The Lake Washington Ship Canal and the Mills of Salmon Bay
With federal funds approved for the canal and locks, the City of Seattle worked towards preparing roads and bridges to handle increased traffic, both on land and on the water. Bridges would also have to accommodate the larger boats that could now make passage through the waterway. Voter-approved bonds funded construction of two bridges: the Ballard Bridge opened in 1916 and the Fremont Bridge in June 1917, three weeks before the formal dedication of the Lake Washington Ship Canal.
Top left: Ballard Bridge opening for tall ship, 1918. Right: Men in north trunk sewer siphon tunnel, 1913. Items 130310 and 6229, Series 2613-07, Engineering Department Photographic Negatives, Seattle Municipal Archives.
Water and Sewer
The City also needed to improve water and sewer service north of the canal. In 1913 funds were appropriated for a tunnel to carry water from the Capitol Hill reservoir across the east end of Lake Union. Two shafts 65 feet deep and 16 feet in diameter made of reinforced concrete contained a concrete tunnel 12 feet in diameter and 916 feet long. Steel water mains replaced the wood stave pipes previously carried on the Latona Bridge. The engineers predicted "this structure will... probably be ample for the needs of the section lying north of the Lake Washington Canal for all time."
To manage sewage, the North Trunk Sewer was completed in 1918. Twelve feet in diameter, it carried wastewater under the canal and Fort Lawton and discharged into Puget Sound.
Raising Ballard’s Streets
Above: Shilshole regrade pumping map (detail) showing area around Shilshole Avenue to be regraded. Seattle Municipal Archives. Below right: regrading Shilshole Avenue to raise street above new water level (Pheonix Mill in view), 1914. Bottom two photos: bulkhead near 11th Ave. NW, showing pool of water on top of hydraulic fill, extended to within 12 feet of the bulkhead (pictured: civil engineer Carl H. Reeves), 1915. Items 51958, 51956, and 51953, Series 2613-07, Engineering Department Photographic Negatives, Seattle Municipal Archives.
Street grades along Shilshole Avenue had to be raised to be even with the new water level of Salmon Bay. City Engineer A.H. Dimock initially proposed to use the waste material from the canal dredging to fill in the mill properties and bring them to elevation. However, this approach was determined to be impractical from both a technical and a legal standpoint. In 1912, the City created a special taxing district (a Local Improvement District) to raise Ballard streets and to repave, replank, and make other improvements such as new sewers, walkways, water service, and fire protection. Owners of the Bolcom, Stimson, and Cedar Lumber mills were permitted to build a temporary bulkhead to protect their property during the regrading.