Little Boston Chum Hatchery Intake System
The Port Gamble S’Klallam Tribe operates the small Chum Salmon hatchery at the mouth of a small stream draining into Port Gamble Bay at the north end of Hood Canal. The Tribe sought a firm to provide planning and design services for improvements to the Little Boston Chum Hatchery water supply system. The project goals included improving the capacity of the supply system, reducing silt in the water to avoid mortality in the incubation and rearing facilities, providing a sluice gate to manage sediment at the intake, and improving access and debris management at the intake.
Kleinschmidt’s design approach was based on our understanding of the project goals, site conditions, and evaluations of the water supply piping headloss, retention pond settling performance, and a site survey conducted by Kleinschmidt. We prepared a design that upgraded the inlet structure at the dam with a new trash rack, improved access, provided a new inclined screen, and included a 30-inch diameter sluice gate. The design flow for the hatchery is 1 cfs. The existing 6-inch PVC pipeline was replaced with a 10-inch HDPE pipeline to decrease headloss, and a 20-micron drum filter was added to manage turbidity. An aeration tower was included for the incubation supply to ensure optimal dissolves gas conditions in the water supplied to the eggs.
Kleinschmidt prepared construction bid documents consisting of drawings with integrated specifications and a construction cost opinion for the proposed improvements. The initial design was completed in 2019, however, the Tribe received additional funding in 2020 to upgrade their office storage building into an expanded two-story building. This development adjusted their goals to locate the filter within this building for improved access and the necessary design modifications were made in 2021 and for the construction schedule for 2022.
Kleinschmidt’s design improved the supply capacity, enhanced water quality, improved debris management, and efficiently incorporated the filter into the upgraded office storage building.