Chittenden Locks fish ladder to close May 13-23

Published May 9, 2013
SEATTLE – The fish ladder at the Hiram M. Chittenden Locks in Ballard will close for annual maintenance May 13-23.

Most of the fish ladder plaza, ramp and viewing room will close during maintenance. It will not affect pedestrian and bicycle commuter traffic or locking operations.

The U.S. Army Corps of Engineers operates the Locks and every spring Seattle District employees perform the maintenance prior to the adult salmon upstream spawning migration.

Thousands of salmon annually traverse the fish ladder, safely migrating into Lakes Union and Washington’s fresh waters. Last year nearly 145,000 Sockeye and more than 15,100 Chinook and 27,500 Coho were counted at the Locks during migration by a Muckleshoot Indian Tribe and Washington State Department of Fish and Wildlife cooperative.

The fish ladder instrumentation and sensors run non-stop and the maintenance period allows for cleaning, inspections and any repairs necessary to prevent a possible disruption during migration. A computerized control system monitors several key parameters, including salinity and water flow, adjusting valve gates and weirs for optimal conditions. Locks Maintenance Superintendent Paul Francois said it’s critical to ensure the systems are running to specified parameters.

The ladder was one of the first in the nation. During planning of the locks in the early 1900s, then Seattle District Engineer Maj. Hiram M. Chittenden understood the importance of salmon to the Pacific Northwest’s ecosystem and incorporated a 10-weir ladder. In 1976, Corps officials renovated and improved the ladder to reflect changes in fish conservation. The Locks continue to be a focus of studies detailing migrating juvenile and adult salmon behavior.

A cooperative effort among the Corps, U.S. Fish and Wildlife Service, WDFW, Muckleshoot Tribe, City of Seattle, King County and Water Resource Inventory Area 8 has resulted in many fish passage improvements.

For more information about activities at the Locks, visit the Locks’ Web site at Also follow the Locks on Facebook and Twitter: and
Bill Dowell

Release no. 13-021