SC 25 - Water velocity in the culvert was 1.17 m/s. This would be a barrier to juvenile rainbow trout. The pool depth and outfall drop, 63 cm and 61 cm respectively, also created a barrier for juvenile, and possibly adult rainbow trout. At this site, a juvenile bull trout was found downstream of the culvert and no fish were caught upstream of the culvert. This may indicate the culvert is also a barrier to juvenile bull trout.

This culvert may require replacement with an open bottom arch or open bottom box culvert of appropriate size to reduce the water velocity and eliminate the barrier posed by the outfall drop. These changes could result in a gain of 3.85 km of high quality habitat.

SC 35 – Water velocity in the culvert was 1.4 m/s. This velocity is a barrier to most juvenile fish. In addition, the outfall drop was 115 cm. While the maximum jump heights of adult fish exceed this height, there is insufficient pool depth downstream of the culvert. The water exiting the culvert falls on boulders, and the pool just downstream of these boulders is only 110 cm deep, resulting in a pool depth to outfall drop ratio of less than 1.25. Therefore, this culvert is likely a barrier to all fish.

At this site, a juvenile bull trout was found downstream of the culvert and no fish were caught upstream of the culvert. This may also be an indication that the culvert is a barrier.

Modification of this culvert could include reducing culvert slope to that of the channel, installing baffles to lower water velocity, installing steps to backwater the culvert outlet, and increasing the depth of the pool. The boulders immediately downstream of the outfall should be removed. These modifications could result in a gain of approximately 50 m of high quality habitat between the culvert and an upstream waterfall. The upstream waterfall is approximately 9 m in height and is a barrier to all fish.

SC 22 - Water velocity in the culvert was 0.78 m/s, and would be a barrier to juvenile rainbow trout. The outfall drop is 19 cm, and the water exiting the culvert falls on boulders. Although the pool just downstream of these boulders was 28 cm deep, this culvert is likely a barrier to all fish. No fish were caught above or below this culvert. It is possible a beaver dam downstream prevents the passage of fish upstream to this culvert.

Access to 600 m of stream habitat leading up to a lake, as well as the lake itself could be gained by modifying the culvert. Modifications could include installing baffles to reduce velocity, reducing the present culvert slope (6.4 %) to that of the stream below the culvert (1.5 %), and backwatering the outflow. However, further assessment is required to determine if a beaver dams located 7 m upstream and 25 m downstream prevents the movement of fish.

SC 40 – This culvert was not found to be a barrier to fish. Water velocity in the culvert was low (0.22 m/s), there was no outfall drop, and the culvert was clear of debris. Rainbow trout were caught above and below the culvert.

SC 50 - Pool depth (83 cm) was sufficient and outfall drop was low enough (15 cm) for all species to jump into the culvert. Culvert and stream gradients were low (2.8 % and 1.25 % respectively). However, water velocity in the culvert was 1.5 m/s. This velocity is likely a barrier some adult rainbow trout and all juvenile rainbow trout. Therefore, we considered the culvert to be a partial barrier.

Juvenile rainbow trout were found above and below the culvert. Fish caught upstream of the culvert could be the offspring of adults that were able to pass through the culvert.

This culvert should be replaced with an open bottom arch or open bottom box culvert of the appropriate size. This would decrease the culvert gradient to that of the stream and would reduce water velocity. This would allow juvenile fish to access 1.7 km of high quality stream habitat between the culvert and an upstream high gradient section of the creek.

SC 49 – The depth of the pool at the outlet was 19 cm and was not sufficient to allow fish of any lifestage to jump the 25 cm into the culvert. The water velocity in the culvert was 1.15 m/s which also acts as a barrier to juvenile rainbow trout. Therefore, this culvert was considered a full barrier.

No fish were caught upstream or downstream of this culvert. As there are several beaver dams downstream of this culvert, it is possible fish access to the culvert is limited.

Backwatering the culvert could be used to increasing the pool depth to a minimum of 30 cm. In addition, installing baffles or boulders in the culvert could reduce water velocity. These modifications would allow fish access to an additional 5.35 km of stream. However, fish access past several beaver dams approximately 20 m downstream of the culvert should be assessed.

SC 58 – Currently, this culvert is partially blocked by debris, and is likely a barrier to fish passage. There were no other features that suggested this culvert is a barrier when clear. The water velocity in the culvert was low (0.17 m/sec), the outfall drop was small (0.15 m) and the outfall pool was relatively deep (0.39 m). However, as stream and culvert gradients were 5 % and 4.7% respectively, velocity may a barrier during higher flows. We recommend re-assessment once maintenance and repairs have been completed.

No fish were caught above or below this culvert. This is likely due to the presence of a full barrier culvert (SC 49) downstream of SC 58.

Repairing and cleaning this culvert could allow fish access to an additional 1.35 km of habitat.

SC 16 – The water velocity in the culvert was 1.05 m/s, which is a barrier to juvenile fish. Also, the outfall drop was relatively large (60 cm) and the pool below the culvert was only 30 cm deep. This would be a barrier to most fish. The culvert gradient (7.9 %) was greater than the channel gradient (4 %), and may contribute to passage problems by increasing velocity.

No fish were caught at this culvert. There is no evidence to suggest barriers downstream of the culvert, although this is one possible explanation for the absence of fish.

Replacing this culvert with an open bottom arch or open bottom box culvert could help fish access an additional 0.75 km of high quality habitat.

SC 6 – We were unable to determine if this culvert is a barrier to fish. The presence of woody debris downstream of the culvert hindered our efforts to obtain an accurate stream and culvert velocities. Therefore, debris removal is required, followed by further assessment.