Document/Issue | Mitigating Measure/Commitments/Recommendations from EA | Implemented(Yes/No) | Action Summary Reference Nos. | Additions/Exceptions |
Design of Channel Realignments | Where channel relocations cannot be avoided, the realigned watercourse reaches will be designed using natural channel design principles, by qualified technical experts (e.g., fluvial geomorphologist with input from hydrologists, fish biologists and landscape architects as appropriate). The design will involve careful consideration of the ability of the realigned stream reaches to properly convey flow and sediment (ensuring stream gradient, flow velocity/discharge are such that natural geomorphic processes will be maintained along the realigned reach). | No | AS4, AS7 | Design principles that focus on fluvial geomorphological processes are considered inappropriate for this waterway. The design team consists of water resource engineers and fisheries biologists. Inclusion of a fluvial geomorphologist on the design team is unnecessary for this undertaking. |
The new channel sections will be designed to re-instate and wherever feasible enhance the habitat features and functions that occur along the existing channel section and their inter-relationships. Features include morphological elements, particularly pool:riffle complexes, substrates, particularly mixed and coarse materials, and instream and overhanging cover. | No | AS4 | The new channel sections will be designed to include structures and features that are compatible with the local physical and natural environments. The development of pool:riffle complexes would be unsustainable due to the hydrographic characteristics of the Detroit River, which will predominately influence water levels in the new channel. |
The bankfull and low flow channel sections will be designed to match the existing channel sections (assuming similar slope conditions), or otherwise designed to maintain or enhance existing fluvial geomorphic processes that support fish habitat elements. | No | AS4 | Designing the new channel to match bank full and low flow channel sections of the existing channel sections cannot be accommodated. Doing so would substantially compromise the required drainage outlet for the tributary area. |
Maintenance or enhancement of fish movement under all relevant conditions (e.g., low flow and higher flows) will be integrated in the design and construction of the new channel section and transitions. Avoidance of potential barriers to movement will consider channel slope and velocity and potential for barriers to develop in the future in relation to channel stability (e.g., either too high/potential for degredation or too low/potential for aggredation). | Yes | AS3, AS4 | |
The details of the channel installation will be done under the direction of a fluvial geomorphologist. ‘Field fitting’ of the detailed installation of the channel sections and specific habitat components is a critical component of their installation, to ensure the stream channel and habitat maintain or enhance existing conditions and transition easily with the up and downstream reaches. | No | AS7 | Given that the design of the new channel will not focus on fluvial geomorphological principles, a fluvial geomorphologist will not direct installation of the channel works. |
Specialty Contractors with demonstrated experience in undertaking channel relocations will be used to construct channel realignment. | No | AS7 | Contractors with demonstrated experience in constructing channel improvements that are comparable to the proposed designs will be used. |
Any flow transfers required as part of the channel realignment works will be conducted during the appropriate instream work window. The flow transfer process will be carefully planned and organized to ensure the flow transfer is completed as quickly and efficiently as possible. The flow transfer will not be completed during rain or runoff events, and weather forecasts will be monitored to schedule the transfer outside of forecasted storms. | Yes | AS2 | |