Salmon River Pump Station Upgrades

Overview 

The Township of Langley wants your feedback on proposed improvements at the Salmon River pump station. Thank you for completing the online survey to provide your feedback. 

The Salmon River Pump Station upgrades are intended to provide the community with reliable year-round fish-friendly pumping and flood protection during freshet and severe rainfall events. The project focuses on two pump upgrades: 

When the Fraser River water levels rise, the Salmon River Pump Station flood box outlet gates close to avoid upstream flooding. Once closed the Salmon River can no longer flow naturally downstream. During these events, the Salmon River pump station is activated to maintain natural flow patterns from the Salmon River to the Fraser River.

Currently, the Salmon River pump station is equipped with one fish-friendly screw pump and three non-fish friendly axial pumps. The three non-fish friendly axial pumps are limited to operate during freshet only (May to August), so during abnormal weather events outside of freshet these pumps are not allowed to operate. The addition of a new fish-friendly axial, and a new fish friendly screw pump to the Salmon River Pump Station would offer immediate benefits to the Fort Langley community and aquatic ecosystem including:

• improve year-round flood protection
• increase fish-friendly pumping capacity
• support healthier fish populations and local aquatic ecosystems
• help protect spawning, rearing, and overwintering habitats

When Fraser River levels are high, the Salmon River Pump Station acts as a backup system to the gravity draining flood boxes to help limit upstream flood extents, minimizing the risk of fish stranding during severe rainfall events and the Fraser River tidal cycle.

Background 

The Salmon River watershed, encompassing approximately 77 km², drains from Abbotsford through the Township of Langley and discharges into the Fraser River's Bedford Channel via the Salmon River Pump Station outlet flood boxes. The Salmon River provides critical spawning, rearing, and overwintering habitats for numerous fish species, and supports diverse terrestrial wildlife and a variety of land uses, including agricultural activities, and residential areas, each with distinct drainage and flood management needs. 

The original Salmon River Pump Station was constructed by the Township in 1949. The pump station included three non-fish friendly axial pumps and four outlet flood boxes to help mitigate flooding of Fort Langley’s agricultural lands during freshet and other abnormal high-flow periods. The pump station operated in that arrangement for approximately 45 years until one of the non-fish friendly axial pumps was replaced with a larger capacity non-fish friendly axial pump in 1984. 

In 1997 a new pump station was built adjacent to the 1949 pump station which included two new outlet flood box channels and one fish-friendly screw pump. The 1997 station upgrade also included an allowance for a second fish-friendly screw pump to be installed in the future. The Salmon River pump station site layout is shown below.

Proposed Salmon River Pump Station upgrades 

Despite the pump station upgrade in 1997, there continues to be a number of challenges related to pumping, flooding, and water levels within the Salmon River system. The fish-friendly screw pump operates year-round; however, use of the three non-fish friendly axial pumps is currently limited by operational restrictions imposed by Fisheries and Oceans Canada, which allows their operation during freshet only.  

The below figure shows current pump use with flow data for a typical year on the Fraser River and Salmon River, highlighting peak Fraser River flow in June and peak Salmon River flow around November. 

The proposed design prioritizes two pump upgrades aimed at enhancing fish-friendly pumping capacity in order to provide reliable, year-round flood protection for the Fort Langley community: 

1. Installing a second fish-friendly screw pump in the empty pump bay as previous planned for, and
2. Replacing the 1984 non-fish friendly axial pump with a fish-friendly axial pump.

Screw pump upgrade – The existing fish-friendly screw pump station constructed in 1997 moves water using a large, rotating screw, which creates flow conditions that allow fish passage to the Fraser River. The new fish-friendly screw pump will be installed in the empty bay and will provide an additional 2,000 litres/second of fish-friendly pump capacity which doubles the capacity of the screw pump station facility to 4,000 litres/second.  

Axial pump upgrade – The existing axial pump station constructed in 1949 consists of three non-fish friendly axial pumps which combine for a pumping capacity of approximately 4,000 litres/second. As these pumps are not fish-friendly, their use is limited by operational restrictions which allow them to be used during freshet only. Replacing the 1984 non-fish friendly axial pump with a new fish-friendly axial pump will provide an additional 1,500 litres/second of fish-friendly pumping capacity. 

As part of the upgrades, an application for amendment to the existing pump station operation guidelines will be submitted to Fisheries and Oceans Canada to authorize year-round pumping for the two new fish-friendly axial and screw pumps, while maintaining the existing operating conditions for the 1949 non-fish friendly axial pumps.