Drain will be incorporated in the construction contract through the Detail Design drawings and stipulations contained in Special Provisions and Operational Constraints of the Contract.

4.2.1 Changes or alterations to water quality and quantity

• Best construction practices will be employed to reduce the potential for spills and materials/equipment from entering water.

• Maintenance, fuelling and storage will occur at least 30 m from watercourses/drains.

• Debris will be prevented from entering watercourses/drains to the greatest extent possible, and a spill response plan will be developed.

• A stormwater management plan will be developed and implemented to treat run-off during operations.

• Stormwater runoff associated with the Plaza construction will be treated in stormwater management wet ponds designed in accordance to the MOE document “Stormwater Management Planning and Design Manual” for Enhanced Protection Level.

• In addition, the stormwater management ponds will provide quantity storage to control peak flows from the Plaza to pre-development rates.

4.2.2 Alterations to baseflow

• The increases in impervious surfaces and areas of soil compaction will be minimized to facilitate as much infiltration of surface water as possible.

• Management of stormwater through the development and implementation of a stormwater management plan will address potential reductions in baseflow.

• Methods that encourage infiltration will be investigated.

• Flows in watercourses will be monitored during dewatering activities and measures should be implemented in the event that baseflow is significantly affected.

4.2.3 Barriers to fish passage

• Water flow will be maintained during construction.

• Culverts, designed using fish-friendly methods, and channels, designed using natural channel design principles, will not form barriers to fish passage during operations.