Fort Erie Creeks Watershed Plan - Niagara Peninsula Conservation ...

planimetric adjustment. The index produces values that indicate whether the channel is “in
regime” or stable (0.41).
The RSAT provides a broader view of the system by also considering the ecological functioning
of the stream (Galli, 1996). This includes observations of channel stability, scour/deposition,
instream habitat, water quality, riparian conditions and biological indicators such as the
abundance of benthic invertebrates. Each indicator was ranked numerically, a lower value
indicates poorer stream health and a higher value represents a rich, healthy stream. The RSAT
score ranks the channel as maintaining a low (35) degree of
stream health. Also included in the RSAT are general observations of channel dimensions, such
as bankfull widths and depths, substrate size, bank heights, vegetation cover, channel hardening
and other disturbances.
It should be noted that not all reaches have been walked in entirety due to accessibility and time
constraints, and as a result, Table 2.4.1 represents conditions which partially characterize reaches
which were observed during field reconnaissance in November and December 2005.
Due to the fact that channel processes were inferred in the mapping and aerial photograph
analysis, field conditions were confirmed through a detailed field investigation. As such, the
following sections summarize results obtained from the detailed geomorphic assessment.
Detailed Site Assessment
Utilizing the combined RGA and RSAT scores, four reaches were chosen for more extensive
characterization. Initially, five detailed sites were chosen (one on each creek) however, due to
the marsh/backwater state of Beaver Creek; only one monitoring site was established in Reach
BVC-2.
The location of the detailed sites was determined based on the objective to provide representative
coverage of the watershed, both from a spatial and morphologic perspective. Reach BLC-9 was
chosen to provide conditions representative of Black Creek, while Reach SMC-2 was meant to
provide representative data for Six Mile Creek (downstream end). Reaches FRC-9 and MLC-3
provided insight into conditions along a particularly sensitive and geomorphologically active
section of the Local Management Area of 2.18. Finally, BVC-2 was chosen to represent
conditions at the downstream extent of the Beaver Creek where only 1 monitoring site was
established.
At each of the detailed sites, cross-sections were measured at ten locations, including pools,
riffles and transitional areas. At each cross-section, bankfull widths and depths, entrenchment,
as well as low flow dimensions were recorded. Substrate was sampled using a modified Wolman
pebble count. Sub-pavement was also characterized at each cross-section. Bank assessment
included measurements of heights, angle, bank composition, in-situ shear strength, vegetation
and rooting depths. These 10 cross-sections were placed over a minimum of two meander
wavelengths and included one control cross section located at top of bank. This control cross
section involved the installation of permanent pins in order to allow for future monitoring.
Erosion pins were also installed at each site to monitor rates of migration within the reach. A
March 2008 37 Fort Erie Creeks Watershed Plan
General Report (105116)