants, and other immigrants had arrived in California from around the world. The largest group continued to be Americans, but there were tens of thousands each of Mexicans, Chinese, Britons, Australians, French, and Latin Americans, together with many smaller groups of miners, such as African Americans, Filipinos , Basques and Turks . People from small villages in

10780-517: The scars of hydraulic mining, since the resulting exposed earth and downstream gravel deposits do not support plant life. After the gold rush had concluded, gold recovery operations continued. The final stage to recover loose gold was to prospect for gold that had slowly washed down into the flat river bottoms and sandbars of California's Central Valley and other gold-bearing areas of California (such as Scott Valley in Siskiyou County). By

10890-419: The secret. At Monterey, Mason declined to make any judgement of title to lands and mineral rights, and Bennett for the third time revealed the gold discovery. By March 1848, rumors of the discovery were confirmed by San Francisco newspaper publisher and merchant Samuel Brannan . Brannan hurriedly set up a store to sell gold prospecting supplies, and he walked through the streets of San Francisco, holding aloft

11000-442: The service spillway was completed. On May 28, 1970, the embankment was finally topped out with the last of over 250,000 truckloads of material. After the clearing of over 7,000 acres (2,800 ha) of the future reservoir site and the relocation of several roads that ran through it, the diversion tunnel was closed and water began to rise behind New Don Pedro. The rising lake submerged Old Don Pedro Dam on April 12, 1970 and inundated

11110-461: The single largest source of gold produced in the Gold Country . The total production of gold in California from then until now is estimated at 118 million troy ounces (3,700 t). Recent scholarship confirms that merchants made far more money than miners during the gold rush. The wealthiest man in California during the early years of the rush was Samuel Brannan , a tireless self-promoter, shopkeeper and newspaper publisher. Brannan opened

11220-621: The tens of thousands overland across the continent and along various sailing routes (the name "forty-niner" was derived from the year 1849). Many from the East Coast negotiated a crossing of the Appalachian Mountains , taking to riverboats in Pennsylvania , poling the keelboats to Missouri River wagon train assembly ports, and then traveling in a wagon train along the California Trail . Many others came by way of

11330-430: The trip. While most of the newly arrived were Americans, the gold rush attracted thousands from Latin America, Europe, Australia, and China. Agriculture and ranching expanded throughout the state to meet the needs of the settlers. San Francisco grew from a small settlement of about 200 residents in 1846 to a boomtown of about 36,000 by 1852. Roads, churches, schools and other towns were built throughout California. In 1849,

11440-446: The two privately tested the metal. After the tests showed that it was gold, Sutter expressed dismay, wanting to keep the news quiet because he feared what would happen to his plans for an agricultural empire if there were a gold rush in the region. The Mexican–American War ended on May 30 with the ratification of the Treaty of Guadalupe Hidalgo , which formally transferred California to the United States. Having sworn all concerned at

11550-404: The upstream face and made of masonry , concrete , plastic membrane, steel sheet piles, timber or other material. The impervious zone may also be inside the embankment, in which case it is referred to as a "core". In the instances where clay is used as the impervious material, the dam is referred to as a "composite" dam. To prevent internal erosion of clay into the rock fill due to seepage forces,

11660-458: The way. At first, most Argonauts , as they were also known, traveled by sea. From the East Coast, a sailing voyage around the tip of South America would take four to five months, and cover approximately 18,000 nautical miles (21,000 mi; 33,000 km). An alternative was to sail to the Atlantic side of the Isthmus of Panama , take canoes and mules for a week through the jungle, and then on

11770-426: The world. New methods of transportation developed as steamships came into regular service. By 1869, railroads were built from California to the eastern United States. At its peak, technological advances reached a point where significant financing was required, increasing the proportion of gold companies to individual miners. Gold worth tens of billions of today's US dollars was recovered, which led to great wealth for

11880-483: Was $ 115,679,000. The dam was formally dedicated on May 22, 1971 to a crowd of over 3,000 people. Among the dedication ceremonies were a speech by San Francisco mayor Joseph Alioto and a beef barbecue hosted by TID. Rising 585 feet (178 m) above its foundations and 560 feet (170 m) above the Tuolumne River, New Don Pedro is a massive earth and rock fill structure containing 16,750,000 cubic yards (12,810,000 m) of material. The 1,900-foot (580 m) long dam

11990-476: Was highly recognizable in the goldfields. Chinese miners suffered enormously, enduring violent racism from white miners who aimed their frustrations at foreigners. Further animosity toward the Chinese led to legislation such as the Chinese Exclusion Act and Foreign Miners Tax. There were also women in the gold rush . However, their numbers were small. Of the 40,000 people who arrived by ship to

12100-459: Was the highest dam in the world, forming a 289,000-acre-foot (0.356 km) reservoir with a surface area of 3,086 acres (1,249 ha). The dam's 15 megawatt (MW) hydroelectric plant, later expanded to 37.5 MW, delivered its first power in October 1923. Expanding Don Pedro or constructing a new dam altogether was first seriously considered in the 1940s because the existing dam could only store

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