DISTRICT OF SQUAMISH MAMQUAM BLIND CHANNEL INTEGRATED WATERHED MANAGEMENT PLAN HAY & COMPANY CONSULTANTS Dr. Adrian Chantler, P.Eng. Maria Lau, M.Eng., E.I.T.
Ministry of Environment Dyke Inventory Map District of Squamish Mamquam River and Squamish River flowed Through area until 1920s 1921 Flood • Dyking System • Rewatering is desired
2001 Hayco Rewatering Design 2001 Hayco Rewatering Design To improve tidal-flushing: � Channel improvement of Wilson Slough � Culvert improvement at Buckley Ave. � Culvert improvement at Loggers Lane
Mamquam Reunion Mamquam Reunion � To reconnect flows from the Mamquam River back into the MBC � Brennan Channel: installation of a steel intake structure and pipeline that now delivers water into a stable rehabilitated side channel providing off-channel habitat � Loggers Lane Extension: construction of new channels and habitat, connecting into Phase I through a 30 m fish passage culvert across the Mamquam River flood dyke
r e v i R m a u q m a M Loggers Lane Connector Channel Brennan Channel N
0.28 m 3 /s 0.42 m 3 /s 0.14 m 3 /s 0.07 m 3 /s 0.14 m 3 /s 0.07 m 3 /s 0.14 m 3 /s 0.07 m 3 /s 0.42 m 3 /s 0.14 m 3 /s 0.14 m 3 /s 0.14 m 3 /s 0.28 m 3 /s 0.28 m 3 /s 0.14 m 3 /s N 0.57 m 3 /s Mamquam River Diversion Maximum Diversion Rate = 0.71 m 3 /s 0.14 m 3 /s 2005 Proposed Flow Paths
Environmental Benefits Environmental Benefits � Through this connection, water can once more flow into the formerly isolated Mamquam River Flood Plain thereby connecting directly into Loggers Lane Creek and Finch Creek � Through these channel works important anadromous fisheries stocks such as salmon (pink, coho, chum, chinook), cutthroat trout as well as other fish and wildlife species can once more swim directly from Howe Sound into the Mamquam River
N N Estuary Crossing
MBC IWMP Objectives MBC IWMP Objectives � To assess the MBC and its tributaries with the proposed diversion options � To establish the flow path for storm events � To determine the work required to reduce the risk of flooding
Hydraulic Modelling Hydraulic Modelling � Model Development � MIKE 11 Dynamic Model � Updated with recent culvert and channel improvements � Extended with Loggers Lane Creek and its tributaries � Calibrated with time-tag water levels
Storms and Tides Storms and Tides � 10-year 24-hour rainstorm = 127 mm � 100-year 24-hour rainstorm = 168 mm � Match peak runoff with highest higher high water elevation � All tide gates operating prior to high runoff and high tide events
Design Rainstorm Diversion Options Land Use Condition Dry Condition No Diversion Existing Condition � � � 10-year 24-hour Mamquam River Future Condition � � � 100-year 24-hour Squamish Estuary � � Mamquam Blind Channel Integrated Watershed Management Plan Simulation Matrix Tidal Range Culvert/Channel Improvements Design Tide Along Mamquam Blind Channel � � Largest Tide Along Loggers Lane Creek � � Smallest Tide Along Finch Creek � � Typical Large Tide + Storm Surge �
Results – – Scenario 1 Scenario 1 Results � 2001 Condition prior to channel/culvert improvements along Wilson Slough � 100-year rainstorm with future land use condition � Typical large tide plus storm surge
[m eter] 7-1-2001 00:00 5.0 4.5 260 4.0 1099 1179 1201 1220 1230 390 555 823 735 742 818 505 526 856 121 10 0 803 754 768 3.5 1016 3.0 Loggers Lane 2.5 Culverts 2.0 1.5 1.0 0.5 Buckley Culvert 0.0 Gravel Lane Culvert -0.5 Hwy 99 Culvert -1.0 -1.5 M AIN 0 - 818 M AIN 818 - 1179 M AIN -2.0 0.0 100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0 1100.0 1200.0 [m eter]
Results – – Scenario 2 Scenario 2 Results � 2005 existing condition after channel/culvert improvements along Wilson Slough � 100-year rainstorm with future land use condition � Typical large tide plus storm surge
[m eter] 7-1-2001 00:00 5.0 Wilson Slough 4.5 260 4.0 1099 1179 1199 1200 1220 1230 390 553 553 555 823 475 735 742 818 505 522 523 856 121 10 891 0 803 754 768 3.5 ROB 1016 3.0 Loggers Lane Max WL Culverts 2.5 2.0 LOB 1.5 1.0 0.5 Gravel Lane 0.0 Culvert -0.5 Hwy 99 Buckley Culvert Culvert -1.0 Channel Invert -1.5 M AIN 0 - 818 M AIN 818 - 1179 M AIN -2.0 0.0 100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0 1100.0 1200.0 [m eter]
[meter] 7-1-2001 00:00 10.0 9.5 Loggers Lane Creek 9.0 8.5 ROB 8.0 0 Robin Dr. Culverts 7.5 LOB Loggers Lane 7.0 Culverts 6.5 430 431 442 443 6.0 5.5 682 700 5.0 2181 Max WL 2091 1043 1043 1054 1055 1065 1066 861 1075 4.5 943 2064 1091 1115 2005 1143 4.0 1180 1483 1201 Raven Dr. Culvert 1415 1231 1931 1368 3.5 1295 1340 1890 1770 1661 1677 1737 1867 1569 1618 1618 3.0 Finch Dr. Culvert 2.5 2.0 1.5 Channel Invert 1.0 0.5 LOGGERS MAIN 0 - 1043 LOGGERS MAIN 1043 - 1618 LOGGERS MAIN 1618 - 2181 0.0 0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0 1600.0 1800.0 2000.0 2200.0 [meter]
Results – – Scenario 3 Scenario 3 Results � 2005 existing condition with crossing under railway connecting Squamish Estuary and Wilson Slough � Dry condition � Largest tide condition � Squamish Estuary diversion through 1 meter diameter pipe with length approx. 70 m
Results – – Scenario 4 Scenario 4 Results � 2005 existing condition with proposed crossings under Loggers Lane and Highway 99 � Dry condition � Design Tide � Mamquam River diversion (0.71 m 3 /s)
[m eter] 29-7-2001 18:40 10.0 9.5 9.0 Loggers Lane Creek 8.5 ROB 0 8.0 Robin Dr. Culverts 7.5 LOB Loggers Lane 7.0 Culverts 6.5 430 431 442 443 6.0 5.5 667 682 700 5.0 2181 Max WL 2091 861 1043 1043 1055 1054 1066 1065 1075 4.5 943 2064 1091 1115 2005 1143 4.0 1180 1483 1201 1415 1231 1931 Raven Dr. Culvert 1368 3.5 1295 1340 1890 1770 1661 1677 1737 1867 1569 1618 1618 3.0 Finch Dr. Culvert 2.5 2.0 1.5 Channel Invert 1.0 0.5 LOGGE R S M AIN 0 - 667 LOGGE R S M AIN 667 - 1043 LOGGE R S M AIN 1043 - 1618 LOGGE R S M AIN 1618 - 2181 0.0 0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0 1600.0 1800.0 2000.0 2200.0 [m eter]
Results – – Scenario 5 Scenario 5 Results � 2005 existing condition with proposed crossings under Loggers Lane and Highway 99 � Culvert improvements under Highway 99 � Culvert improvements along Loggers Lane Creek and Finch Creek � All available flap gates used at Loggers Lane � 100-year rainstorm with typical large tide plus storm surge � Mamquam River diversion (0.71 m 3 /s)
[m eter] 7-1-2001 00:00 10.0 9.5 9.0 Loggers Lane Creek 8.5 0 8.0 ROB Robin Dr. Culverts 7.5 Loggers Lane Culverts 7.0 LOB Loggers Lane Culverts 6.5 430 431 442 443 6.0 5.5 667 682 700 5.0 2181 2091 1043 1054 1055 1066 1065 861 1075 4.5 Max WL 943 2064 965 1091 1115 2005 1143 4.0 1180 1483 Raven Dr. Culverts 1201 1415 1231 1931 3.5 1368 1295 1340 1890 1770 1569 1618 1618 1661 1677 1737 1867 3.0 Finch Dr. Culverts 2.5 2.0 1.5 1.0 Channel Invert 0.5 LOGGE RS M AIN 0 - 667 LOGGE RS M AIN 667 - 1043 LOGGE RS M AIN 1043 - 1618 LOGGE RS M AIN 1618 - 2181 0.0 0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0 1600.0 1800.0 2000.0 2200.0 [m eter]
MBC IWMP 2005 Draft Report MBC IWMP 2005 Draft Report � Impacts of the various diversion options from the Mamquam River on the upper MBC would be minimal (max increase in water level approx. 0.3 m) � Existing flooding potential along the MBC � Culvert/Channel improvements along LLC and FC � Squamish Estuary crossing would help rewatering � Recommendations for mitigation works (channel/culvert improvements)
Re- -watering Project Updates watering Project Updates Re Works completed up to 2006: � Intake structure/pipe/channel to divert water from Mamquam River to Loggers Lane Creek � Ball field channel and crossing under Loggers Lane � Bio-filtration channel and culvert extension � Upper ends of natural watercourses within conservation lands south of Finch Drive � Tributary of Loggers Lane Creek along east of Highway 99 upstream and downstream of Finch Drive
Mamquam River Diversion Mamquam River Diversion � Crossing at Centennial Way to divert water from the Mamquam River (Brennan Channel) to the headwaters of Loggers Lane Creek � Constructed by DFO in 2005
Re- -watering Project Updates watering Project Updates Re Works completed up to 2006 (continued): � Channel/culvert improvements along Lower Finch Creek to the east side of Loggers Lane
Channel Improvement Bio-Filtration Pond New Rearing Ponds Lower Finch Creek Ball Field Channel and Crossings N Mamquam River Diversion Work Completed Flow Path Works Completed in 2006
Recent Rainstorms Recent Rainstorms Daily Rainfall Total at Squamish Municipal Hall � November 6, 2006 Event = 108 mm over 24-hours � November 15, 2006 Event = 146 mm over 24-hours 10-year 24-hour Rainstorm = 127 mm 100-year 24-hour Rainstorm = 168 mm
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