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Historic Properties

National Park Service, National Register of Historic Places

Tour of National Register Historic Places in Seward-->

National Register Historic Places in Seward

  • Jesse Lee Home
  • Ballaine House
  • Lowell Creek Diversion Tunnel
  • St. Peter's Church
  • Seward Depot
  • US Cable Office
  • Swetman House
  • Van Gilder Hotel
  • Brown and Hawkins Store

  • LOWELL CREEK DIVERSION TUNNEL
    Lowell Canyon Rd. & Lowell Point Rd.

    When the Original Townsite of Seward was established in 1903, Lowell Creek ran down what is now Jefferson Street. This is why Jefferson Street is the widest right-of-way in Seward at 100 feet. Lowell Creek is described as a short, flashy creek which rises in the ice fields of the rugged Kenai Mountains. Almost since the beginning of Seward until the Diversion Tunnel was constructed in 1939, Lowell Creek produced from one to three severe floods per year. During those floods large quantities of debris, varying in size from small gravel to huge boulders, were carried down what is now Jefferson Street to the delta from inexhaustible supplies in the surrounding mountain canyons. The deposits amounted to some 27,000 cubic yards annually (roughly 2,700 dump truck loads). On one occasion, in 1935, the stream deposited 10,000 cubic yards in 11 hours (roughly 1,000 dump truck loads).

    These flood deposits on the delta caused periodic changes in the channel through the town as the deposits elevated the areas adjacent to the stream, and property suffered continuing damage. It’s ironic that the same flooding that created the land on which Seward was built, later threatened the location and integrity of the original townsite.

    In 1927 the Alaska Railroad Commission provided a small diversion dam and a large timber flume to carry debris down Jefferson Street and deposit it into Resurrection Bay. This flume, in spite of heavy maintenance repairs, had so deteriorated by 1937 that it was beyond economical repair and constituted a menace to the community. It was evident that a better designed, relocated flood control project was necessary.

    The Flood Control Project on Lowell Creek, or the Lowell Creek Diversion Tunnel as it is generally known today, was constructed to replace the 1927 flume. This historic flood control project was the U.S. Corp of Engineers first completed flood control project in Alaska, and it represents exemplary engineering for the time and place. Construction began in August 1939 and the project was complete in November 1940.

    The Project consists of three parts:
    1. The Diversion Dam;
    2. The Tunnel; and
    3. The Outlet.

    The Diversion Dam is 400 feet long with a maximum height of 25 feet. The Tunnel which runs through Bear Mountain, is 10 feet in diameter and 2,068 feet long. It is lined with concrete, and the floor is armored with 40 pound railroad rails. The outlet of the tunnel is located at the toe of Bear Mountain. It is an open concrete flume 10 feet wide and about 109 feet long which, as we will see, discharges into Resurrection Bay.

    Since construction of the diversion tunnel was completed in 1940, the project has effectively controlled Lowell Creek and its regular flooding. Despite severe damage to Seward in the 1964 earthquake, the flood control project withstood the massive earthshocks. Two years after the earthquake, in 1966, during one of the heaviest run-offs of record, Lowell Creek rose to within two feet of the crest of the dam. In the recent flood events of 1986 and 1995 the creek has been within inches from the top of the dam.

    Today, debris continues to be deposited at the outfall where it naturally flushes out into the Bay. Except when there is a flood event, the gravel, rock and other debris comes in such quantities that the water can’t wash out the debris fast enough and it builds up. It is during those times that the City works on the east side (Bay side) of the bridge and pushes the built up rock towards the bay.

    The 60 year old tunnel, which has been owned by the City of Seward since shortly after its construction, is in need of significant repairs. The Corp of Engineers will be repairing the tunnel this year.

    Because of the amount and size of debris that flows down Lowell Creek during flood events there is a justified concern that debris could block the tunnel and cause it to fail. In order to prepare for such an event the City is pursuing a long term solution. Two different options have been identified - construction of a second tunnel through Bear Mountain which would be 10 feet wider than the current tunnel and cost approximately 30 million dollars. A second option is construction of a aquaduct under Jefferson Street.


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