Lowell Creek Diversion Tunnel
Encyclopedia
The Lowell Creek Diversion Tunnel is a flood control
project located near Seward
, Alaska
, United States
. The project was constructed to alleviate flooding of Lowell Creek in Seward. It was the Army Corps of Engineers' first flood control project in Alaska.
Originally, Lowell Creek ran through Seward along what is now Jefferson Street. Beginning with the town's establishment in 1903, the fast-moving stream produced one to three severe floods a year until the tunnel was built in 1939. The floods carried large amounts of debris from the mountains, including 11,000 cubic yards in an 11 hour period in 1935.
In 1927 the Alaska Railroad
constructed a small diversion dam and flume to carry debris down Jefferson Street to drainage in Resurrection Bay
. However, conditions were deteriorated beyond repair by 1937.
The Army Corps of Engineers began construction of the new project in August 1939. The project consisted of: a diversion dam
of 400 feet (121.9 m) long and up to 25 feet (7.6 m) high that diverted the creek off its original path; a 2068 feet (630.3 m) long, 10 feet (3 m) wide tunnel through Bear Mountain; and the 109 feet (33.2 m) long, 10 feet (3 m) outlet flume which drains into the bay. The new control has withstood the 1964 Alaska earthquake, as well as severe flooding in 1966, 1986, and 1995, which has brought the water level within feet of cresting
the dam.
Though the project has prevented significant flooding events, debris builds up at the output and the city must work to move the debris towards the bay. With the risk that debris build up during a flooding event, new projects are being considered to replace the Diversion Tunnel, including a new, wider tunnel through Bear Mountain at a cost of $
30 million, or an aqueduct
underneath Jefferson Street.
Flood control
In communications, flood control is a feature of many communication protocols designed to prevent overwhelming of a destination receiver. Such controls can be implemented either in software or in hardware, and will often request that the message be resent after the receiver has finished...
project located near Seward
Seward, Alaska
Seward is a city in Kenai Peninsula Borough in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 3,016....
, Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The project was constructed to alleviate flooding of Lowell Creek in Seward. It was the Army Corps of Engineers' first flood control project in Alaska.
Originally, Lowell Creek ran through Seward along what is now Jefferson Street. Beginning with the town's establishment in 1903, the fast-moving stream produced one to three severe floods a year until the tunnel was built in 1939. The floods carried large amounts of debris from the mountains, including 11,000 cubic yards in an 11 hour period in 1935.
In 1927 the Alaska Railroad
Alaska Railroad
The Alaska Railroad is a Class II railroad which extends from Seward and Whittier, in the south of the state of Alaska, in the United States, to Fairbanks , and beyond to Eielson Air Force Base and Fort Wainwright in the interior of that state...
constructed a small diversion dam and flume to carry debris down Jefferson Street to drainage in Resurrection Bay
Resurrection Bay
Resurrection Bay is a bay on the Kenai Peninsula of Alaska, United States. Its main settlement is Seward, located at the head of the bay. It received its name from Alexandr Baranov, who was forced to retreat into the bay during a bad storm in the Gulf of Alaska...
. However, conditions were deteriorated beyond repair by 1937.
The Army Corps of Engineers began construction of the new project in August 1939. The project consisted of: a diversion dam
Diversion dam
A diversion dam is the term for 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...
of 400 feet (121.9 m) long and up to 25 feet (7.6 m) high that diverted the creek off its original path; a 2068 feet (630.3 m) long, 10 feet (3 m) wide tunnel through Bear Mountain; and the 109 feet (33.2 m) long, 10 feet (3 m) outlet flume which drains into the bay. The new control has withstood the 1964 Alaska earthquake, as well as severe flooding in 1966, 1986, and 1995, which has brought the water level within feet of cresting
Crest (hydrology)
In hydrology, crest is the highest level above a certain point that a river will reach in a certain amount of time. This term is usually limited to a flooding event and from ground level ....
the dam.
Though the project has prevented significant flooding events, debris builds up at the output and the city must work to move the debris towards the bay. With the risk that debris build up during a flooding event, new projects are being considered to replace the Diversion Tunnel, including a new, wider tunnel through Bear Mountain at a cost of $
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
30 million, or an aqueduct
Aqueduct
An aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....
underneath Jefferson Street.