A diversion dam is a dam that diverts all or a portion of the flow of a river from its natural course. Diversion dams do not generally impound water in a reservoir ; instead, the water is diverted into an artificial water course or canal , which may be used for irrigation or return to the river after passing through hydroelectric generators , flow into a different river or be itself dammed forming an onground or groundwater reservoir or a storm drain .
19-953: Poe Dam is a concrete gravity diversion dam on the North Fork Feather River , about 5 miles (8.0 km) north of Lake Oroville in Butte County , California in the United States . Completed in 1959, the dam is the lowermost component of the Pacific Gas and Electric Company 's Feather River Canyon Power Project, a system of 10 hydroelectric stations along the North Fork. The dam is 60 ft (18 m) high and 440 ft (130 m) long, with water flows controlled by four 50 ft × 41 ft (15 m × 12 m) radial gates . The dam diverts water through an 6.3-mile (10.1 km) tunnel to
38-474: A gravity dam is built to support the weight of the dam and all the water, it is quite flexible in that it absorbs a large amount of energy and sends it into the Earth's crust. It needs to be able to absorb the energy from an earthquake because, if the dam were to break, it would send a mass amount of water rushing downstream and destroy everything in its way. Earthquakes are the biggest danger to gravity dams and that
57-432: A problem, as they can scour dam foundations. A disadvantage of gravity dams is that their large concrete structures are susceptible to destabilising uplift pressures relative to the surrounding soil. Uplift pressures can be reduced by internal and foundation drainage systems. During construction, the exothermic curing of concrete can generate large amounts of heat. The poorly-conductive concrete then traps this heat in
76-399: Is lower than the other types of dams. Buttress style diversion dams are designed using angle supports on the downstream side of the dam. The supports are fixed to the wall of the dam in order to help counteract the force of the water on the dam. Buttress style dams are built across wide valleys that do not have a solid bedrock foundation. Bedrock is solid rock that makes up the upper part of
95-461: The 120 megawatt Poe Powerhouse, located on the upper reaches of Lake Oroville. The powerhouse has a rated hydraulic head of 477 ft (145 m), generating about 500 million kilowatt hours annually. On November 8, 2018, the Camp Fire , a destructive wildfire that destroyed the nearby community of Concow and the town of Paradise and caused multiple deaths, originated close to Poe Dam at
114-399: The Earth's crust. Bedrock can be made from sedimentary, igneous, and metaphoric rock origins. Buttress dams require extensive steel framework and labor. As a result, buttress style dams are expensive to construct and are seldom built today. Arch style diversion dams are designed using an arch shape with the top of the arch facing upstream. The arch shape provides extra strength to counteract
133-442: The dam primarily arises from the range of normal force angles viably generated by the foundation. Also, the stiff nature of a gravity dam structure endures differential foundation settlement poorly, as it can crack the dam structure. The main advantage to gravity dams over embankments is the scour -resistance of concrete, which protects against damage from minor over-topping flows. Unexpected large over-topping flows are still
152-406: The dam structure for decades, expanding the plastic concrete and leaving it susceptible to cracking while cooling. It is the designer's task to ensure this does not occur. Gravity dams are built by first cutting away a large part of the land in one section of a river, allowing water to fill the space and be stored. Once the land has been cut away, the soil has to be tested to make sure it can support
171-418: The diversion dam to the reservoirs can be used for industrial applications or for municipal water supply. The design a diversion dam will fall into one of four basic types: embankment style dams, buttress style dams, arch style dams, and gravity style dams. Embankment style diversion dams are constructed to counteract the force of the water pushing on the dam by building a dam with enough weight to withstand
190-598: The flow of water under the dam. If water were to get under the dam, the dam could fail. Gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil. Stability of
209-498: The flow rate of the runoff into channels downstream. Diversion dams are used to raise the water level in order to redirect the water to the designated location. The diverted water can be used for supplying irrigation systems or reservoirs . Diversion dams are installed to raise the water level of a body of water to allow the water to be redirected. The redirected water can be used to supply irrigation systems, reservoirs, or hydroelectric power generation facilities. The water diverted by
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#1732783473740228-403: The force of the water. Arch style dams are generally constructed in narrow canyons. Arch style dams are commonly made from concrete. To ensure the dam's integrity, a solid contact between the bedrock foundation and the dam's concrete base is required. The dome style dam is a type of arch dam. The dome style dam curves in both the horizontal plane and vertical plane. The arch style dam only curves in
247-434: The force. Embankment dams are commonly made from materials in the surrounding area where the dam is being built. The materials generally include: sand, gravel, and rocks. The combination of these building materials with either clay or an impervious membrane gives the embankment dam its integrity. As a result, the combination of its simple construction and locally available building materials the cost of building an embankment dam
266-468: The foundation's support strength: the Westergaard, Eulerian, and Lagrangian approaches. Once the foundation is suitable to build on, construction of the dam can begin. Usually gravity dams are built out of a strong material such as concrete or stone blocks, and are built into a triangular shape to provide the most support. The most common classification of gravity dams is by the materials composing
285-453: The horizontal. Gravity style diversion dams are built to counteract the force of the water pushing on the dam by building a dam with enough weight to withstand the force. Gravity dams are commonly constructed using masonry or cement. The foundations of the gravity dams are generally constructed on top of a solid bedrock foundation. However, gravity dams can be built over unconsolidated ground as long as proper measures are put in place to stop
304-587: The location of downed power lines across the Feather River. In an initial comment, PG&E stated that a cause of the fire had not been determined yet and that there would be an investigation. Poe Dam is a popular kayaking site. Diversion dam An early diversion dam is the Ancient Egyptian Sadd el-Kafara Dam at Wadi Al-Garawi, which was located about twenty five kilometres south of Cairo . Built around 2600 BC for flood control,
323-566: The structure was 102 metres long at its base and 87 metres wide. It was destroyed by a flood while it was still under construction. Diversion dams are one of three classifications of dams which include: storage dams, detention dams , and diversion dams. Storage dams are used to store water for extended lengths of time. The stored water then can be used for irrigation , livestock , municipal water supply, recreation, and hydroelectric power generation. Detention dams are built to catch surface runoff to prevent floods and trap sediment by regulating
342-408: The structure: Composite dams are a combination of concrete and embankment dams . Construction materials of composite dams are the same used for concrete and embankment dams. Gravity dams can be classified by plan (shape): Gravity dams can be classified with respect to their structural height: Gravity dams are built to withstand some of the strongest earthquakes . Even though the foundation of
361-407: The weight of the dam and the water. It is important to make sure the soil will not erode over time, which would allow the water to cut a way around or under the dam. Sometimes the soil is sufficient to achieve these goals; however, other times it requires conditioning by adding support rocks which will bolster the weight of the dam and water. There are three different tests that can be done to determine
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