Figure Captions
Figure 1. Daily rainfall, daily
water temperature, and hourly water level along the study reach. Upper
and lower temperature limits for fish species local to Weslie Creek are
labeled on the water temperature graph (LSRCA, 2000; Eakins, 2018).
Field assessment days are shown with diamonds along the lower x-axis.
Figure 2. Reach profile from upstream (left) to downstream (right) with
representative pool (above profile) and rock weir (below profile)
cross-sections. The asterisk in the Pool 7 cross-section indicates the
stilling welling location. Vertical exaggeration is 0.08 m.
Figure 3. Fish passability in low (left), intermediate (middle), and
high (right) water level conditions. Rock weirs that provide 100% fish
passability are represented by green keystones, rock weirs that provide
fish passage for 4 or fewer fish species are represented by yellow
keystones, and rock weirs that do not provide gap or over-weir flow
pathways are represented by red keystones. Note that red keystones allow
orifice flow and leaping opportunities for fish passage. Further,
recirculation zones indicate potential locations for fish refuge during
unsuitable swimming conditions.
Figure 4. Profile schematics of a low gradient rock weir (a) and high
gradient rock weir (b). The difference in gradient depicts how
embeddedness changes depending on how gentle or steep the channel bed
is. A greater level of embeddedness provides upstream and downstream
connectivity without obstructions to the flow path (b).
Figure 5. Looking upstream at VRW2 (a low gradient rock weir) under low
(top photo), intermediate (middle photo), and high (bottom photo) water
level conditions. It is evident that orifice flow is the only active
flow regime under low water level conditions, while orifice, gap, and
over-weir flow are active simultaneously under intermediate and
high-water level conditions. VRW2 under low water level conditions
demonstrates the importance of embeddedness for enhancing fish passage
effectiveness, while VRW2 under high water level conditions demonstrates
the effect of ‘drowned conditions’.