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143-602: The dam is a "run-of-the-river" dam because it can generate electricity without needing to store additional water supplies behind the dam. Black Eagle Falls is the first in a series of five waterfalls which constitute the Great Falls of the Missouri River in the state of Montana in the United States. Before being dammed, water dropped 26.42 feet (8.05 m) over the falls. Black Eagle Falls formed on

286-639: A ballot initiative that would have required the state to buy all of PPL's hydroelectric dams in Montana, including Black Eagle Dam. Montana voters rejected the initiative in November 2002. At the time Montana Power sold Black Eagle Dam to PPL, Montana Power was installing controls that would allow the dam to be remotely operated from Rainbow Dam. At that time, PPL Montana said it had no plans to expand electrical generation capacity at Black Eagle Dam. Also in 1999, Montana Power turned most of Tailrace Island over to

429-653: A fall line unconformity in the Great Falls Tectonic Zone . The Missouri River in this area flows over and through the Kootenai Formation , a mostly nonmarine sandstone laid down by rivers, glaciers, and lakes in the past. Some of the Kootenai Formation is marine, however, laid down by shallow seas. The river is eating away at the softer nonmarine sandstone, with the harder rock forming the falls themselves. The Mandan and

572-942: A parking lot for powerhouse and smelter workers. Ownership of the dam changed twice in the second decade of the 20th century. In 1908, John D. Ryan (president of the Daly Bank and Trust Co. in Butte and the Anaconda Copper Company , and a future Assistant Secretary of War) purchased most of the shares in the GFWPTC. In 1910, GFWPTC organized a subsidiary, the Great Falls Power Co., to take over ownership and operation of Black Eagle Dam and its other hydroelectric properties (then being built). A second ownership change occurred in 1912. Cost overruns on Holter Dam , waning investor enthusiasm for dam-building, and

715-486: A piezometer , manometer , differential manometer, Bourdon gauge , as well as an inclined manometer. As Prasuhn states: The main difference between an ideal fluid and a real fluid is that for ideal flow p 1 = p 2 and for real flow p 1 > p 2 . Ideal fluid is incompressible and has no viscosity. Real fluid has viscosity. Ideal fluid is only an imaginary fluid as all fluids that exist have some viscosity. A viscous fluid will deform continuously under

858-440: A $ 300,000 copper smelter near the dam. Construction began on Black Eagle Dam in 1890. GFWPTC engineers designed a rock-and-timber crib weir overflow dam, in which dressed and shaped heavy timbers formed a closed structure filled with rock or rubble. The dam was not a large one. The goal was to merely create a pond behind the dam, which would create enough water pressure (or " head ") to turn turbines and generate electricity. The dam

1001-546: A $ 6 million museum and education center (which includes an exhibit hall, theater, store, and classrooms) which tells the story of Lewis and Clark's passage through central Montana and their discovery of the Great Falls of the Missouri. Much work has been done in the past two decades to create public access to and public viewing areas of the dam and falls. For decades, two gravel spaces existed on River Drive North near

1144-482: A 0.5-mile-long (0.80 km) section of trail designed to link Art Higgins Memorial Park (on the north bank of the Missouri River just behind the dam) with the island. Most of the construction costs were paid for by PPL Montana. In 2001, another segment of the trail was added, leading from the Black Eagle Memorial Island spur up Smelter Hill. The 2,950-foot-long (900 m) trail was paid for by

1287-588: A Community Transportation Enhancement Project grant. There is no fee to enter Black Eagle Memorial Island, which is open daily to the public from 9 A.M. to 8 P.M. and is maintained by the Montana Department of Fish, Wildlife and Parks. In 2004, the River's Edge Trail was extended along the north bank of the Missouri River from the Black Eagle Dam powerhouse westward about 1.3 miles (2.1 km) to

1430-433: A global testing ground for 10–50 MW run-of-river technology . As of March 2010, there were 628 applications pending for new water licences solely for power generation, representing more than 750 potential points of river diversion. In undeveloped areas, new access roads and transmission lines can cause habitat fragmentation , allowing the introduction of invasive species. Run-of-the-river projects strongly depend on

1573-419: A hearing began before an FPC trial examiner on November 18, 1946, to determine whether the rivers where Montana Power had constructed dams prior to 1935 were navigable and therefore should be licensed under the act. In Opinion No. 170, issued on September 30, 1947, the trial examiner found that the rivers in question were navigable and the dams (including Black Eagle Dam) should be licensed. The company appealed to

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1716-580: A hydraulic engineering project, one must figure out how much water is involved. The hydraulic engineer is concerned with the transport of sediment by the river, the interaction of the water with its alluvial boundary, and the occurrence of scour and deposition. "The hydraulic engineer actually develops conceptual designs for the various features which interact with water such as spillways and outlet works for dams, culverts for highways, canals and related structures for irrigation projects, and cooling-water facilities for thermal power plants ." A few examples of

1859-402: A little distance a beautiful little Island well timbered is situated about the middle of the river. in this Island on a Cottonwood tree an Eagle has placed her nest; a more inaccessible spot I believe she could not have found; for neither man nor beast dare pass those gulphs which separate her little domain from the shores. the water is also broken in such manner as it descends over this pitch that

2002-437: A portion of state lands which must be taxed or leased to provide support for public schools. The plaintiffs argued that PPL Montana and its predecessor, Montana Power, only leased these riverbeds from the state and did not own them. The parents sued to force PPL to pay rent due. (At no time in the past had the state sought rental income from Montana Power, and no payments by Montana Power or PPL Montana had ever been made.) Although

2145-437: A reservoir about 2 miles (3.2 km) long behind it. The reservoir behind the first dam was about 17 feet (5.2 m) deep immediately behind the dam, and contained 459.1 acre-feet (566,300 m) of water behind it. The current dam has a storage capacity of 1,710 acre-feet (2,110,000 m) to 1,820 acre-feet (2,240,000 m) of water. The reservoir formed behind Black Eagle Dam has no official name. However, due to

2288-754: A respectable position in China. In the Archaic epoch of the Philippines , hydraulic engineering also developed specially in the Island of Luzon , the Ifugaos of the mountainous region of the Cordilleras built irrigations, dams and hydraulic works and the famous Banaue Rice Terraces as a way for assisting in growing crops around 1000 BC. These Rice Terraces are 2,000-year-old terraces that were carved into

2431-471: A river's flow (up to 95% of mean annual discharge) through a pipe and/or tunnel leading to electricity-generating turbines, then return the water back to the river downstream. Run-of-the-river projects are dramatically different in design and appearance from conventional hydroelectric projects. Traditional hydroelectric dams store enormous quantities of water in reservoirs , sometimes flooding large tracts of land. In contrast, run-of-river projects do not have

2574-632: A second powerhouse just downstream of its existing south bank powerhouse. This powerhouse mechanically transferred power to the Royal Milling Company flour mill on the bluff above. In 1897, GFWPTC built yet another powerhouse (this time next to its north bank powerhouse) to supply even more power to the smelter above. On April 14, 1908, at about 2:30 PM, Hauser Dam —a steel dam about 90 miles upstream from Great Falls— failed. A surge of water 25 feet (7.6 m) to 30 feet (9.1 m) high swept downstream. A Great Northern Railway locomotive

2717-399: A shear force by the pascles law, whereas an ideal fluid does not deform. The various effects of disturbance on a viscous flow are a stable, transition and unstable. For an ideal fluid, Bernoulli's equation holds along streamlines. As the flow comes into contact with the plate, the layer of fluid actually "adheres" to a solid surface. There is then a considerable shearing action between

2860-593: A stir in Great Falls in June 2006, when local residents driving on a nearby road mistook the vehicle for a sport utility vehicle which had fallen into the water.) Ice is another form of dangerous debris for the dam. In December 2010, blocks of floating ice overwhelmed the top of the dam, tearing the handrails off the maintenance walkway. For many years, Black Eagle Dam's owners were required to hold simulations every five years to plan for various kinds of emergencies (flood, sabotage, mechanical breakdown, etc.) which might affect

3003-648: A technique known as hushing , and applied the methods to other ores such as those of tin and lead . In the 15th century, the Somali Ajuran Empire was the only hydraulic empire in Africa. As a hydraulic empire, the Ajuran State monopolized the water resources of the Jubba and Shebelle Rivers . Through hydraulic engineering, it also constructed many of the limestone wells and cisterns of

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3146-447: A thin, viscosity-dominated boundary layer near solid surfaces, and an effectively inviscid outer zone away from the boundaries. This concept explained many former paradoxes and enabled subsequent engineers to analyze far more complex flows. However, we still have no complete theory for the nature of turbulence, and so modern fluid mechanics continues to be combination of experimental results and theory. The modern hydraulic engineer uses

3289-488: Is a 'navigable water of the United States,' and hence subject to the licensing requirements of the Federal Power Act." The court of appeals held that Black Eagle, Morony, Rainbow, and Ryan dams were on navigable waters and occupied public land without any authority. Hauser Dam was on navigable waters and held an invalid license to occupy public land. Holter Dam had a valid license, but that license did not extend to

3432-492: Is a type of hydroelectric generation plant whereby little or no water storage is provided. Run-of-the-river power plants may have no water storage at all or a limited amount of storage, in which case the storage reservoir is referred to as pondage . A plant without pondage is subject to seasonal river flows, so the plant will operate as an intermittent energy source . Conventional hydro uses reservoirs , which regulate water for flood control , dispatchable electrical power , and

3575-520: Is also available on the north shore of the Missouri River from below Black Eagle Dam to Morony Dam . Most of this land is owned by PPL Montana, but there is some private land here which is not open to hunting. The PPL Montana lands are open to hunting due to a conservation easement, but the Montana Department of Fish, Wildlife and Parks requires hunters to obtain a map of these lands before using them for hunting. There are also restrictions on

3718-417: Is considered an "unfirm" source of power: a run-of-the-river project has little or no capacity for energy storage and so cannot co-ordinate the output of electricity generation to match consumer demand. It thus generates much more power when seasonal river flows are high (spring freshet ), and depending on location, much less during drier summer months or frozen winter months. Depending on location and type,

3861-501: Is generally used to cover exclusively short-term peak times electricity demand. Diversion Weir is also heavily dependent on the natural river flow. Similar to a regular dam, water is stored from lull periods to be used during peak-times. This allows for the pondage dams to provide for the regulation of daily and/or weekly flows depending on location. When developed with care to footprint size and location, run-of-the-river hydro projects can create sustainable energy minimizing impacts to

4004-441: Is rated at 1,853 MW. Some run-of-the-river projects are downstream of other dams and reservoirs. The reservoir was not built by the project but takes advantage of the water supplied by it. An example would be the 1995 1,436 MW La Grande-1 generating station . Previous upstream dams and reservoirs were part of the 1980s James Bay Project . There are also small and somewhat-mobile forms of a run-of-the-river power plants. One example

4147-673: Is the so-called electricity buoy , a small floating hydroelectric power plant . Like most buoys, it is anchored to the ground, in this case in a river. The energy within the moving water propels a power generator and thereby creates electricity. Prototypes by commercial producers are generating power on the Middle Rhine river in Germany and on the Danube river in Austria. The advantages and disadvantages of run-of-river dams depends on

4290-646: Is true for many of our world's largest cities. In much the same way, the central valley of California could not have become such an important agricultural region without effective water management and distribution for irrigation. In a somewhat parallel way to what happened in California, the creation of the Tennessee Valley Authority (TVA) brought work and prosperity to the South by building dams to generate cheap electricity and control flooding in

4433-733: The Federal Power Act in 1950. The controversy arose in December 1937 when the Federal Power Commission (FPC) began a proceeding (FPC Docket #IT-5840) to license all dams built prior to 1935 (the year the Federal Power Act became law). The act gave the Federal Power Commission the authority to license all dams on navigable waters in the United States. After almost a decade of extensive research and data collection as well as unfruitful negotiations,

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4576-763: The Montana Constitution , and that the district court's calculation of payments due was appropriate. PPL Montana, appealed to the Supreme Court of the United States , and in November 2010 the Supreme Court asked the United States Solicitor General for the views of the federal government. Finally, on February 22, 2012, the U.S. Supreme Court held in PPL Montana v. Montana (No. 10–218, dec. February 22, 2012) that

4719-650: The Montana Power Company . That same year, most of Black Eagle Dam's power (3.9 MW to 5.7 MW) was delivered to the new smelter. In comparison, only about 0.7 MW was delivered to the nearby city. Another 300 horsepower of mechanical energy was created by a water wheel and delivered physically, through a rope and pulley system, to the Royal Milling Co. In 1913, Montana Power upgraded Black Eagle Dam to generate more electrical (rather than mechanical) power. It abandoned its second powerhouse on

4862-552: The South Piegan Blackfeet , among other Native Americans , knew of the falls. On June 13, 1805, Meriwether Lewis of the Lewis and Clark Expedition became the first white person to see the Great Falls (the largest of the five waterfalls). On the second day that the expedition camped near the series of falls, Meriwether Lewis discovered Black Eagle Falls. "I arrived at another cataract of 26 feet...below this fall at

5005-915: The disadvantages associated with reservoirs and so cause fewer environmental impacts. The use of the term "run-of-the-river" for power projects varies around the world. Some may consider a project run-of-the-river if power is produced with no water storage, but limited storage is considered run-of-the-river by others. Developers may mislabel a project run-of-the-river to soothe public perception about its environmental or social effects. The European Network of Transmission System Operators for Electricity distinguishes run-of-the-river and pondage hydropower plants, which can hold enough water to allow generation for up to 24 hours (reservoir capacity / generating capacity ≤ 24 hours), from reservoir hydropower plants, which hold far more than 24 hours of generation without pumps. The Bureau of Indian Standards describes run-of-the-river hydroelectricity as: A power station utilizing

5148-449: The windmill from Islamic Afghanistan . Other original Islamic developments included the saqiya with a flywheel effect from Islamic Spain, the reciprocating suction pump and crankshaft - connecting rod mechanism from Iraq , and the geared and hydropowered water supply system from Syria . In many respects, the fundamentals of hydraulic engineering have not changed since ancient times. Liquids are still moved for

5291-454: The "Scum River" due to the heavy load of sediment, nutrients, and unhealthy aquatic plant growth (such as algae) it contains. The Sun River is the color of chocolate milk where it enters the relatively blue waters of the Missouri, and it leaves the Missouri noticeably muddier. Silt has reduced the reservoir's capacity, filled up the forebay, and caused damage to the powerplant. In 1988, the Montana Department of Environmental Quality (MDEQ) listed

5434-594: The ' water management technological complex ' which was central to the Islamic Green Revolution . The various components of this 'toolkit' were developed in different parts of the Afro-Eurasian landmass, both within and beyond the Islamic world. However, it was in the medieval Islamic lands where the technological complex was assembled and standardized, and subsequently diffused to the rest of

5577-812: The 15th Street Bridge. About $ 175,000 of the $ 204,500 cost of the extension was paid for by the Community Transportation Enhancement Program, and the remainder by the Montana Air Congestion Initiative (a state program), the American Public Land Exchange (a nonprofit organization), and Recreational Trails (a nonprofit which manages the trail). Black Eagle Memorial Island opened to the public on June 2, 2005. Run-of-the-river hydroelectricity Run-of-river hydroelectricity ( ROR ) or run-of-the-river hydroelectricity

5720-470: The 17th and 18th centuries found the inviscid flow solutions unsuitable, and by experimentation they developed empirical equations, thus establishing the science of hydraulics. Late in the 19th century, the importance of dimensionless numbers and their relationship to turbulence was recognized, and dimensional analysis was born. In 1904 Ludwig Prandtl published a key paper, proposing that the flow fields of low-viscosity fluids be divided into two zones, namely

5863-730: The 1964 event did no damage to Black Eagle Dam. (Mel Ruder was awarded a Pulitzer Prize for Breaking News Reporting for his coverage of the flood.) A third major flood occurred on June 21, 1975. More than 2 inches (5.1 cm) of rain fell in the Rocky Mountains in a 24-hour period. More than 5,000 people were evacuated from their homes in Great Falls after the Sun River rose to 21 feet (6.4 m) (6 feet (1.8 m) above flood stage). More than $ 17 million in damage occurred, and 21,000 acres (8,500 ha) were submerged. Floodwaters almost overwhelmed Black Eagle Dam, but no damage to

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6006-543: The Bob Speck Municipal Golf Course where drivers could stop, get out, and view Black Eagle Falls and the dam. In 1991, the River's Edge Trail, a paved and gravel pedestrian recreational trail , opened along tracks of the former Burlington Northern Railroad on the south bank of the Missouri River at Black Eagle Dam. In 2001, Tailrace Island was renamed Black Eagle Memorial Island (in honor of those workers who lost their lives while working on or at

6149-771: The EPA, include antimony , arsenic , cadmium , chromium, cobalt , copper , iron, lead , manganese , mercury, nickel , silver , sodium , and zinc. The area around the falls, despite its urban setting, is a habitat for many animal and bird species. Among the birds commonly found in the area are bald eagles , California gulls , Canada geese , cliff swallows , eared grebes , egrets , golden eagles , American goldfinches , gray catbirds , house wrens , ibises , ospreys , red-necked grebes , sandhill cranes , snow geese , tundra swans , turkey vultures , western grebes , western meadowlarks , white pelicans , and numerous species of duck , owl , and warbler . Common animal species in

6292-602: The Great Falls ( Ryan Dam ), and a third dam ( Cochrane Dam ) between the other two in a canyon of the Missouri River. In 1914, Montana Power considered raising the height of Black Eagle Dam to increase its power generation capacity. In 1916, much of the Boston and Montana smelter plant was replaced by a modern copper and zinc smelter, and a wire and cable manufacturing plant was added. But Black Eagle Dam, even with upgrades to its turbines and other power generation equipment, still only generated about three MW of electricity. More power

6435-665: The Long Pool and Missouri River watershed in this area for future improvement. In 2011, the former smelter next to Black Eagle Dam was listed by the United States Environmental Protection Agency (EPA) as a Superfund hazardous and toxic waste site. The EPA also said it would begin sampling for the riverbed above and below Black Eagle Dam, as well as residential areas in the town of Black Eagle, for heavy metals contamination. Historic records show that plant wastes were routinely dumped into

6578-637: The Middle East and Africa . Controlling the movement and supply of water for growing food has been used for many thousands of years. One of the earliest hydraulic machines, the water clock was used in the early 2nd millennium BC. Other early examples of using gravity to move water include the Qanat system in ancient Persia and the very similar Turpan water system in ancient China as well as irrigation canals in Peru. In ancient China , hydraulic engineering

6721-403: The Missouri River below Black Eagle dam. MDEQ estimated in 2002 that between 27,500,000 cubic yards (21,000,000 m) and 31,000,000 cubic yards (24,000,000 m) of waste were dumped into the river between 1892 and 1915. EPA samples indicated that the contamination could extend as far downstream as Fort Benton , 34 miles (55 km) away. Toxins present in the water and riverbed, according to

6864-615: The Missouri River from the Sun River to Rainbow Dam (just downstream from Black Eagle Dam) as "impaired" under Section 303(d) of the 1972 Clean Water Act due to sediment and suspended solids in the river. Black Eagle Dam (which slows the water and allows sediment to fall to the bottom of the reservoir) has been listed as one of the contributing sources of this problem. To combat this problem, in 1994 seven federal agencies, eight state agencies, 10 local Montana governments, four environmental organizations, and several Montana landowners began working together to reduce nutrient and sediment flows into

7007-489: The Missouri River to rise 4.1 feet (1.2 m) above flood stage. No damage to the dam was reported. On June 10, 1964, heavy rains in the Rocky Mountains caused the Missouri River to rise 9.6 feet (2.9 m) above flood stage—1.5 feet (0.46 m) higher than the 1908 flood. Swift Dam on Birch Creek collapsed, killing 19 people. Lower Two Medicine Lake Dam also collapsed, killing nine. Although 3,000 people were forced out of their homes in Great Falls due to heavy flooding,

7150-607: The Montana Company (a mine holding company), and C. X. Larrabee (owner of the highly productive and famous Larrabee and Mountain View mines). On September 12, 1889, the Boston and Montana signed an agreement with GFWPTC in which the power company agreed to build a dam that would supply the mining firm with at least 1,000 horsepower (or 0.75 MW) of power by September 1, 1890, and 5,000 horsepower (or 3.73 MW) of power by January 1, 1891. In exchange, Boston and Montana agreed to build

7293-486: The Montana Supreme Court had erred in finding all of the riverbeds beneath all PPL Montana dams navigable. The unanimous U.S. Supreme Court held that the correct test is whether the portion of the riverbed under each specific dam (not the entire river, nor even a large or small portion of a river) was navigable at the time of statehood. If it was, then the riverbed is "navigable" and may be taxed. The case

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7436-472: The Old World. Under the rule of a single Islamic caliphate , different regional hydraulic technologies were assembled into "an identifiable water management technological complex that was to have a global impact." The various components of this complex included canals , dams , the qanat system from Persia, regional water-lifting devices such as the noria , shaduf and screwpump from Egypt , and

7579-685: The Sun River and its primary tributaries (Muddy Creek and Careless Creek). About $ 623,500 of Clean Water Act funds, $ 2 million in other federal funds, and $ 2.5 million in state and local funds were used to restore streambank vegetation, improve streamside grazing practices, restore sloping to streambanks, and improve irrigation practices. The program has seen success: By 2010, after just four years of abatement, sediment load dropped by 75 percent in Muddy Creek and 25 percent in Careless Creek. Black Eagle Falls are not always flowing due to

7722-520: The Tailrace Island bridge. On November 2, 1999, Montana Power announced it was selling all of its dams and other electric power generating plants to PPL, Inc. for $ 1.6 billion. The sale, which included Black Eagle Dam, was expected to generate $ 30 million in taxes for the state of Montana (although MPC said the total would be lower). In November 2001, citizens of Montana—upset with energy price increases announced by PPL—sought passage of

7865-465: The area include beavers , mule deer , muskrats , river otters , and white-tailed deer . Beavers are so common in the area that officials consider them pests, and trees in city parks have had to be protected against them. (At one point, beavers were chewing down two trees nightly on Black Eagle Memorial Island. These included two red oak trees found growing on the hill above the dam—the only two red oak trees in northcentral Montana). As of 2006, most of

8008-566: The black eagle which Lewis saw on June 14, 1805. In 1872, Thomas P. Roberts, a survey engineer for the Northern Pacific Railway , formally named the cataract "Black Eagle Falls" after the incident recorded in Lewis' journal. The Great Falls Water Power & Townsite Company was formed in 1887, with the goal of developing the town of Great Falls; providing it with power, sewage, and water; and attracting commerce and industry to

8151-864: The boundary layer is free of shear and viscous-related forces so it is assumed to act as an ideal fluid. The intermolecular cohesive forces in a fluid are not great enough to hold fluid together. Hence a fluid will flow under the action of the slightest stress and flow will continue as long as the stress is present. The flow inside the layer can be either vicious or turbulent, depending on Reynolds number. Common topics of design for hydraulic engineers include hydraulic structures such as dams , levees , water distribution networks including both domestic and fire water supply, distribution and automatic sprinkler systems, water collection networks, sewage collection networks, storm water management, sediment transport , and various other topics related to transportation engineering and geotechnical engineering . Equations developed from

8294-705: The case) in March 1951. Montana Power subsequently sought and won licenses for Black Eagle Dam and the seven others required to do so by the court's ruling. (Black Eagle dam was relicensed by the Federal Energy Regulatory Commission , the successor agency to the FPC, on September 27, 2000 for 40 years. The license, number P-2188, is for PPL's entire Upper Missouri-Madison project.) The three Allis-Chalmers generators were rewound in 1978, and again in 1982. In 1997, Montana Power repainted and renovated

8437-437: The city of Great Falls for use as a recreation area. In addition, Montana Power and ARCO (the successor company to the Boston and Montana) laid 18 inches (46 cm) of topsoil on the island, spent $ 500,000 to landscape it and enhance the safety perimeter around the powerhouse, and agreed to fund a portion of the island's annual upkeep. In the late 1990s, historian Stephen Ambrose suggested removing Black Eagle Dam to restore

8580-516: The city. Railroad magnate James J. Hill organized the investors, who were primary owners of large amounts of stock in the Great Northern Railway . It was capitalized at $ 5 million. Hill sold stock to many of his friends, including Philip Danforth Armour , Charles Arthur Broadwater , Marshall Field , John Murray Forbes , Daniel Willis James , John Stewart Kennedy , Leonard Lewisohn and Charles Elliott Perkins . One of

8723-520: The consistent flow of water, as they lack reservoirs and depend on the natural flow of rivers. Consequently, these projects are more vulnerable to climate change compared to storage-based projects. Short-term climate anomalies such as the El Niño Southern Oscillation (ENSO) [1] can significantly disrupt the flow and can have a profound impact on the operation of these projects. Thus, incorporating climate change considerations into

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8866-572: The dam and public safety. After the September 11 attacks , these exercises were required to happen every year. PPL Montana works with local and state government and law enforcement, other companies, and the news media to plan for various contingencies and improve how it might respond in a disaster or emergency. Taxation of the dam has been an issue of contention since 2000. During the 2002 ballot initiative fight, PPL Montana said its dams were worth at least $ 767 million. But in 2003, PPL argued that

9009-518: The dam or obstruct the penstock intakes. Driftwood and logs are the most common forms of debris, but unusual objects such as boat docks , bowling balls , canoes , hot tubs , and small wooden and steel sheds and buildings also sometimes become lodged against the dam. Removing hollow items can be dangerous, because the water pressure against them can cause them to implode. In addition to large amounts of driftwood, about 100 animal carcasses (cattle, deer, dogs, and various small animals) become lodged against

9152-470: The dam or the penstock intake screens each year. Floating screens at the entrance to the forebay catch many items, as do the penstock intake screens. Workers use a crane to remove items from these screens, and bury the items retrieved at a landfill. Dam operators also use a yellow civilian version of the Alvis Stalwart amphibious vehicle to remove objects, and to maintain the dam. (This vehicle caused

9295-560: The dam or through the penstocks and turbines. Fish "go right through the turbines, it doesn't seem to bother them," dam operators say. Since 1988, the Long Pool and the Missouri River in and around the city of Great Falls have been listed as an "impaired" waterway under the 1972 Clean Water Act. This area was first listed as impaired due to sedimentation, siltation, and suspended solids in 1988. High levels of chromium , mercury , and selenium were listed as impairing factors in 1992. High turbidity (haziness of water due to suspended particles)

9438-466: The dam to break up on the waterfalls below. The pedestrian suspension bridge over the dam also washed out. (A plaque was placed on the 6th Street underpass to mark the extent of the high water. It can be seen there today.) The dam itself suffered some damage as well. This damage was repaired, and the old wooden bridge to Tailrace Island replaced with a single-span steel Warren truss bridge capable of handling automobiles. The island now began to also serve as

9581-456: The dam's power generation requirements and water levels permit it. In May 2001, PPL Montana said it would shut down Black Eagle Falls after July 4 because of water flows only about 40 percent of normal. Reservoir levels were lowered again in September 2004 to repair flashboards. The lack of water exposed the Missouri's original channel near Giant Springs . The reservoir was drawn down again and

9724-505: The dam) and turned over to the River's Edge Trail. A new 10-mile-long (16 km) section of the trail linking the existing 14-mile-long (23 km) trail was also opened that year. The same year, a public boathouse was constructed on Black Eagle Memorial Island for use by canoeists, kayakers, and other watercraft; observation decks; public restrooms; and parking lot. The boat landing was completed in October 2001. Construction also began on

9867-422: The dam, a face (at a pitch of 1:08:1) extended for about 8 feet (2.4 m) before it became vertical. A 30-foot-high (9.1 m) masonry wall was built on the south end of the dam to form the foundation of and to protect the powerhouse, and the construction worked inward from either end of the dam. Every 48 feet (15 m) across the face of the dam, a 14-foot-wide (4.3 m) floodwater spillway made of concrete

10010-548: The dam. Coffer dams were constructed in April 1890 to divert the river from the work areas. Work on the dam itself began on April 15. A shanty town named "River Bank" was constructed just upstream of the construction site on the north bank for the river to house the Croat , Scandinavian , Slovak , and Welsh workers who helped construct the dam. (Most of these workers helped found the town of Black Eagle , and earthen foundations for

10153-401: The dams were worth much less. PPL Montana challenged the amount of property taxes assessed on Black Eagle and its four other dams in the area, protesting 10.87 percent of the $ 4.48 million 2000 tax assessment, 6.5 percent of the $ 4.8 million 2001 tax assessment, and 85.65 percent of the $ 4.96 million tax assessment. This amounted to 30 percent of its total property tax assessment in

10296-562: The discovery of the Great Falls), focuses on events held around Black Eagle and other dams on the Great Falls of the Missouri. In mid-July, the River's Edge Trail Luminaria Walk occurs around Black Eagle Dam and the falls, and are illuminated with colored spotlights during the event. On May 5, 1998, the United States Forest Service opened the 25,000-square-foot (2,300 m) Lewis and Clark Interpretive Center,

10439-445: The dreamt-of power. The company immediately began purchasing riverside land and water rights along the Missouri River from Black Eagle Falls down to Sheep Creek (a distance of about 12 miles (19 km)). In time, it owned almost all the land set aside for the city of Great Falls as well as an additional 5,000 acres (2,000 ha) of waterside property. GFWPTC employed J.T. Fanning, a hydraulic engineer , to survey Black Eagle Falls in

10582-412: The electricity needed by consumers and industry. Moreover, run-of-the-river hydroelectric plants do not have reservoirs, thus eliminating the methane and carbon dioxide emissions caused by the decomposition of organic matter in the reservoir of a conventional hydroelectric dam. That is a particular advantage in tropical countries, where methane generation can be a problem. Without a reservoir, flooding of

10725-443: The falls to their original condition. Refurbishment of power generation and transmission systems at Black Eagle Dam began in 2010. In June of that year, PPL Montana initiated a $ 55 million effort to replace overhead power lines connecting the dam to the area's electric grid. The new power lines (which replaced equipment more than 80 years old) were more widely spaced apart, to permit large birds to pass safely through or perch on

10868-403: The falls turned off in June and July 2008. Flashboards on the dam were removed after a heavy rain to allow runoff to pass over the dam. Once the runoff passed, the flashboards were replaced. But little water remained in the reservoir and river, and the falls ran dry for several days until the reservoir filled again. Because Black Eagle Dam is an overflow dam, it is common for debris to jam against

11011-506: The federal suit was dismissed for lack of a federal issue, PPL Montana filed suit in Montana's First Judicial District Court seeking a declaratory judgment in its favor, arguing that the Federal Power Act preempts the parents' suit and denies states the power to make companies pay for the use of riverbeds. The state district court held against PPL's request for summary judgment on all counts. The two parties then went to trial, which lasted from October 22 to October 30, 2007. On June 13, 2008,

11154-454: The first dam. The south forebay would be abandoned, while the north forebay would be retained (and significantly rehabilitated). The 1897 north bank powerhouse was demolished, and a new, concrete powerhouse built on the same location. The design and location of the new powerhouse was influenced by the company's experiences during the June 1908 flood (during which its south bank powerhouses had been flooded and damaged). Work began that summer with

11297-417: The fish still are plentiful in the area. Rainbow trout are also plentiful upstream from the dam. The area below Black Eagle Falls has been rated by one guide as a good area for fly fishing smallmouth bass and walleye . For many years, the state of Montana managed the Long Pool reservoir as part of one fishing management area, and the river below the dam as part of another. This was changed in 1999, so that

11440-538: The fluid's surroundings. This pressure, measured in N/m , is not constant throughout the body of fluid. Pressure, p, in a given body of fluid, increases with an increase in depth. Where the upward force on a body acts on the base and can be found by the equation: where, Rearranging this equation gives you the pressure head p ρ g = y {\displaystyle {\frac {p}{\rho g}}=y} . Four basic devices for pressure measurement are

11583-415: The forebay and tailrace. The new forebay was 421 feet (128 m) long and 96 feet (29 m) wide. The forebay was slightly extended downstream to the new powerhouse, and brick arches of the old powerhouse incorporated into the forebay's walls. The new powerhouse contained three vertical Kaplan turbines (supplied by the S. Morgan Smith Company ) capable of generating 18 MW of power, which gave Black Eagle

11726-616: The full FPC, which began holding hearings on February 16, 1948. When the full FPC found against Montana Power, the company appealed to the United States Court of Appeals for the District of Columbia Circuit . On October 4, 1950, Judge David L. Bazelon , writing for a 2-to-1 majority, held in Montana Power Co. v. Federal Power Commission that "the 263 mile stretch of the Missouri River from Fort Benton to Three Forks

11869-437: The fundamental principles of hydraulic engineering include fluid mechanics , fluid flow, behavior of real fluids, hydrology , pipelines, open channel hydraulics, mechanics of sediment transport, physical modeling, hydraulic machines, and drainage hydraulics. Fundamentals of Hydraulic Engineering defines hydrostatics as the study of fluids at rest. In a fluid at rest, there exists a force, known as pressure, that acts upon

12012-408: The initial design and location selection of run-of-the-river projects can help mitigate the vulnerability of these projects to climate-related disruptions. Hydraulic engineering Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids , principally water and sewage. One feature of these systems is the extensive use of gravity as

12155-409: The island to connect the powerhouse with the smelter above. The north bank and a masonry wall offshore formed a long, concrete-lined forebay (100 feet (30 m) across at its widest part) for the northern powerhouse. The flow of water into this forebay was also controlled by gates. Three iron-enclosed penstocks were built to feed the northern powerhouse. The mechanical power generated by the turbines in

12298-400: The largest generating capacity of any of Montana Power's five dams in the Great Falls area. The Smith company also made the oil-pressure governors (which regulated each turbine's speed) and draft tubes (which slowed the water down as it left the turbine, allowing the faster-moving water above to keep imparting energy to the turbine's propellers). The scroll-shaped inlets and wicket gates around

12441-418: The layer of fluid on the plate surface and the second layer of fluid. The second layer is therefore forced to decelerate (though it is not quite brought to rest), creating a shearing action with the third layer of fluid, and so on. As the fluid passes further along with the plate, the zone in which shearing action occurs tends to spread further outwards. This zone is known as the "boundary layer". The flow outside

12584-662: The liability associated with the collapse of Hauser Dam nearly drove Samuel Thomas Hauser , the largest shareholder in the United Missouri River Power Company (owner of Hauser and Holter) into bankruptcy. Hauser sold his interest in United Missouri River Power to John D. Ryan, who on October 25, 1912, merged United Missouri River Power with the Great Falls Power Co., Butte Electric and Power Company, Billings and Eastern Montana Power Company, and Madison River Power Company to form

12727-432: The mist or sprey rises to a considerable height. this fall is certainly much the greatest I ever beheld except those two which I have mentioned below. it is incomparably a greater cataract and a more noble interesting object than the celebrated falls of Potomac or Soolkiln &c." It is unclear which member of the expedition named the falls, but the expedition called them "Upper Pitch." The falls were eventually named for

12870-540: The most part by gravity through systems of canals and aqueducts, though the supply reservoirs may now be filled using pumps. The need for water has steadily increased from ancient times and the role of the hydraulic engineer is a critical one in supplying it. For example, without the efforts of people like William Mulholland the Los Angeles area would not have been able to grow as it has because it simply does not have enough local water to support its population. The same

13013-443: The motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges , dams , channels , canals , and levees , and to both sanitary and environmental engineering . Hydraulic engineering is the application of the principles of fluid mechanics to problems dealing with the collection, storage, control, transport, regulation, measurement, and use of water. Before beginning

13156-531: The mountains of Ifugao in the Philippines by ancestors of the indigenous people . The Rice Terraces are commonly referred to as the " Eighth Wonder of the World ". It is commonly thought that the terraces were built with minimal equipment, largely by hand. The terraces are located approximately 1500 metres (5000 ft) above sea level. They are fed by an ancient irrigation system from the rainforests above

13299-456: The name, and the name was in popular use as early as 1891 and as late as 1917. Modern historians have referred to it as such, and it was in use by power industry publications as late as 1949. Today, the area from the 1st Avenue North Bridge to the confluence of the Missouri with the Sun River (a distance of about 1 mile (1.6 km)) is known as Broadwater Bay (after Charles Arthur Broadwater,

13442-414: The navigable waters which it used. Hebgen and Madison dams were on non-navigable waters, but occupied public land without a valid license. The court of appeals remanded the issue of Canyon Ferry Dam back to the district court, as that dam had recently been sold to the federal government. Montana Power appealed the decision to the Supreme Court of the United States , which denied certiorari (refused to hear

13585-666: The needs of Black Eagle Dam. Typical median water flows of 11,200 cubic feet (320 m) per second occur in the Missouri River in May of each year. In October 2000, water levels behind the dam were drawn down and the falls shut off for about four weeks while PPL Montana made repairs to the forebay, gates, forebay, and penstock screens. PPL Montana's license for the dam requires it to send at least 200 cubic feet (5.7 m) per second of water over Black Eagle Dam between 9 A.M. and 8 P.M. on weekends and holidays between Memorial Day and Labor Day , although water may flow (and flow at higher rates) if

13728-485: The north powerhouse was not converted into electricity, however. Most of the power was transferred mechanically to the smelter's equipment via a system of ropes and pulleys. Thomson-Houston generators were used to transform some of the mechanical energy generated by the two powerhouses into electricity. A single person could operate the powerhouse during an eight-hour shift. A secondary powerhouse, which contained an Armington & Sims steam-powered turbine and generator,

13871-433: The north shore of the Missouri River below Black Eagle Dam was undeveloped as far down a Sulphur Spring (a distance of about 18 kilometres (11 mi)). Known as the Lewis and Clark Greenway, this area is under a permanent conservation easement . Although the area below Black Eagle Dam is open for bird hunting, the reservoir and river upstream from Black Eagle Dam to Sand Coulee Creek is a no-hunting area. Wildlife hunting

14014-550: The noted Montana railroad executive, real estate investor, and banker). After the dam's reconstruction in 1926, workers and local people were permitted to walk across the top of the dam as a means of getting to work and school. For security reasons, the Montana Power Company closed the dam to such foot traffic during World War II and never allowed it to resume afterward. Montana Power was forced to license Black Eagle Dam and most of its other hydroelectric dams under

14157-433: The plant will most likely have a lower head of water than from a dam, and will thus generate less power. The potential power at a site is a result of the head and flow of water. By damming a river, the head is available to generate power at the face of the dam. A dam may create a reservoir hundreds of kilometres long, but in run-of-the-river the head is usually delivered by a canal, pipe or tunnel constructed upstream of

14300-442: The power house. The cost of upstream construction makes a steep drop desirable, such as falls or rapids. Small, well-sited run-of-the-river projects can be developed with minimal environmental impacts. Larger projects have more environmental concerns. For fish-bearing rivers, a ladder may be required, and dissolved gases downstream may affect fish. In British Columbia , the mountainous terrain and wealth of big rivers have made it

14443-399: The power lines. PPL also said it was replacing the electrical substation next to the dam's powerhouse. Both projects are expected to be complete in 2012. Sediment load carried by the Missouri River and its tributaries is a problem for Black Eagle Dam. The Sun River joins the Missouri River just a few miles upstream from Black Eagle Dam. The Sun River has long been derisively referred to as

14586-503: The principles of fluid dynamics and fluid mechanics are widely utilized by other engineering disciplines such as mechanical, aeronautical and even traffic engineers. Related branches include hydrology and rheology while related applications include hydraulic modeling, flood mapping, catchment flood management plans, shoreline management plans, estuarine strategies, coastal protection, and flood alleviation. Earliest uses of hydraulic engineering were to irrigate crops and dates back to

14729-547: The provision of fresh water for agriculture . Run-of-the-river, or ROR, hydroelectricity is considered ideal for streams or rivers that can sustain a minimum flow or those regulated by a lake or reservoir upstream. A small dam is usually built to create a headpond ensuring that there is enough water entering the penstock pipes that lead to the turbines , which are at a lower elevation. Projects with pondage, as opposed to those without pondage, can store water for daily load demands. In general, projects divert some or most of

14872-528: The redevelopment of the dam. Harry Cochrane, Montana Power's chief consulting engineer, supervised the dam's redesign (nearby Cochrane Dam is named after him). On April 1, 1926, the company announced it would spend $ 1 million to build a new powerhouse at Black Eagle Dam. But as work progressed, the engineers realized that the dam and its four powerhouses were too outdated to meet power generation needs. The company adjusted its plans, and planned for an entirely new dam to be built 50 feet (15 m) downstream from

15015-594: The region, making rivers navigable and generally modernizing life in the region. Leonardo da Vinci (1452–1519) performed experiments, investigated and speculated on waves and jets, eddies and streamlining. Isaac Newton (1642–1727) by formulating the laws of motion and his law of viscosity, in addition to developing the calculus, paved the way for many great developments in fluid mechanics. Using Newton's laws of motion, numerous 18th-century mathematicians solved many frictionless (zero-viscosity) flow problems. However, most flows are dominated by viscous effects, so engineers of

15158-422: The removal of the south bank powerhouses. The existing dam was used as a coffer dam while workers poured concrete for the new dam. The new dam was finished on August 1, 1927, and began generating electricity in September. The new dam's reservoir completely drowned the old dam behind it. The new dam was 782 feet (238 m) long and 34.5 feet (10.5 m) high, with a spillway 646 feet (197 m) long. Its height

15301-403: The river bottom was piled near the north bank to create a small island (Tailrace Island), and the powerhouse was built on this manmade shore. The island and the north bank of the Missouri River formed the tailrace (or channel for water leaving the powerhouse) of Black Eagle Dam. Tailrace Island was jointly owned by the power company and the Boston and Montana. A wooden pedestrian bridge was built to

15444-588: The ruling to the Montana Supreme Court in 2007. On December 4, 2007, the Montana Supreme Court unanimously ruled in State Dept. of Revenue v. PPL Montana that the tax appeal board had properly assessed PPL Montana's dams. However, PPL Montana had continued to dispute its tax assessments from 2003 to 2007, and the ruling did not directly address those challenges. But on December 14, 2007, PPL Montana offered to pay its 2003-to-2007 tax assessments at

15587-602: The run of the river flows for generation of power with sufficient pondage for supplying water for meeting diurnal or weekly fluctuations of demand. In such stations, the normal course of the river is not materially altered. Many of the larger run-of-the-river projects have been designed to a scale and generating capacity rivaling some traditional hydroelectric dams. For example, the Beauharnois Hydroelectric Generating Station in Quebec

15730-399: The shanty town can still be seen.) The red sandstone riverbed was leveled as much as possible, and large timbers bolted and cemented (perpendicular to the river's flow) to the rock. Each timber was 8 feet (2.4 m) from the next one downstream, and six cribs were built to form a dam 56.66 feet (17.27 m) deep at its base.The dam's downstream face had a pitch of 1.05:1. From the crest of

15873-482: The slightly lower rate established by the tax appeal board. Another tax issue arose in 2007. The parents of several Montana schoolchildren filed suit in the United States District Court for the District of Montana against PPL Montana. The parents argued that all riverbeds in Montana are owned by the state, are held in trust for the benefit of all the people, and that such riverbeds constitute

16016-522: The slow current, stillness of the water, and low incline of the water from the upriver town of Cascade to Black Eagle Falls (a distance of about 55 miles (89 km) along the winding Missouri River), this body of water has long been known as the "Long Pool." Thomas P. Roberts, who named Black Eagle Falls, gave this body of water its name in 1872. The United States Army Corps of Engineers referred to it by this name beginning at least as early as 1883, and as recently as 1910. The Montana Legislature has used

16159-539: The smelter. On April 7, 1908, construction began on the "Big Stack," a chimney for dispersal of fumes 506 feet (154 m) high, with an interior measurement of 78.5 feet (23.9 m) in diameter at the base and 50 feet (15 m) in diameter at the top. Built by the Alphonse Custodis Construction Co. of New York, it was completed on October 23, 1908, and was the tallest chimney in the world when finished. In 1893–1894, GFWPTC constructed

16302-517: The south bank, and installed two Leffel turbines . The old generators in the first powerhouse were replaced with two new ones capable of generating 1.5 MW each. Two surge chambers were built in the powerhouse as well, and a penstock connected to each chamber. The refurbished south powerhouse now provided power to the smelter, as well as to the flour mill (which had been converted to electricity). In 1909, engineers for Great Falls Power Co. proposed building dams at Rainbow Falls ( Rainbow Dam ) and

16445-507: The state district court ruled in favor of the state (although it denied the state's request for interest on the rent due). PPL Montana appealed to the Montana State Supreme Court. On March 30, 2010, the Montana State Supreme Court held (5-to-2) that the state district court had not erred in its rulings on various issues of summary judgment, that riverbeds were state public trust lands (but not school trust lands) under

16588-593: The state of Montana—with one-third of amount owed payable solely in Cascade County . In February 2005, the Montana State Tax Appeal Board gave the state a partial victory, reducing the state's assessments by 10 percent but otherwise upholding the assessment method. However, the tax board did not address PPL Montana's primary claim that the state was assessing its plants differently solely because they were unregulated. PPL Montana appealed

16731-569: The state that are still operative and in use today. The rulers developed new systems for agriculture and taxation , which continued to be used in parts of the Horn of Africa as late as the 19th century. Further advances in hydraulic engineering occurred in the Muslim world between the 8th and 16th centuries, during what is known as the Islamic Golden Age . Of particular importance was

16874-487: The stockholders in the Great Falls Water Power & Townsite Co. (GFWPTC) was Paris Gibson , a friend of Hill's and the driving force behind the founding of the city of Great Falls. Gibson realized that the Great Falls of the Missouri could provide abundant, cheap electricity for industry, and proceeded to promote the town on this basis. But Gibson's plan meant actually building one or more dams to supply

17017-426: The structure occurred. A fourth major flood hit on June 17, 1997. Heavy, swift snowmelt caused the Missouri River to rise 3 feet (0.91 m) above flood stage. But no damage to the dam was reported. Black Eagle Dam is also equipped with an emergency "trip face" that releases all the flashboards on the dam so that up to 100,000 cubic feet (2,800 m) per second of water can pass over the dam. Black Eagle Dam created

17160-423: The summer of 1887 to determine the suitability of the falls and the best location for a dam. Plans for a dam were drawn up, but no action was taken at that time. Black Eagle Dam was built in order to supply power to a copper smelter . The Boston and Montana Consolidated Copper and Silver Mining Company was organized on July 22, 1887, by the merger of Leonard Lewisohn's Lewisohn Brothers (a copper trading company),

17303-417: The surrounding environment and nearby communities. Run-of-the-river harnesses the natural potential energy of water by eliminating the need to burn coal or natural gas to generate the electricity needed by consumers and industry. Advantages include: Like all hydro-electric power, run-of-the-river harnesses the natural potential energy of water by eliminating the need to burn coal or natural gas to generate

17446-482: The terraces. It is said that if the steps were put end to end, it would encircle half the globe. Eupalinos of Megara was an ancient Greek engineer who built the Tunnel of Eupalinos on Samos in the 6th century BC, an important feat of both civil and hydraulic engineering. The civil engineering aspect of this tunnel was that it was dug from both ends which required the diggers to maintain an accurate path so that

17589-508: The time it reached that city. Two deaths occurred while the dynamiting attempt was made, however: One man drowned while trying to remove flashboards from the dam, and another drowned when his boat capsized. Just two months later, on June 6, Black Eagle Dam suffered damage in yet another flood. Almost 3 inches (7.6 cm) of rain fell in 24 hours, and the Missouri River rose by almost 16 inches (41 cm) in eight hours. The Missouri River rose 8.1 feet (2.5 m) above flood stage (which itself

17732-611: The turbines were cemented into the powerhouse's basement, and each turbine installed in its own pit. Each turbine connected through the first floor roof to an Allis-Chalmers generator rated at 7,000 kVA . DC generators acted as exciters for the Allis-Chalmers generators. Six 6,600/2,200 volt transformers stepped down the power for usage. Black Eagle Dam suffered four major floods after its 1926 reconstruction, but survived them all. The first major flood occurred on June 4, 1953, when early spring rains and sudden snowmelt caused

17875-442: The two are now managed together. The change also instituted a new limit on trout caught and killed below the dam of five fish per day (only one of which could be over 18 inches (46 cm)). Limits on the number of walleye caught per day were lifted in 2010 to protect the rainbow and brown trout populations (they had been five daily and 10 in possession). According to dam officials, there are no screens to prevent fish from going over

18018-593: The two tunnels met and that the entire effort maintained a sufficient slope to allow the water to flow. Hydraulic engineering was highly developed in Europe under the aegis of the Roman Empire where it was especially applied to the construction and maintenance of aqueducts to supply water to and remove sewage from their cities. In addition to supplying the needs of their citizens they used hydraulic mining methods to prospect and extract alluvial gold deposits in

18161-601: The type of weapons which may be used in this area, and where hunters may park. Black Eagle Dam is also utilized as a recreation area. The whitewater just below the falls is a good place for canoeing , inner-tube floating, and kayaking . Hiking and bicycling also occur in the area. Beginning in 2006, the Black Eagle Dam Run (a 5-kilometre (3.1 mi) run/walk and 10-kilometre (6.2 mi) run) has been held at Black Eagle Dam in mid-July. The annual Lewis and Clark Festival, celebrated in late June (the anniversary of

18304-406: The type, the following sections generally refer to Dam-Toe unless otherwise stated. These are listed in order of least impact to most impact, as well as (on average) requisite project size. Dam-toe has no flow regulation and utilizes the natural flow of the river to turn the turbines. Electricity generation is heavily dependent on river flow. Diversion Weir has very little flow regulation, which

18447-450: The upper part of the river does not take place. As a result, people remain living at or near the river and existing habitats are not flooded. Any pre-existing pattern of flooding will continue unaltered, which presents a flood risk to the facility and downstream areas. Due to their low impact, run-of-the-river dams can be implemented in existing irrigation dams with little to no change in the local fluvial ecosystem. Run-of-the-river power

18590-418: The upstream end of the forebay. The main penstock was 400 feet (120 m) long and 9 feet (2.7 m) in diameter, and fed water to the turbines. (Three other penstocks were built but not put into use immediately.) On the north side of the river was another powerhouse (completed in 1892), which contained seven more Victor turbines, capable of generating a total of 1.94 MW of power. Rock and debris carved from

18733-422: Was 15 feet (4.6 m) above the median water level). Five people in the city drowned. The Boston and Montana smelter toppled four fully loaded railroad cars into the Missouri just north of Black Eagle Dam in an attempt to divert the floodwaters from the plant. The worst flood in the city's history at the time, several buildings in town were also washed away. They smashed against Black Eagle Dam, and some went over

18876-451: Was added as an impairing factor in 2000. Sources of these impairments include Black Eagle Dam, upstream abandoned mines, irrigation runoff, industrial sources, and stormwater runoff . The MDEQ has given the area a quality ranking of B-2 (fourth out of 18), declaring it suitable for human consumption and recreation (after treatment) but only marginal for salmonid fish, other aquatic animals, waterfowl and fur-bearing animals. MDEQ has scheduled

19019-419: Was built at a cost of about $ 515,000 (roughly $ 12,335,000 in inflation-adjusted 2010 dollars) on the upstream brink of the falls (to create the deepest reservoir possible). Construction bids were opened on February 5, 1890, with the request for bids specifying that all work must be finished by December 1, 1890. All the bids were rejected, and mechanical engineer Maurice Parker was employed to design and construct

19162-417: Was built next to the south powerhouse and used to provide electricity to clients whenever the main turbines were shut off. A 200-foot-long (61 m) funicular (or inclined railway) provided access to the south powerhouse from the bluff above. A 200-foot-long (61 m), 10-foot-wide (3.0 m) pedestrian suspension bridge ran from the bluffs above each powerhouse over the river. The dam's life expectancy

19305-406: Was built on the south side of the river. It contained three twin, horizontal "Victor" reaction turbines (to which up to six generators could be mounted), each of which generated 1.27 MW of power. The south bank and a masonry wall some distance offshore created a forebay (or short headrace) which fed the iron-enclosed penstocks , and water flow into the penstocks was partially controlled by a gate at

19448-417: Was concrete. The company had planned to build a brick powerhouse. But local bricklayers demanded that they be paid the salary offered by the city rather than the lower rate offered by Montana Power. The company refuse to hire the workers, and built the structure of concrete instead. Concrete and masonry retaining walls north and south of the powerhouse were also built to help prevent erosion of the riverbank into

19591-492: Was created (for a total of eight spillways). Flashboards 1 foot (0.30 m) in height were installed along the entire top of the dam to add water storage capacity. The dam was 15 feet (4.6 m) high and 1,100 feet (340 m) long. The dam began generating electricity in December 1890. Water was permitted to flow over the crest of the dam on January 6, 1891, and the dam was considered complete on March 15, 1891. A two-story brick powerhouse, 40 by 165 feet (12 by 50 m),

19734-401: Was dispatched to the city of Great Falls, warning stations along the way about the dam break. Workers at the Boston and Montana Smelter in Great Falls improvised a wing dam to deflect the floodwaters away from the smelter site and dynamited a portion of Black Eagle Dam to allow the floodwaters to go downstream. Their efforts were not needed, as the Missouri River only rose 7 feet (2.1 m) by

19877-600: Was estimated at 50 years. Ground was broken on the smelter in the spring of 1890. The concentrator opened in March 1891; Brückner cylinders and reverberatory furnaces in April 1892; converters in August 1892; refining furnaces in January 1893; an electrolytic refinery in February 1893; and blast furnaces in April 1893. The cost of the original plant was $ 2 million, and by 1892 more than 1,000 workers were employed at

20020-533: Was highly developed, and engineers constructed massive canals with levees and dams to channel the flow of water for irrigation, as well as locks to allow ships to pass through. Sunshu Ao is considered the first Chinese hydraulic engineer. Another important Hydraulic Engineer in China, Ximen Bao was credited of starting the practice of large scale canal irrigation during the Warring States period (481 BC–221 BC), even today hydraulic engineers remain

20163-423: Was limited by the city's freshwater and sewage facilities, which were just upstream from the dam and would be inundated if the dam were any higher. The dam had an ogee -shaped crest to permit improved water flow over the top. The new dam also had eight floodgates, and a pedestrian walkaway with railing was along the dam's crest to give maintenance workers access to the flashboards and dam. The dam's new powerhouse

20306-450: Was remanded back to the state supreme court for further hearings. Flashboards on the dam were slightly damaged during flooding in the spring and early summer of 2011. Water behind the dam was lowered until it barely crested the dam so repair crews could replace the flashboards. The river above and below Black Eagle Dam is used for fishing. Westslope cutthroat trout were first identified at Black Eagle Falls by Lewis and Clark in 1805, and

20449-480: Was required. By the early 1920s, the needs of the city of Great Falls had outstripped Black Eagle Dam's ability to generate electricity, and the smelter was planning a new electrolytic zinc manufacturing plant that would require 10 MW of power. By 1925, the north powerhouses were seriously outdated. The Montana Power Company began planning for a new dam and powerhouse in late 1925. The Charles T. Main Company oversaw

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