Dungeness Fish Hatchery

Dungeness Fish Hatchery

Background:

The Dungeness Fish Hatchery, located just off the Dungeness River in Sequim, Washington, is a Chinook and Coho Salmon rearing facility. In 2020, the facility undertook a major upgrade to their intake structure and distribution building. The upgraded intake structure uses an off-channel diversion with ISI wedge wire T screens and a fish bypass to source water to the hatchery and meet current federal and state fish screen criteria for anadromous salmonids.

The intake upgrade included installation of four ISI T30‐42HA-R hydraulic drive brush cleaned screen units where each T screen has two cylinders, each measuring 30 inches (762 mm) in diameter and 42 inches (1,067 mm) in length. With a 1.75-mm slot size and 50 percent open area, the screens provide the maximum diversion rate of 80 cfs (51.7 MGD, 8,155 m³/h) at an approach velocity of 0.4 fps (12.2 cm/s) with a 9.5 percent screen surface area redundancy. The screen system includes a vertical retrieval tracks with knife gates.

The system includes additional custom features which are tailored to the owner preference and site conditions: 1) the screen local controls include a corded pendent which allows the operator to move around the intake deck and observe the screens while they are being raised or lowered; 2) a water level differential system triggers an automatic cleaning cycle when a threshold differential is reached, and; 3) a water jetting system, which was designed and fabricated by others, was included in the design to sluice sediment from the off-channel diversion back to the river.

Benefit of ISI System

ISI's retrievable brush-cleaned cylindrical screen system provides the following key advantages at this site:

1. The brush cleaning system ensures that the screen surface will remain free of debris and fouling organisms and therefore maintain compliance with approach velocity requirements and reliably sources water to the facility;
2. The retrievable screen with knife gate design allows the screens to be raised out of the river for inspection and maintenance while keeping the intake to the hatchery closed;
3. The wired pendant allows the operators to move around the intake deck and observe the screens while they are being raised or lowered;
4. A water level differential monitoring system is tied into the screen controls so that automatic cleaning will occur should a differential threshold be reached.

Owner:

Washington Department of Fish & Wildlife

Engineer(s):

HDR

General Contractor:

Interwest Construction, Inc.

Location:

Dungeness River, Sequim, WA