Long-term Flood Mitigation Options - PREFERRED OPTION Summary

In the event of a Nooksack overflow, if this option is implemented, water is anticipated to be spread out through Sumas Prairie West, which is then moved through a narrow designated floodway to the Sumas and Fraser Rivers, via a new Sumas River Pump Station. [...] DIKES SUPPORTING INFRASTRUCTURE • Permanently repair parts of Sumas Dike (make • Hwy 1 to be raised from east of Sumas First Nation temporary repairs from November 2021 permanent only) Reserve to Atkinson Road (by Province) • Modify parts of existing Sumas Dike DESIGNATED FLOODWAYS/ • Reinforce and raise parts of existing Vedder Dike CONTROLLED OVERFLOW • Relocate parts of Sumas Dike and setback t. [...] ? Modify Existing Dike toPUMP STATION ? Storage Area Improve Riparian? ? Unprotected Habitat and Create ? ? Floodplain Interpretive Trail ? ? Create Designated Upgrade Vedder Dike POTENTIAL ? ? Floodway Area (Including Barrowtown Dam and Floodboxes) ? ? ? ? Create Lake Bottom ENVIRONMENTAL ?? e r ? ? Designated Flood Retreat Sumas? Storage Area Mountain Reach Dike ? ENHANCEMENT/FLOOD ? DIKE ÎÏ Add. [...] 6 ? Sump Floodway ? ? ? ? ? ? ? Designate Flood Overflow and/or ÏÎ ? ? ? ? ? Irrigation Flow Route? ? ? Designate Flood SUMAS PRAIRIE ? ? ? ? ? ? ?? ? ? Overflow Route to5 5 "£? ? ? ? ? ? ? ? ? ?? ? ? Restore Arnold CreekOverflow to Lake WEST FLOODWAY 5 ? ? ? Bottom? "£ ? ? ?? ? ? ? 5 "£ DIKE ? ? ? ? ? ?? DIKE ? ?5 H 5 ? Sumas Prairie Build Back Better Planighway 1 5 NEW ? ??? ? ? ? ?? ? M a r s h. [...] 5 S u 5 m a s r R i v e 5 5 5 5 5 5 5 S 5 a a C r e e kr 5 5 5 55 5 n o A r l d 5 5 r e e k 5 5 5 5 ? ? S u m a s C a n a l 5? 5 5 5 5 5 5 ? 5 5 5 5 5 5 5 5 5 5 R i v 5 5 5 5 5 5 5 5 5 5 5 5 5 n a l a e r C d d V e 5 Highway 1 1.