STABLE DYNAMIC BEACH MODELLING FRAMEWORK

GEOMORPHIC SOLUTIONS 141 Brunel Road Mississauga, ON L4Z 1X3 T 416 213 7121 F 95 89 8499 www.geomorphicsolutions.ca STABLE DYNAMIC BEACH MODELLING FRAMEWORK Geomorphic & Environmental Sciences Hazard Land Assessment Creek Rehabilitation Water Resources Management Prepared for: International Joint Commission as part of the International Upper Great Lakes Study February 211 176.45

TABLE OF CONTENTS PAGE TABLE OF CONTENTS... i LIST OF FIGURES... ii LIST OF TABLES... iii 1. INTRODUCTION... 1 1.1 SITE SELECTION... 1 2. MODELLING CONDITIONS... 3 2.1 CROSS-SHORE PROFILES... 3 2.1.1 Burley Beach... 3 2.1.2 Wasaga Beach... 4 2.1.3 Thunder Beach... 4 2.2 OFFSHORE BATHMETRY... 6 2.3 WATER LEVELS... 7 2.3.1 Burley Beach... 8 2.3.2 Thunder Beach and Wasaga Beach... 9 2.3.3 Coastal Zone TWG Regulation Plan Water Levels... 11 2.4 STORM SURGES... 14 2.5 WAVES... 15 2.5.1 Burley Beach... 16 2.5.2 Wasaga Beach... 17 2.3.3 Thunder Beach... 19 2.6 SEDIMENT... 2 2.6.1 Grain Size... 2 2.6.2 Sediment Transport Parameters... 21 3. SBEACH MODELLING... 22 3.1 MODEL DURATION... 22 3.2 MODEL SCENARIOS... 22 4. REFERENCES... 26 i

LIST OF FIGURES PAGE Figure 1. Location of Study Sites... 2 Figure 2. Burley Beach onshore profile... 3 Figure 3. Wasaga Beach onshore profile... 4 Figure 4. Thunder Beach onshore profile... 5 Figure 5. Burley Beach offshore profile... 6 Figure 6. Wasaga Beach offshore profile... 7 Figure 7. Thunder Beach offshore profile... 7 Figure 8. Goderich monthly mean water levels (192-27)... 8 Figure 9. Histogram and normal distribution of Goderich monthly mean water levels (192 27)... 9 Figure 1. Collingwood monthly mean water levels (1916-27)... 1 Figure 11. Histogram and normal distribution of Collingwood monthly mean water levels (1916 27)... 1 Figure 12. Coastal Zone TWG regulation plan water level scenarios... 12 Figure 13 Histograms and normal distributions of the Coastal Zone TWG regulation plan water level scenarios... 13-14 Figure 14. Extreme value analysis for significant wave height at hindcast site LH49 (1965 1987)... 16 Figure 15. Significant wave height and wave period for the largest storm event in the 32 year record at Hindcast site LH49... 17 Figure 16. Significant wave height and wave period for the largest storm event in the 34 year record at Hindcast site GB4... 18 Figure 17. Significant wave height and wave period for the largest storm event in the 34.9 year record at Hindcast site GB6... 2 ii

LIST OF TABLES PAGE Table 1. Water levels for modelling... 14 Table 2. Surge Frequencies - MNR... 15 Table 3. Surge Frequencies - Baird... 15 Table 4. Extreme value analysis for wave heights at Hindcast site LH49... 16 Table 5. Extreme value analysis for wave heights at Hindcast site GB4... 18 Table 6. Extreme value analysis for wave height at Hindcast site GB6... 19 Table 7. Grain Sizes for modelling scenarios... 21 Table 8. Modelling scenarios for Burley Beach... 23 Table 9. Modelling scenarios for Wasaga Beach... 24 Table 1. Modelling scenarios for Thunder Beach... 25 iii

1. INTRODUCTION This report has been completed in support of the International Joint Commission s (IJC) International Upper Great Lakes Study (IUGLS). As discussed in the Introduction to Stable Dynamic Beach Assessment report (Geomorphic Solutions, 21) and the Erosion Theme Report (Baird, 21b), part of the IUGLS mandate is to determine the potential impacts of alternative water level scenarios as a result of regulating the outflow of Lake Superior. The future water level scenarios could be outside of historical ranges and impact private property or infrastructure close to the current limit of cutback on stable dynamic beaches. The report follows the Introduction to Stable Dynamic Beach Assessment Report (Geomorphic Solutions, 21). The aim is to summarize the Storm-induced BEAch CHange Model (SBEACH) modelling approach, which was used to determine the potential impacts upon the shoreline given the proposed water level scenarios under a variety of storm events. For more information on the SBEACH model, please refer to Scoping exercise to review available predictive models for cohesive and sandy shoreline erosion on the upper Great Lakes along with their associated uncertainties Report (Geomorphic Solutions, 29) and Geomorphic Solutions (21). 1.1 SITE SELECTION In 21, Baird & Associates, in conjunction with the Coastal Zone Technical Working Group (Coastal Zone TWG) compiled a list of potential study sites along the shoreline of the Great Lakes based on a selection criteria. Criteria included sensitivity to water level fluctuations, availability of data and the site s ability to represent lakewide conditions. Sites along the east (Canadian) coast of Lake Huron and Georgian Bay included Central Bruce, Simcoe, Lambton and Huron Counties, Saginaw Bay, Muskoka Municipality and Parry Sound Districts (Baird, 21a). Three sandy stable dynamic beach sites along the east coast of Lake Huron were selected for this study. Of the three sites, two (Wasaga and Thunder Beach) are located along the shores of Simcoe County, southeastern Georgian Bay and one (Burley Beach, Pinery Provincial Park) along the shores of Lambton County, southern Lake Huron (Figure 1). In general, the three sites are sandy beaches, which respond to fluctuations in water levels, yet do not experience long term erosion. The sites were selected based on data availability and the fact that they represent a range of conditions. Wasaga Beach was chosen as an example of a dissipative beach. Dissipative beaches have gently sloping nearshores where waves break over a wide area and one or more bars are usually present. Burley and Thunder beaches are more reflective. Reflective beaches have steep nearshores and waves break directly on the beach face. Wave energy varies among the sites with the highest occurring at Burley Beach. 1

Figure 1: Location of study sites. 2

2. MODELLING CONDITIONS Six key datasets required to complete the stable dynamic beach modelling include: cross-shore profiles, offshore bathymetric profiles, monthly mean water level scenarios, storm surge, wave climate and sediment size. These datasets are described in detail below. 2.1 CROSS-SHORE PROFILES Cross-shore profiles were derived from a number of sources. This section will outline the methods used to compile the overall dataset for model input. Profile section breaks denote the source. All profiles were merged using linear interpolation to fill in the profile gap. Note the vertical scale of the profile is exaggerated. New surveys were not made at all the sites. This was unnecessary given that only a generic profile was required for each site which represented the general form of the beach. 2.1.1 Burley Beach Pinery 8 Dr. Chris Houser (Texas A&M University) kindly provided beach cross-shore profiles of Burley Beach (Houser & Greenwood, 25a; 25b). During September and October of 21, six crosssections of the beach and dune at Burley Beach, Pinery Provincial Park were surveyed. Of the six cross-sections, the beach profile of profile # 3 was selected for modelling purposes as the most information was available for this site. The backdune and foredune profile was provided by Dr. Mary-Louise Byrne (Wilfred-Laurier University). During May 27, 25 Burley Beach was surveyed using a Leica dual frequency, differential, real-time kinematic GPS. The final cross-shore profile was created from an amalgamation of C. Houser and M-L. Byrne data (Figure 2). 6 Elevation (m, CD) 4 2 M-L Byrne Level Survey C. Houser Level Survey -2-4 -1-75 -5-25 25 5 75 1 125 15 Distance (m) Figure 2: Burley Beach profile (Elevations relative to Chart Datum: 176.m above IGLD85). 3

2.1.2 Wasaga Beach 6 The beach face, backshore, foredune and backdune were determined by combining a photographic interpretation from a site reconnaissance carried out by Geomorphic Solutions on July 22 nd, 21 and surveys provided by A. Crowe (Environment Canada). This approach was necessary due to access issues. Nearshore profiles were surveyed by Dr. Robin Arnott-Davidson (University of Guelph) in June, 1981. Profile # O was selected for modelling purposes as it best represented a typical nearshore profile of a dissipative beach. The final cross-shore profile was created by amalgamating the profile components (Figure 3). 5 4 Elevation (m, CD) 3 2 1 R. Davidson-Arnott Level Survey -1 Estimated Profile -2-1 -5 5 1 15 2 Distance (m) Figure 3: Wasaga Beach profile (Elevations relative to Chart Datum: 176.m above IGLD85). 2.1.3 Thunder Beach The surf zone, beach face and foredune were surveyed by Geomorphic Solutions on July 22 nd, 21. The backdune was determined through photographic interpretation from the site visit. Cross sectional nearshore profiles were surveyed by R. Davidson-Arnott in May, 1977. Profile # K was selected for modelling purposes as it best represented a typical reflective nearshore profile of a dissipative beach. The final profile was created from an amalgamation of Geomorphic Solutions and R. Davidson Arnott measurements (Figure 4). 4

5 Level Survey 3 Estimated Dune Elevation (m, CD) 1-1 -3-5 -1-75 -5-25 25 5 75 1 125 15 Distance (m) Figure 4: Thunder Beach profile (Elevations relative to Chart Datum: 176.m above IGLD85). 5

2.2 OFFSHORE BATHYMETRY The bathymetry for the study was based on the National Ocean and Atmospheric Administration (NOAA) GEODAS for the Great Lakes (NOAA, 21a). Bathymetric depths are shown as metres below Chart Datum (International Great Lakes Datum IGLD85). Lake Huron Chart Datum is 176. m IGLD85. Three offshore profiles, corresponding to the location of the shoreline profiles were extracted perpendicular to the shoreline, from the bathymetry. The profiles extend from a depth of m below chart datum to approximately 45 m below chart datum. All bathymetry profiles were merged with the nearshore / onshore profiles using linear interpolation to fill in the profile gap. A comparison of the offshore profiles is shown in Figures 5, 6 and 7. Note that the vertical scale of the profile is exaggerated. -2.5 NOAA - GEODAS Bathymetry -5 Elevation (m, CD) -7.5-1 -12.5-15 Figure 5: 5 1 15 2 25 Distance (m) Burley Beach offshore profile (Elevations relative to Chart Datum: 176.m above IGLD85). 6

5 NOAA - GEODAS Bathymetry Elevation (m, CD) -5-1 -15-2 5 1 15 2 25 3 35 4 45 Distance (m) Figure 6: Wasaga Beach offshore profile (Elevations relative to Chart Datum: 176.m above IGLD85). 5-5 -1 NOAA - GEODAS Bathymetry Elevation (m, CD) -15-2 -25-3 R. Davidson-Arnott Echo Soundings -35-4 -45 5 1 15 2 25 3 Distance (m) Figure 7: Thunder Beach offshore profile (Elevations relative to Chart Datum: 176.m above IGLD85). 2.3 WATER LEVELS An overall review of the long-term water levels as shown in Figures 8 and 1, demonstrates that water levels in Lake Huron have varied significantly. The recorded high and low monthly water levels reached 177.5 m in October 1986 and 175.58 m in March 1964 respectively (NOAA, 21b). 7

2.3.1 Burley Beach Approximately 87 years of monthly mean water levels were obtained from Goderich (Station gauge ID # 1186, 43 o 45 1.5 N, 81 o 44 52.3 W) on Lake Huron (nearest gauge located approximately 55 km north of Pinery Provincial Park) for the period 192-27 (Figure 8 and 9). 177.75 Goderich Monthly Means 192-27 Mean Water Level 177.25 Elevation (m, IGLD'85) 176.75 176.25 175.75 175.25 192 193 194 195 196 197 198 199 2 21 Time Figure 8: Goderich monthly mean water levels (192-27) (NOAA, 21b) 8

Goderich Measured Water Levels 12 Mean = 176.43-2 s.d -1 s.d +1 s.d +2 s.d 8 Frequency 4 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) Figure 9: Histogram and normal distribution of Goderich monthly mean water levels (192-27) (NOAA, 21b) 2.3.2 Thunder and Wasaga Beach Approximately 91 years of monthly mean water levels were obtained from Collingwood (Station gauge ID # 115, 44 o 31. N, 8 o 13 4. W) on Lake Huron (nearest gauge located approximately 15 km west of Wasaga Beach and 35 km southwest of Thunder Beach) for the period 1916 27 (Figure 1 and 11). 9

177.75 Collingwood Monthly Means 1916-27 Mean Water Level 177.25 Elevation (m, IGLD'85) 176.75 176.25 175.75 175.25 1915 1925 1935 1945 1955 Figure 1: Collingwood monthly mean water levels (1916 27) (NOAA, 21b) Time 1965 1975 1985 1995 25 12 Collingwood Measured Water Levels Mean = 176.48-2 s.d -1 s.d +1 s.d +2 s.d 8 Frequency 4 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) Figure 11: Histogram and normal distribution of Collingwood monthly mean water levels (1916-27) (NOAA, 21b) 1

2.3.3 Coastal Zone TWG Regulation Plan Water Levels As discussed in Geomorphic Solutions (21) and Baird, (21a), part of the IUGLS mandate is to determine the potential impacts of various water level scenarios as a result of regulating the outflow of Lake Superior. The IJC provided static monthly mean water levels for the upper Great Lakes which were modelled for a 17 year period starting from 19 and ending in 26. The modelled scenarios correspond to the following: P77A = Plan 1977A. This is the current regulation strategy for the flow control structures on the St. Mary s River. P122 = Plan 122. P55 = 55ModRule49. MH = Superior for Lake Michigan Huron. The release of water from Lake Superior into Lake Michigan-Huron is optimised in an attempt to mitigate the fluctuation of water levels in Lake Michigan-Huron. This fence post plan disregards impacts on Lake Superior and connecting channels. S4S = Superior for Superior. Monthly mean lake levels on Lake Michigan-Huron based on an attempt to sustain Lake Superior s water levels close to the measured monthly long term averages. Similar to MH, this fencepost plan does not consider downstream impacts, since the average water levels on Lake Superior are maintained. Q1887 = PreProject. The water level of Lake Michigan-Huron is determined by the outflow equation for Lake Superior. This outflow equation was developed in the 188 s prior to the construction and modification of flow due to control structures. Figure 12 shows the six 17 year monthly means for Lake Michigan-Huron. Water levels for S4S, Q1887, P122 and P55 scenarios ranged between 175.39 and 177.5 m with a mean of ~ 176.35 m. 11

178 177.5 177 Elevation (m, IGLD'85) 176.5 176 175.5 175 MH P55 P77A P122 Q1887 S4S 19 191 192 193 194 195 196 197 198 199 2 21 Time Figure 12: Coastal Zone TWG regulation plan water level scenarios. A histogram and normal distribution was computed to assess the mean and standard deviations for each scenario (Figures 13). Based on the mean, standard deviation and frequency of occurrence of water levels, a range of high water levels was determined for modelling input (Table 1). 12

a) b) Modelled MH Mean = 176.346 2 16 Modelled P55 Mean = 176.346-1 s.d +1 s.d -1 s.d +1 s.d -2 s.d +2 s.d -2 s.d +2 s.d 16 12 12 Frequency Frequency 8 8 4 4 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) c) d) Modelled P77A 16 Mean = 176.352 16 Modelled P122 Mean = 176.354-1 s.d +1 s.d -1 s.d +1 s.d -2 s.d +2 s.d -2 s.d +2 s.d 12 12 Frequency 8 Frequency 8 4 4 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) 13

e) f) Modelled Q1887 Modelled S4S 16 Mean = 176.352 16 Mean = 176.344-1 s.d +1 s.d -1 s.d +1 s.d -2 s.d +2 s.d -2 s.d +2 s.d 12 12 Frequency 8 Frequency 8 4 4 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) 175 175.5 176 176.5 177 177.5 Elevation (m, IGLD'85) Figures 13: Histograms and normal distributions of the Coastal Zone TWG regulation plan water level scenarios. The water levels which will be used for modelling for all storm conditions range between 177 to 178 m (IGLD 85). These values selected are within and above the historical and Coastal Zone TWG modelled monthly means. Table 1: Water levels for modelling m, CD m, IGLD 85 m, CD m, IGLD 85 1. 177 1.6 177.6 1.1 177.1 1.7 177.7 1.2 177.2 1.8 177.8 1.3 177.3 1.9 177.9 1.4 177.4 2. 178 1.5 177.5 2.4 STORM SURGES Water levels on Lake Huron vary both in the long-term and seasonally in response to climatic conditions. They also vary in the short term due to the passing of storms. The passing of storms typically create storm surges, and occur when there is a local increase in the water level caused by high wind stresses applied to the water surface, drops in atmospheric pressure and movement of pressure systems (Danard et al., 23). Since the short-term storm surge and the longer term and seasonal lake level variations have different driving mechanisms, it is important to assess the storm surge and the mean water level independently. The storm surge and mean water levels can then be amalgamated to create the worst-case scenarios. Note that set up due to waves is determined by the SBEACH Model. Storm surge used in the modelling was derived from the Ministry of Natural Resources (MNR) Great Lakes System Flood Levels guideline (MNR, 1989). The MNR guideline provides a calibrated record of the 14

flooding frequencies over a 2 to 2 year return period for the Great Lakes based on the SURGE model operated by Environment Canada. Table 2 shows the expected height of surge events over the 1, 25, 5, 1 and 2 year return periods at sites proximal to Burley, Wasaga and Thunder Beach. Table 2: Surge events (MNR, 1989) Location/ Return Period (yr) Collingwood (44 o 31 12.11 N, 8 o 13 3.78 W) Wasaga and Thunder Beach Kettle Point (43 o 11 34. N, 82 o 48. W) Burley Beach Surge (m) 1 25 5 1 2.68.78.85.93 1.1.59.66.72.78.84 Surge analysis within the Great Lakes was carried out recently by Baird (21c) using 48 years of hourly water levels. The data for Collingwood (Station gauge ID # 115, 44 o 31. N, 8 o 13 4. W), which is proximal to Wasaga and Thunder Beach, are shown in Table 3. Table 3: Surge events (Baird, 21c) Location / Return Period (yr) Collingwood # 115 -Wasaga & Thunder Beach Surge (m) 2 5 1 1 5.43.48.53.67.77 Surge values obtained from MNR (1989) for the 1 and 1 year return periods are.15 m and.26 m (respectively) higher than those recorded by Baird (21c). Since the aim of this study is to assess the potential impact of the shoreline due to a worst-case storm scenario, the higher surge values were used in the model. 2.5 WAVES 32 and 34.9 years of hindcast records were obtained from USACE (21) and Philpotts (1988) respectively. This section will outline the methods used to determine the wave period and significant wave height return periods used in the modelling. The wave direction for all storms is set to approach the shoreline at 9 o (perpendicular to the shoreline), since the modelling is employing a worst-case scenario approach. In reality this would not be the case and waves would be generated in all directions depending on the local wind direction. Assuming all waves are directed towards the test sites generates the highest potential wave energy at the shoreline for the given storm event. 15

2.5.1 Burley Beach 32 years (1956 1987) of hindcast data for Southern Lake Huron (Hindcast site # LH49, 43 o 3 N, 81 o 58 17 W) was obtained from the Wave Information Studies (WIS), generated by the U.S. Army Corps of Engineers (USACE, 21). LH49 is located approximately 25 km offshore in a north-westerly direction from Burley Beach. In order to calculate the significant wave height (H sig ) for various return periods, a Weibull Distribution was fitted to the data, shown in Figure 14, and Table 4. 9% C.I. 9% C.I. Figure 14: Table 4: Extreme value analysis for significant wave height at Hindcast site LH49 Southern Lake Huron (1956 1987) (USACE, 21). Extreme value analysis for wave heights at Hindcast site LH49, Southern Lake Huron (USACE, 21). Return Period (yr) Significant wave height (H sig, m) 1 5.25 5 6.4 1 6.85 2 7.2 5 7.8 1 8.2 16

The largest storm within the 32-year hindcast record occurred during March 29 th 31 st, 1984. Significant wave height reached a peak of 8 m, with a peak period (T p ) of 11. This, in accordance to the Extreme Value Analysis carried out suggests that this storm had a return period of 52 years (Figure 15). In order to simulate the significant wave height distribution of both the 5 and 1 year storms, the hindcast of this storm was extracted from the dataset. The distribution of wave heights over this storm was used for the 5 and 1-year storms by adjusting to match the peak significant wave heights for each return period. The wave period remains unadjusted. 9 8 7 Largest storm in 32 - year record T p (52 - year return period) Largest storm in 32 - year record H sig (52 - year return period) Projected 5 - year H sig Projected 1 - year H sig 12 1 Significant Wave Height (m) 6 5 4 3 8 6 Significant Wave Period (sec) 2 1 4 3/29/84 3/3/84 3/31/84 Time Figure 15: Significant wave height and wave period for the largest storm event in the 32 year record at Hindcast site LH49, and modifications to generate 5 and 1- year storms. Southern Lake Huron (USACE, 21), 2.5.2 Wasaga Beach 34.9 years (1953 1987) of wave hindcast data for Collingwood Georgian Bay (Hindcast site # GB4, 44 o 3 6 N, 8 o 2 3 W) was generated by the MNR (Philpotts, 1988). GB4 is located approximately 15 km offshore in a north-westerly direction from Wasaga Beach. The significant wave height return period (Table 5) was calculated by Philpotts (1988) using the Weibull Distribution. 17

Table 5: Extreme value analysis for wave heights at Hindcast site GB4, Collingwood (Philpotts, 1988). Return Period (yr) Significant wave height (H sig, m) 1 4.7 5 5.4 1 5.7 2 5.9 5 6.3 1 6.6 The largest storm within the 34-year record occurred during November 3 rd 5 th, 1965. Significant wave heights reached a peak of 6 m, with a peak wave period of 11.2. In order to simulate the significant wave height distribution over both the 5 and 1 year storms at Wasaga Beach, the wave hindcast of the November 1965 storm was extracted from the dataset. The significant wave height of the hindcast storm was adjusted to match the peak significant wave heights of the 5 and 1-year storms. The wave period remains unadjusted (Figure 16). 8 12 7 6 Largest storm in 34 - year record T p Largest storm in 34 - year record H sig Projected 5 - year H sig Projected 1 - year H sig 1 Significant Wave Height (m) 5 4 3 8 6 Significant Wave Period (sec) 2 4 1 2 11/3/65 11/4/65 11/5/65 Time Figure 16: Significant wave height and wave period for the largest storm event in the 34 year record at Hindcast site GB4, and modifications to generate 5 and 1- year storms, Collingwood (Philpotts, 1988). 18

2.5.3 Thunder Beach The same approach was used for Wasaga Beach. 34.9 years (1953 1987) of hindcast data for 12 Mile Bay Georgian Bay (Hindcast # GB6, 45 o N, 8 o 3 32 W) was obtained from Philpotts (1988). GB6 is located approximately 43 km offshore in a north-north-westerly direction from Thunder Beach. The wave height return period was calculated by Philpotts (1988) using the Weibull Distribution. Table 6: Extreme value analysis for wave heights at Hindcast site GB6, Twelve Mile Bay. (Philpotts, 1988). Return Period (yr) Significant wave height (Hsig, m) 1 4.8 5 5.4 1 5.6 2 5.9 5 6.2 1 6.4 The largest storm within the 34.9-year record occurred during November 3 rd 5 th, 1965. Wave heights reached a peak of 5.7 m, with a peak wave period of 1.8 seconds. In order to simulate the distribution of significant wave heights for both the 5 and 1 year storms at Thunder Beach, the wave hindcast of the November 1965 storm was extracted from the dataset. The significant wave height of the hindcast storm was adjusted to match the peak significant wave heights of the 5 and 1-year storms. The wave period remains unadjusted (Figure 17). 19

7 12 6 Largest storm in 34 - year record T p Largest storm in 34 - year record H sig Projected 5 - year H sig Projected 1 - year H sig 1 5 Significant Wave Height (m) 4 3 8 6 Significant Wave Period (sec) 2 4 1 2 11/3/65 11/4/65 11/5/65 Time Figure 17: Significant wave height and wave period for the largest storm event in the 34.9 year record at Hindcast site GB6, and modifications to generate 5 and 1- year storm events, Twelve Mile Bay (Philpotts, 1988). 2.6 SEDIMENT 2.6.1 Grain Size The grain size for Burley Beach was obtained from Houser & Greenwood (25a, 25b) and corresponds to profile # 3 surveyed in October 21. The upper shoreface and beach was composed of fine sand with a mean grain size (D 5 ) of.19 mm (Houser & Greenwood, 25a, 25b) (Table 7). The grain size for Wasaga Beach was obtained from Davidson- Arnott (1981) and corresponds to profile # O surveyed in June 1981. The beach was composed of fine to very fine sand with a D 5 of.9 mm (Table 7). It was noted that this sample was taken at the beach face and that there was a gradual fining of grain sizes with increasing distance to the nearshore zone. The grain size for Thunder Beach was obtained from Davidson- Arnott (1977) and corresponds to profile # K surveyed in May 1977 (Table 7). The beach was composed of medium to fine sand with a D 5 of.16 mm. Variations of grain size were incorporated into the modelling to investigate the impact of grain size on shoreline erosion. This will provide insight into the applicability of the model results to other locations. For each test site, the field measured D 5 and two other D 5 will be used. The following grain sizes were used at each site (Table 7). 2

Table 7: Grain sizes for modelling scenarios Site / Grain Size Field measured D5 (mm) Coarser scenario D5 (mm) Medium scenario D5 (mm) Finer scenario D5 (mm) Burley Beach.19.3.19.1 Wasaga Beach.1.3.2.1 Thunder Beach.16.3.16.1 2.6.2 Sediment Transport Parameters As discussed in Geomorphic Solutions (21), the transport of sediment within the nearshore, surf zone and swash zones are highly dependent on the interaction of waves and currents. The SBEACH model requires a number of calibration parameters for sediment transport calculations as discussed by Larson et al. (199), Larson (1992) and Rosati et al. (1993). The following outlines the parameters used in the modelling based on trial simulations. The results are discussed in Geomorphic Solutions (211). Transport rate coefficient (K). Typical transport rate K values range between.5 x 1-6 to 2.5 x 1-6 m 4 /N for sandy beaches (Larson & Kraus, 1989). A value of.5 x 1-6 m 4 /N was used. Coefficient for slope dependent term (ε). Typical ε values range between.1 to.5 m 2 /s. The median value of.2 m 2 /s was used. Transport rate decay coefficient multiplier. This is the sediment transport rate between the breaker zone and the wave restructuring point to the next breaking point. Sediment transport rates decay according to this parameter ranges between.1 and.5. The smaller the values of the parameter will result in a lower amount of decay. A value of.5 was used. Water temperature. The settling velocity of sediment depends on water temperature, due to density. Since the majority of storms occur during the Fall, the average October temperature of 9.6 o C was used. For more additional details on the deterministic calculation of sediment transport parameters, please refer to Larson et al. (199), Larson (1992) and Rosati et al. (1993). For more information on the Sensitivity Analysis which determined the model input parameters, please refer to Geomorphic Solutions (211). 21

3. SBEACH MODELLING Following the sensitivity analysis, SBEACH was used to estimate the profile change at the +1 to 2 m, CD water levels and the largest in 32 - year for Burley Beach, the largest in 34 year for Thunder and Wasaga Beach, the 5 year and the 1 year wave conditions for all three study sites. 3.1 MODEL DURATION Two different lengths of model simulation were used; a 2 day (48 hours) and a 4 day (96 hours) storm event. The 48 hour time period was selected to provide sufficient time for the simulation of one complete storm event. The 96 hour duration was simulated using two consecutive 48 hour storm events to determine the state of equilibrium. 3.2 MODEL SCENARIOS A number of storm conditions were generated based on the Coastal Zone TWG modelled water levels, and data collated and analysed by Geomorphic Solutions. The following tables (Tables 8 1) outline the modelling conditions for each site. 22

Table 8: Modelling Scenarios for Burley Beach varying water level scenarios and wave characteristics (Elevations relative to Chart Datum: 176. m above IGLD85). Run # Storm Event Water Level (m, CD) Peak Surge (m) Burley Beach WL + Peak Surge (m, CD) Peak H sig (m) Peak T p (s) Sediment Size D 5 (mm) B1 1.66 1.66.19 48 B2 1.1.66 1.76.19 48 B3 1.2.66 1.86.19 48 B4 1.3.66 1.96.19 48 B5 1.4.66 2.6.19 48 Largest in 32 yr Hindcast B6 8. 11. record (L32) 1.5.66 2.16.19 48 B7 1.6.66 2.26.19 48 B8 1.7.66 2.36.19 48 B9 1.8.66 2.46.19 48 B1 1.9.66 2.56.19 48 B11 2.66 2.66.19 48 B12 1.72 1.72.19 48 B13 1.1.72 1.82.19 48 B14 1.2.72 1.92.19 48 B15 1.3.72 2.2.19 48 B16 1.4.72 2.12.19 48 B17 5 yr Storm (S5) 1.5.72 2.22 7.8 11..19 48 B18 1.6.72 2.32.19 48 B19 1.7.72 2.42.19 48 B2 1.8.72 2.52.19 48 B21 1.9.72 2.62.19 48 B22 2.72 2.72.19 48 B23 1.78 1.78.19 48 B24 1.1.78 1.88.19 48 B25 1.2.78 1.98.19 48 B26 1.3.78 2.8.19 48 B27 1.4.78 2.18.19 48 B28 1 yr Storm (S1) 1.5.78 2.28 8.2 11..19 48 B29 1.6.78 2.38.19 48 B3 1.7.78 2.48.19 48 B31 1.8.78 2.58.19 48 B32 1.9.78 2.68.19 48 B33 2.78 2.78.19 48 B34 1.66 1.66.19 96 B35 1.1.66 1.76.19 96 B36 1.2.66 1.86.19 96 B37 1.3.66 1.96.19 96 B38 1.4.66 2.6.19 96 Largest in 32 yr Hindcast B39 8. 11. record (L32) 1.5.66 2.16.19 96 B4 1.6.66 2.26.19 96 B41 1.7.66 2.36.19 96 B42 1.8.66 2.46.19 96 B43 1.9.66 2.56.19 96 B44 2.66 2.66.19 96 B45 1.72 1.72.19 96 B46 1.1.72 1.82.19 96 B47 1.2.72 1.92.19 96 B48 1.3.72 2.2.19 96 B49 1.4.72 2.12.19 96 B5 5 yr Storm (S5) 1.5.72 2.22 7.8 11..19 96 B51 1.6.72 2.32.19 96 B52 1.7.72 2.42.19 96 B53 1.8.72 2.52.19 96 B54 1.9.72 2.62.19 96 B55 2.72 2.72.19 96 B56 1.78 1.78.19 96 B57 1.1.78 1.88.19 96 B58 1.2.78 1.98.19 96 B59 1.3.78 2.8.19 96 B6 1.4.78 2.18.19 96 B61 1 yr Storm (S1) 1.5.78 2.28 8.2 11..19 96 B62 1.6.78 2.38.19 96 B63 1.7.78 2.48.19 96 B64 1.8.78 2.58.19 96 B65 1.9.78 2.68.19 96 B66 2.78 2.78.19 96 B67 Largest in 32 yr Hindcast 2.66 2.66.1 96 8. 11. B68 record (L32) 2.66 2.66.3 96 B69 2.72 2.72.1 96 5 yr Storm (S5) 7.8 11. B7 2.72 2.72.3 96 B71 1 yr Storm (S1) 2.78 2.78 8.2 11..1 96 B72 2.78 2.93.3 96 Duration (hrs) Geomorphic Solutions 176 Stable Dynamic Beach Modelling Results 23

Table 9: Modelling Scenarios for Wasaga Beach varying water level scenarios and wave characteristics (Elevations relative to Chart Datum: 176. m above IGLD85). Wasaga Beach Run # Storm Event Water Level (m, CD) Peak Surge Level (m) WL + Peak Surge Level (m, CD) Peak H sig (m) Peak T p (s) Sediment Size D 5 (mm) Duration (hrs) W1 1.78 1.78.1 48 W2 1.1.78 1.88.1 48 W3 1.2.78 1.98.1 48 W4 1.3.78 2.8.1 48 W5 1.4.78 2.18.1 48 Largest in 34 yr Hindcast W6 1.5.78 2.28 6. 11.2.1 48 record (L34) W7 1.6.78 2.38.1 48 W8 1.7.78 2.48.1 48 W9 1.8.78 2.58.1 48 W1 1.9.78 2.68.1 48 W11 2.78 2.78.1 48 W12 1.85 1.85.1 48 W13 1.1.85 1.95.1 48 W14 1.2.85 2.5.1 48 W15 1.3.85 2.15.1 48 W16 1.4.85 2.25.1 48 W17 5 yr Storm (S5) 1.5.85 2.35 6.3 11.2.1 48 W18 1.6.85 2.45.1 48 W19 1.7.85 2.55.1 48 W2 1.8.85 2.65.1 48 W21 1.9.85 2.75.1 48 W22 2.85 2.85.1 48 W23 1.93 1.93.1 48 W24 1.1.93 2.3.1 48 W25 1.2.93 2.13.1 48 W26 1.3.93 2.23.1 48 W27 1.4.93 2.33.1 48 W28 1 yr Storm (S1) 1.5.93 2.43 6.6 11.2.1 48 W29 1.6.93 2.53.1 48 W3 1.7.93 2.63.1 48 W31 1.8.93 2.73.1 48 W32 1.9.93 2.83.1 48 W33 2.93 2.93.1 48 W34 1.78 1.78.1 96 W35 1.1.78 1.88.1 96 W36 1.2.78 1.98.1 96 W37 1.3.78 2.8.1 96 W38 1.4.78 2.18.1 96 Largest in 34 yr Hindcast W39 1.5.78 2.28 6. 11.2.1 96 record (L34) W4 1.6.78 2.38.1 96 W41 1.7.78 2.48.1 96 W42 1.8.78 2.58.1 96 W43 1.9.78 2.68.1 96 W44 2.78 2.78.1 96 W45 1.85 1.85.1 96 W46 1.1.85 1.95.1 96 W47 1.2.85 2.5.1 96 W48 1.3.85 2.15.1 96 W49 1.4.85 2.25.1 96 W5 5 yr Storm (S5) 1.5.85 2.35 6.3 11.2.1 96 W51 1.6.85 2.45.1 96 W52 1.7.85 2.55.1 96 W53 1.8.85 2.65.1 96 W54 1.9.85 2.75.1 96 W55 2.85 2.85.1 96 W56 1.93 1.93.1 96 W57 1.1.93 2.3.1 96 W58 1.2.93 2.13.1 96 W59 1.3.93 2.23.1 96 W6 1.4.93 2.33.1 96 W61 1 yr Storm (S1) 1.5.93 2.43 6.6 11.2.1 96 W62 1.6.93 2.53.1 96 W63 1.7.93 2.63.1 96 W64 1.8.93 2.73.1 96 W65 1.9.93 2.83.1 96 W66 2.93 2.93.1 96 W67 Largest in 34 yr Hindcast 2.78 2.78.2 96 6. 11.2 W68 record (L34) 2.78 2.78.3 96 W69 2.85 2.85.2 96 5 yr Storm (S5) 6.3 11.2 W7 2.85 2.85.3 96 W71 1 yr Storm (S1) 2.93 2.93 6.6 11.2.2 96 W72 2.93 2.93.3 96 Geomorphic Solutions 176 Stable Dynamic Beach Modelling Results 24

Table 1: Modelling Scenarios for Thunder Beach varying water level scenarios and wave characteristics (Elevations relative to Chart Datum: 176. m above IGLD85). Run # Storm Event Water Level (m, CD) Peak Surge Level (m) Thunder Beach WL + Peak Surge Level (m, CD) Peak H sig (m) Peak T p (s) Sediment Size D 5 (mm) T1 1 1.78.16 48 T2 1.1 1.1.16 48 T3 1.2 1.2.16 48 T4 1.3 1.3.16 48 T5 1.4 1.4.16 48 Largest in 34.9 yr Hindcast T6.78 5.7 1.8 record (L34) 1.5 1.5.16 48 T7 1.6 1.6.16 48 T8 1.7 1.7.16 48 T9 1.8 1.8.16 48 T1 1.9 1.9.16 48 T11 2 2.16 48 T12 1 1.85.16 48 T13 1.1 1.1.16 48 T14 1.2 1.2.16 48 T15 1.3 1.3.16 48 T16 1.4 1.4.16 48 T17 5 yr Storm (S5) 1.5.85 1.5 6.2 1.8.16 48 T18 1.6 1.6.16 48 T19 1.7 1.7.16 48 T2 1.8 1.8.16 48 T21 1.9 1.9.16 48 T22 2 2.16 48 T23 1 1.93.16 48 T24 1.1 1.1.16 48 T25 1.2 1.2.16 48 T26 1.3 1.3.16 48 T27 1.4 1.4.16 48 T28 1 yr Storm (S1) 1.5.93 1.5 6.4 1.8.16 48 T29 1.6 1.6.16 48 T3 1.7 1.7.16 48 T31 1.8 1.8.16 48 T32 1.9 1.9.16 48 T33 2 2.16 48 T34 1 1.78.16 96 T35 1.1 1.1.16 96 T36 1.2 1.2.16 96 T37 1.3 1.3.16 96 T38 1.4 1.4.16 96 Largest in 34.9 yr Hindcast T39.78 5.7 1.8 record (L34) 1.5 1.5.16 96 T4 1.6 1.6.16 96 T41 1.7 1.7.16 96 T42 1.8 1.8.16 96 T43 1.9 1.9.16 96 T44 2 2.16 96 T45 1 1.85.16 96 T46 1.1 1.1.16 96 T47 1.2 1.2.16 96 T48 1.3 1.3.16 96 T49 1.4 1.4.16 96 T5 5 yr Storm (S5) 1.5.85 1.5 6.2 1.8.16 96 T51 1.6 1.6.16 96 T52 1.7 1.7.16 96 T53 1.8 1.8.16 96 T54 1.9 1.9.16 96 T55 2 2.16 96 T56 1 1.93.16 96 T57 1.1 1.1.16 96 T58 1.2 1.2.16 96 T59 1.3 1.3.16 96 T6 1.4 1.4.16 96 T61 1 yr Storm (S1) 1.5.93 1.5 6.4 1.8.16 96 T62 1.6 1.6.16 96 T63 1.7 1.7.16 96 T64 1.8 1.8.16 96 T65 1.9 1.9.16 96 T66 2 2.16 96 T67 Largest in 34.9 yr Hindcast 2.78 2.78 5.7 1.8.1 96 T68 record (L34) 2 2.3 96 T69 2 2.85.1 96 5 yr Storm (S5).85 6.2 1.8 T7 2 2.3 96 T71 1 yr Storm (S1) 2.93 2.93 6.4 1.8.1 96 T72 2 2.93.3 96 Duration (hrs) Geomorphic Solutions 176 Stable Dynamic Beach Modelling Results 25

4. REFERENCES Baird, 21a. Coastal Zone Technical Working Group Study Site Selection Final Report. Prepared for the International Joint Commission, Coastal Zone Technical Working Group. Baird, 21b. Erosion Theme Final Report, Prepared for the International Joint Commission, Coastal Zone Technical Working Group. Baird, 21c. Upper Great Lakes Study Flooding Evaluation, Return Period Analysis for Alternative Regulation Plans, Draft Report Appendix C. Distributions of fit to independent variables. Prepared for the International Joint Commission, Coastal Zone Technical Working Group. Danard, M., Munro. A., Murty, T. 23. Storm Surge Hazard in Canada. Natural Hazards, 28: 43 431. Davidson-Arnott, R.G.D. 1977. Thunder Beach field notes, May 1977. Davidson-Arnott, R.G.D. and Pember, G.F. 198. Morphology and sedimentology of multiple parallel bar systems, southern Georgian Bay, Ontario. The Coastline of Canada, Geological Survey of Canada, 8 1: 417 428. Davidson- Arnott, R.G.D. 1981. Wasaga Beach paper # 2 field notes, June 1981. Geomorphic Solutions, 29. Scoping exercise to review available predictive models for cohesive and sandy shoreline erosion on the upper Great Lakes along with their associated uncertainties. Prepared for the International Joint Commission. Geomorphic Solutions, 21. Introduction to Stable Dynamic Beach Assessment, Final Report. Prepared for the International Joint Commission as part of the International Upper Great Lakes Study. Geomorphic Solutions, 211. Stable Dynamic Beach Modelling Results. Prepared for the International Joint Commission as part of the International Upper Great Lakes Study Houser, C. and Greenwood, B. 25a. Profile of a lacustrine multiple barred near shore to a sequence of storm events. Geomorphology, 69: 118 137. Houser, C. and Greenwood, B. 25b. Hydrodynamics and sediment transport within the inner surf zone of a lacustrine multiple-barred near shore. Marine Geology, 218: 37 63. Larson, M., Kraus, N.C. and Byrnes, M. 199. SBEACH: Numerical model for simulating storm-induced beach change. Report 2: Numerical formulation and model test. Technical Report CERC-89-9, U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal Engineering Research Center, Vicksburg, MS. Larson, M. 1992. Enhancement to a beach profile change model, Final Report. Prepared for The U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal Engineering Research Center, Vicksburg, MS. MNR, 1989. Great Lakes System Flood Levels and Water Related Hazards. Conservation Authorities and Water Management Branch. Ontario Ministry of Natural Resources. NOAA, 21a. GEODAS Bathymetric Grid Translator Great Lakes (gkey_123) National Ocean and Atmospheric Administration. [online] Available at URL: http://www.ngdc.noaa.gov/mgg/gdas/gd_designagrid.html [cited June 8 th, 21]. 26

NOAA, 21b. Recorded Monthly mean water levels for stations in the Great Lakes, provided to Environment Canada by Mr. John Herron. Philpotts, 1988. Wave hindcast dataset for Onatio s Great Lakes Lake Huron / Georgian Bay. Prepared for the Ministry of Natural Resources. Part 4, Georgian Bay Wave Statistics. Rosati, J. D., Wise, R. A., Kraus, N. C., and Larson, M. (1993). SBEACH: Numerical model for simulating storm-induced beach change; Report 3: User s Manual. Instruction Report CERC-93-2, U.S. Army Corps of Engineers, Waterways Experiment Station, Coastal Engineering Research Center, Vicksburg, MS. USACE, 21. Great Lakes, Wave Information Studies, Coastal and Hydraulics Laboratory. United States Army Corps of Engineers. [online] Available at URL: ftp://ftp.erdc.usace.army.mil/pub/perm/wisftp/greatlakes [cited May 26 th, 21] 27