Lower Welland River Characterization Report - Niagara Peninsula ...

Riffle Embeddedness (if applicable):
Lower Welland River Study Area
Characterization Report
If particles along the stream bed are completely or partially embedded then a low
score is assigned to this category.
This information collected for the 2 field sites in the Thompsons Creek watercourse is presented in
the Beaverdams and Shriners Creek Geomorphic Study, including Thompsons Creek report
(NPCA 2010e).
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Site Characterizations
As indicated earlier, during the summer months of 2010 two field sites were assessed along
Thompsons Creek. The results of the field work, as well as possible restoration alternatives are
recorded for each site in the following section.
1. Heartland Forest (TCTa): This field site is within the Provincially Significant Wetland,
Thompsons Creek Wetland. Bank instability is present in the form of undercutting and quite a
few debris jams were noted. A large debris jam was identified on the upstream side of a
footbridge which could indicate that the bridge is constricting the channel. The presence of
algae was noted during a site visit in 2010. Recommendations for this site include monitoring
bank erosion to ensure the banks are adequately stabilized. This can be done by the use of
erosion pins inserted into the bank. Additional sediment may be entering the channel through
bank erosion at the numerous debris jams present along this field site. If these debris jams are
causing more sediment to enter the channel then they should be removed. This can be
determined by monitoring the bank erosion adjacent to the debris jams with erosion pins.
Excessive sediment deposition can cause problems in the watercourse, such as lateral channel
adjustments, increased turbidity, filling in of pools, and impacting fish habitat. Measurements
taken of the foot bridge will determine whether the bridge is constricting the channel. If this is
the case then the bridge should be replaced and properly sized. Water quality should continue
to be monitored due to the presence of algae.
2. Garner Road (TCTb/TCTc/TCMc): Two tributary channels at this field site are classified as
municipal drains named Allanport Drain, class 3. Based on the 1934 aerial photograph the
channel has been altered. The presence of algae, and duckweed were noted during a site visit
in 2010. Turbid water was also noted after a storm event in 2010. The invasive species,
phragmites was identified at this field site and further research should be conducted to
determine whether the phragmites should be removed from this location. Water quality should
continue to be monitored in this watershed.
Watershed Habitat Restoration
Environment Canada (2004) in its How Much Habitat is Enough? document puts forth restoration
guidelines for wetland, riparian, and forest habitat. This framework provides “science-based
information and general guidelines to assist government and non-government restoration
practitioners, planners and others involved in natural heritage conservation and preservation by
ensuring there is adequate riparian, wetland and forest habitat to sustain minimum viable wildlife
populations and help maintain selected ecosystem functions and attributes”. Given the breadth of
science used to generate this framework, its guidelines will serve as the basis for the habitat
restoration recommendations to be implemented through the NPCA Water Quality Improvement
Program. A summary of the riparian, wetland and forest habitat restoration guidelines have been
reproduced in Appendix D.
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