5. Potential Effects to the Environment
5.1 Zone of Influence
Due to the run-of-river nature of the proposed development, the zone of the influence for each
facility extends from the upstream end of the proposed head pond to the downstream end of the
tailrace, where flows from the powerhouse and the bypass reach converge. The actual extent of each
facilities’ head pond has not been determined at this time and detailed topographic surveys will be
required to confirm the extent. MNR indicated in its Competitive Site Release Package that site
development was not to have an impact at Middle Falls, with MNR’s definition of no impact
meaning “no change in natural flows and levels as a result of hydro developments at Manitou Falls
and High Falls”. Further, it is MNR’s expectation “that there will be no hydraulic or hydrologic effect
within the Middle Falls reach as described as north of the upper rapids to below where Otter River
flows into the Pic River (specific locations to be determined), at any low or high flows or levels, e.g.,
flooding from Manitou Falls does not impact on the tail waters of Middle Falls”. The prefeasibility
engineering deign presented herein is intended to meet these requirements.
5.2 Potential Effects to the Environment
In order to provide a preliminary identification of the potential effects that the proposed project could
have on the environment, the Potential Effects Identification Matrix from the Class EA document
(OWA, 2008) was completed (Table 5.1). It is important to note that this table was completed using
preliminary information regarding the existing natural and socioeconomic features of the project
study area and the preliminary project design to date. The effects assessment will be refined
following completion of the baseline studies that are proposed and further refinements to the
proposed engineering design of the facilities.
The potential level of effect (positive or negative) is based on the guidance in the Class EA (OWA,
2008). Accordingly, the following definitions of effect were utilized:
a ‘nil’ effect would be assigned where there is no effect on that criterion
a ‘low’ potential effect would be assigned where the potential impact and/or benefit is
considered low or minimal
a ‘high’ potential effect would be assigned where the potential impact and/or benefit is believed
to be considerable
a ‘unk’ would be assigned where the potential effects are unknown or there is insufficient
information to assign a potential level of effect with reasonable certainty.
a ‘-‘ means a potential negative effect
a ‘+’ means a potential positive effect.
The potential effects are identified as occurring before the implementation of mitigation measures,
which would be enacted to prevent or minimize the adverse effects identified in Table 5.1. The
‘Comments, Rationale’ column in the table identifies the potential effects that could occur, and the
‘Mitigation Measures’ column identifies the measures that could potentially be implemented to
prevent or minimize adverse effects. Additional mitigation measures that could potentially be utilized
are identified in Appendix B of the Class EA (OWA, 2008).
Table 5.1 [PDF Pages: 4 Size: 100KB]