The Knik River / k ˈ n ɪ k / ( Dena'ina : Skitnu ; Ahtna : Scitna’ ) is a 25-mile-long (40 km) river in the U.S. state of Alaska . Its source is at Knik Glacier , from which it flows northwest and west and empties into the head of Cook Inlet's Knik Arm , near the mouth of the Matanuska River . It is bridged twice (old and new bridges) where the Old Glenn Highway crosses it near the Butte, and also bridged on the Hayflats.
16-462: It is characterized by a broad flat plain with a bed of finely ground gravel and sand and silt. During windstorms, large quantities of fine material is blown from the riverbed and deposited in locations generally downstream or west. The river itself is relatively shallow and wide and considered a class I float. It drops about 400 feet (120 m) from the glacier to the salt water, or roughly 16 feet (4.9 m) per mile. The 4 miles (6.4 km) above
32-568: A surge tank . They can be a combination of many components such as anchor block, drain valve, air bleed valve, and support piers depending on the application. Flow is regulated to suit turbine operation and is cut off when turbines are not in service. Penstocks, particularly where used in polluted water systems, need to be maintained by hot water washing, manual cleaning, antifouling coatings, allowing waters to go anoxic , and desiccation used to dry fouling out so that it may slough off or become easier to remove through manual processes. The term
48-401: A means of isolation of flows and regulate the flow of water while delivering it to waste management facilities or power plants. Penstocks are incorporated into the surface water management systems (drainage) of many landfill sites. Retention basins are constructed in order to store storm water, limiting the discharge from the site to its pre-development rate. Valved penstocks are installed at
64-725: A natural landslide dam in the Eklutna Valley. It regulated the river to the Lower Eklutna Dam which diverted water into the Old Eklutna Power Plant . The lake dam was rebuilt and improved in 1941 after the previous structure failed. During this same year, the population in Anchorage increased greatly with the onset of World War II . To cope with increasing power demand, the United States Bureau of Reclamation proposed
80-456: Is 26 ft (7.9 m) tall and 555 ft (169 m) long. It is filled with 5,000 cu yd (3,800 m ) sand, gravel and earth and its crest is 875 ft (267 m) above sea level. The reservoir created by the dam, Eklutna Lake, covers 3,247 acres (1,314 ha) and is 7 mi (11 km) long. At an elevation of 867.5 ft (264.4 m), the reservoir holds 182,000 acre⋅ft (224,000,000 m ) of water. To connect
96-410: Is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is of Scots origin, and was inherited from the earlier technology of mill ponds and watermills , with penstocks diverting pond waters to drive the mills. Penstocks for hydroelectric installations are normally equipped with a gate system and
112-419: Is also used in irrigation dams to refer to the channels leading to and from high-pressure sluice gates . Penstocks are also used in mine tailings dam construction. The penstock is usually situated fairly close to the center of the tailings dam and built up using penstock rings, short reinforced ring-like sections of pipe which nest one within the other when stacked and thereby control the water level, letting
128-539: The slimes settle out of the water. This water is then piped under the tailings dam back to the plant via a penstock pipeline. Inlet valves on the downstream end of penstocks are often used at mill sites to control the flow of water through the mill wheel, or to pen water into a mill pool. Similar structures which are not enclosed are head races or leats (non elevated), and flumes (elevated). Penstocks are commonly used in water management systems such as surface water drainage and foul water sewers. Penstocks provide
144-525: The Eklutna Project. It included raising the dam and installing a new power plant opposite Goat Mountain to the north, along the Knik River . The United States Congress authorized the project on 31 July 1950. Construction began in 1951 and raising the dam commenced the following year. The first generator was commissioned on 8 January 1955, the second and last on 1 April 1955. On 1 July 1955 the entire project
160-636: The communities of Knik-Fairview and Knik River , derives from the Inupiaq word igniq ("fire"). The Denaina term for the Knik river was "Skitnu", (meaning Brush River). The river runs near the border between the Matanuska-Susitna Borough and the Municipality of Anchorage . Much of its length is paralleled by the paved Old Glenn Highway and the paved (as of 2000) Knik River Road, along which can be found
176-572: The community of Knik River . 61°28′15″N 149°24′23″W / 61.47083°N 149.40639°W / 61.47083; -149.40639 Eklutna Dam The Eklutna Dam , also referred to as the New Eklutna Dam or Upper Eklutna Dam , is an embankment dam on the Eklutna River about 30 mi (48 km) northeast of Anchorage in Alaska , United States . The primary purpose of
SECTION 10
#1732847620874192-496: The dam is hydroelectric power generation and it supports a 47 MW power plant. It was first completed in 1929 but was rehabilitated or rebuilt on several occasions over its history. Ownership of the dam and power plant is shared by Chugach Electric and Matanuska Electric. The original dams and power plant was the idea of businessman Frank Reed. It was constructed by the Anchorage Light and Power Company between 1927 and 1929 atop
208-461: The hayflats bridge is unusual in that it remains unfrozen most winters because the Eklutna project discharges warmer water into the tailrace. Discharge normally is about 5000 to 6000 ft3/s in the summer (140 to 170 m3/s), with floods of 60,000 ft3/s (1700 m3/s) or more not uncommon. The term "knik," present in the names of the river, the arm of Cook Inlet, and the glacier, as well as
224-486: The reservoir and power plant, there is a 9 ft (2.7 m) diameter, 4.46 mi (7.18 km) long penstock which starts at the intake, located on the northwest corner of the lake. From the intake, water rushes down the penstock where it reaches two 23.5 MW Francis turbine -generators. Water used by the power plant is then discharged into the Knik River. Download coordinates as: Penstock A penstock
240-508: Was complete. The Great Alaska earthquake in March 1964 caused significant damage to the dam, particularly the water intake for the power plant. The intake shifted towards the lake and frozen alluvium beneath and near the dam's spillway densified , creating voids. Later, in July of the same year, as the ground thawed, two cracks formed near the spillway and portions of the dam filled the void. The dam
256-475: Was deemed unsafe and a taller embankment dam was constructed just downstream. Construction and rehabilitation was carried out until 1966. In 1997 the Alaska Power Authority sold the dam and power plant to Anchorage Municipal Light and Power, Chugach Electric Association and Matanuska Electric Association for US$ 6 million. Chugach Electric acquired Anchorage Municipal Light and Power in 2020. The dam
#873126