ADAPTIVE MANAGEMENT STRATEGY Coping Zones

Transcription

1 ADAPTIVE MANAGEMENT STRATEGY Coping Zones IDENTIFYING VULNERABILITIES THROUGH THE DEVELOPMENT OF COPING ZONES SEPTEMBER 23, 2011 Prepared by: Daniel Ferreira Environment Canada Adaptive Management Group Support

2 TABLE OF CONTENTS 1.0 INTRODUCTION COPING ZONES DEVELOPMENT COPING ZONE DEFINITIONS COPING ZONES THRESHOLD DEFINITIONS ADDITIONAL FACTORS TECHNICAL WORKING GROUPS COPING ZONES COASTAL ZONE TECHNICAL WORKING GROUP (COASTAL TWG) COPING ZONES MUNICIPAL AND INDUSTRIAL WATER USES TECHNICAL WORKING GROUP (M&I TWG) COPING ZONES COMMERCIAL NAVIGATION TECHNICAL WORKING GROUP (COMMERCIAL NAVIGATION TWG) COPING ZONES RECREATIONAL BOATING & TOURISM TECHNICAL WORKING GROUP (REC. BOATING TWG) COPING ZONES HYDROPOWER TECHNICAL WORKING GROUP (HYDROPOWER TWG) COPING ZONES ECOSYSTEM TECHNICAL WORKING GROUP (ECOSYSTEM TWG) COPING ZONES COMMON VULNERABILITIES CONCLUSION REFERENCES LIST OF FIGURES Figure 1: Examples of how water level regimes (water levels, rate of change and duration) may cause interests to go into different coping zones. (The water levels and coping zones in this example or not representative of any interest)... 8 Figure 2: Glacial Isostatic Adjustment on the Great Lakes... 9 Figure 3: Coastal zone coping zones for Lake Superior (coping zone extents fluctuate monthly) plotted on historical water levels ( ) Figure 4: Coastal zone coping zones for Lake Michigan-Huron (coping zone extents fluctuate monthly) plotted on historical water levels ( ) Figure 5: Coastal zone coping zones for Lake St.Clair (coping zone extents fluctuate monthly) plotted on historical water levels ( ) Figure 6: Coastal zone coping zones for Lake Erie (coping zone extents fluctuate monthly) plotted on historical water levels ( ) Figure 7: M&I coping zones for Lake Superior plotted on historical water levels ( ) Figure 8: M&I coping zones for Lake Michigan-Huron plotted on historical water levels ( ) Figure 9: M&I coping zones for Lake St. Clair plotted on historical water levels ( ) Figure 10: M&I coping zones for Lake Erie plotted on historical water levels ( ) Figure 11: Commercial Navigation coping zones for Lake Superior plotted on historical water levels ( ).. 22 Figure 12: Commercial Navigation coping zones for Lake Superior Southwest Pier (St. Marys River) plotted on historical water levels ( ) Figure 13: Commercial Navigation coping zones for Lake Michigan-Huron plotted on historical water levels ( ) Figure 14: Commercial Navigation coping zones for Lake St. Clair plotted on historical water levels ( )... 24

3 Figure 15: Commercial Navigation coping zones for Lake Erie plotted on historical water levels Figure 16: Recreational Boating coping zones for Lake Superior plotted on historical water levels ( ) Figure 17: Boat Launch coping zones for Lake Superior plotted on historical water levels ( ) Figure 18: Recreational Boating coping zones for Lake Michigan-Huron plotted on historical water levels ( ) Figure 19: Boat launch coping zones for Lake Michigan-Huron plotted on historical water levels ( ) Figure 20: Recreational Boating coping zones for Lake Erie plotted on historical water levels ( ) Figure 21: Boat launch coping zones for Lake Erie plotted on historical water levels ( ) Figure 22: Coping Zone and Threshold Approach for Ecological Performance Indicators (adapted from ETWG 2009) Figure 23: Ecosystem coping zones for Lake Sturgeon on the St. Marys River (SMQ-01) plotted on historic water flows for the month of June ( ). Same water flow for zone B and C but zone B is 3 out of 5 years and zone C for 5 consecutive years Figure 24: Ecosystem coping zones for eastern Georgian Bay wetlands (LMH-07) plotted on historic water levels (Lake Michigan-Huron) for the months April to October ( ). Coping zone represents present conditions Figure 25: Ecosystem coping zones for eastern Georgian Bay wetlands (LMH-08) plotted on historic water levels (Lake Michigan-Huron) for the months April to October ( ). Coping zone accounts for GIA 50 years into the future TABLE OF CONTENTS Table 1: Coastal zone monthly water levels (metres) that represent the transition zones between coping zones for each lake Table 2: M&I water uses lake wide water levels that represent the transition zones between coping zones for each lake Table 3: Commercial Navigation Lake wide water levels that represent the transition zones between coping zones for each lake and St. Marys River Table 4: Recreational Boating Lake wide water levels that represent the transition zones between coping zones.. 32 Table 5: Hydropower coping zones table for the Cloverland Plant in the St. Marys River. Levels in metres, IGLD 1985, flows in m3/s (Hydropower Technical Working Group, 2011) Table 6: Hydropower coping zones table for the compensating works and Lake Superior outflow regulation. Levels in metres, IGLD 1985, flows in m3/s (Hydropower Technical Working Group, 2011) Table 7: Hydropower coping zones table for the Moses plant in the Niagara River. Levels in metres, IGLD 1985 flows in m3/s. Lake Erie outflow is the sum of Niagara River flow and Welland Canal diversion (Hydropower Technical Working Group, 2011) Table 8: Ecosystem coping zones for 6 priority performance indicators only Table 9: Coping Zones for Cloverland Plant in St. Marys River. Levels in meters IGLD 1985 and flows in m3/s Table 10: Coping Zones for United States Government Plant in St. Marys River. Levels in meters IGLD 1985 and flows in m3/s Table 11: Coping Zones for Brookfield Plant in St. Marys River. Levels in metres, IGLD 1985 and flows in m3/s

4 Table 12: Coping Zones for Compensating Works and Lake Superior Outflow Regulation. Levels in metres, IGLD 1985 and flows in m3/s Table 13: Coping Zones for Moses Plant in Niagara River. Levels in metres, IGLD 1985 and flows in m3/s. Lake Erie outflow is the sum of Niagara River flow and Welland Canal diversion Table 14: Coping Zones for Beck 1 and Beck 2 Plants in Niagara River. Levels in metres, IGLD 1985 and flows in m3/s. (1) On completion of the current Niagara tunnel project Table 15: Coping Zones for Chippawa-Grass Island Pool (CGIP) Control Structure in metres Table 16: Coping Zones for Moses and Saunders Plants in St. Lawrence River. Levels in metres, IGLD 1985 and flows in m3/s Table 17: Coping Zones for Beauharnois-Cedars Complex in St. Lawrence River. Levels in metres, IGLD 1985 and flows in m3/s Table 18: Coping Zones for DeCew Falls (ND1 and NF23) Plants. Levels in metres, IGLD 1985 and flows in m3/s, operating heads in metres Table 19: Coping Zones for St. Catharines Hydro (Heywood) Plant. Levels in metres, IGLD 1985, flows in m3/s and operating head in metres. Headwater is Martindale Pond and tailwater is Lake Ontario at the Port Weller gauge. 59 Table 20: Coping Zones for Units at Weirs 1, 2 and 3 of the Welland Canal Table 21: Coping zones for all the ecological performance indicators as identified by the Ecosystem TWG LIST OF PHOTOS Photo 1: Bluff erosion on Lake Michigan that damaged shoreline structures Photo 2: Flooding in the Wasaga Beach commercial district during a storm in Photo 3: Docks disconnected from the water in Goulais Bay, Lake Superior during low water levels in Photo 4: Dry dock located on an eastern Georgian Bay wetland in June APPENDICES Appendix A: Hydropower Coping Zone Tables Appendix B: Coping Zones Table for Ecological Performance Indicators

5 Identifying Vulnerabilities through the Development of Coping Zones September 23, Introduction A component of the Adaptive Management (AM) strategy is to define a series of coping zones for interests impacted by Great Lakes water levels. These coping zones will be used to identify the vulnerabilities interests may face due to problematic water supplies and climate change. This is a first step in a strategy to identify plausible future water level conditions under which stakeholders could not cope using existing policies and infrastructure and then to design a strategy for triggering policy changes and investments in time to address the changing water conditions. The AM strategy proposed is a bottom-up approach that begins with the system or decision and follows three steps: 1. Identify system/decision vulnerabilities to climate (problematic water supplies) 2. Characterize the plausibility of those climate hazards 3. Use systematic decision approach to address climate risks The objective of coping zones effort is to address the first step of the strategy to help identify key vulnerabilities and problematic water supplies and to explore strategies for minimizing risk. The six technical working groups (TWGs) representing different shoreline interests on the upper Great Lakes have been assigned to identify key areas where individuals, businesses, communities and organizations within their specific area of interest are vulnerable to lake level fluctuation including range (high and low), frequency, rate of change and duration. Using this information and methods unique to each TWG, each group developed a range of coping zones for their specific interest that assessed vulnerability to level fluctuations as well as confounding factors such as global isostatic adjustment, wind/waves/storm surges, precipitation patterns and the idiosyncrasies associated with specific locations. The six interests represented by the TWGS are the coastal zone (riparian property owners), municipal and industrial water uses, recreational boating and tourism, commercial navigation, hydropower and the ecosystem. The Study Board is examining whether a new plan for regulating Lake Superior outflows could help minimize future vulnerabilities, or if new control structures elsewhere in the Great Lakes could be an effective mechanism for minimizing or even eliminating the risk to exceeding coping zone thresholds. Coping mechanisms could also include policy or investment changes made outside of water level regulation. 5

6 Identifying Vulnerabilities through the Development of Coping Zones September 23, Coping Zones Development 2.1 Coping Zone Definitions The coping zones were broken down into three zones (A, B & C). The definitions for these coping zones provide a general context behind what each zone represents, however, theses definitions may be altered slightly by a TWG to accommodate the exclusiveness of their interests. Two sets of coping zones 1) socio-economic and 2) environmental are defined as followed: Socio-Economic Coping Zone Definitions Zone A: Levels which, if not ideal, are acceptable and within the tolerance and expectations of the interest. This may vary by interest and location, but levels are likely to be within the historical range, although, not likely at the extremes. Zone B: Outside an interest s expectations, yet they can cope under current management regimes. Interests make significant changes in their activities, forego long-standing benefits, or experience non-trivial costs, but almost all are able to sustain those costs without serious financial consequence such as bankruptcy. The impacts are generally not considered irreversible. Zone C: The zone of persistent negative consequences. Hazard zone policies and major infrastructure would be compromised. Interests are forced to make significant changes in their activities, forego long-standing benefits, or experience significant costs. A substantial number of firms and households face serious financial consequences such as bankruptcy. The impacts are considered irreversible. In some cases Zone C may result from extended persistence of Zone B conditions. Environmental Coping Zone Definitions Zone A: Ecosystems flourish within this zone and there is natural variability with respect to water level regime. Zone B: Environmental impacts would be measurable, there would be moderate changes to biotic community structure, but minimal changes to ecosystem function. The impacts are generally not considered irreversible. Zone C: There are moderate to major changes in the ecosystem function causing serious degradation of it and there would be major changes to biotic community structure. In most cases an extended period of zone B conditions may result in a zone C. 6

7 Identifying Vulnerabilities through the Development of Coping Zones September 23, Coping Zones Threshold Definitions A critical aspect in defining the coping zones is determining the thresholds that mark the transitions between zones. The TWGs determined the factors that can push their interest from one zone to another (E.g. zone A to B) and assess if they can recover should the levels return back to the ideal conditions. The transition thresholds from zone A to B and from zone B to C are defined as followed: Zone A to B transition threshold: The point at which stakeholders begin to experience significant damage or significant costs to avoid impacts that are considerably beyond their expectations. (e.g. ships must regularly light load or suffer delays, property owners suffer damage, build or re-build shore protection, extend their docks etc ) Zone B to C transition threshold: One way of identifying this transition threshold is the point at which stakeholder uses or major infrastructure fail (e.g. major shoreline infrastructures such as piers, shore protection and dykes fail, public marinas go out of business, water use operations are compromised, failure of dam operation etc ). Another way of identifying this transition threshold may be that an existing policy designed to protect stakeholders is no longer adequate (e.g. floodzone delineation is no longer credible or usable or the point at which homes are destroyed and cannot be rebuilt in the same location). 2.3 Additional Factors When defining the coping zones the TWGs were to consider water level regime, location and other factors that cause vulnerabilities for their respective interests. To determine the problematic water level regimes, TWGs were to consider: Water level range (i.e. highs, lows, averages) Rate of change of levels (i.e. how quickly the levels move from a high to a low) Frequency (i.e. how often water levels are high or low) Duration (i.e. the length of a high or low event) Seasonality (i.e. timing of the peaks) Figure 1 provides three examples of how water level regimes may put an interest in different coping zones. Example 1 shows that both extreme high and low water levels can bring interests into a zone B and C. Example 2 illustrates that although water levels are in a zone B, the rapid change from high water levels to low levels can push some interests into a zone C. A quick rate of change will not allow the necessary time for interests to adapt to the fluctuation and may push them into an early zone C although the actual water levels were not identified as a zone C. Example 3 displays that some interests can endure zone B water levels, however, if those conditions persist for an extended duration (e.g. 2 years) it may drive an interest into a zone C. Most interests can endure and recover from short term negative impacts associated with zone B conditions, but should these conditions persist for an extended period the impacts may eventually surpass what an interest can handle placing the interest in a zone C scenario (e.g. bankruptcy or shutting down). Alternatively, some interests may take action to adapt when within a zone b making them even less vulnerable to a zone c condition. 7

8 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 The Great Lakes is complex in nature and not all locations are affected equally. To account for location differences when developing coping zones, the TWGs have: Identified key differences on a fairly broad basis (At a minimum by lake, but more detailed scale if necessary); Highlighted very vulnerable areas; and Most of the TWGs have defined their coping zones on a lake wide scale and some have made their own variations (e.g. the hydropower TWG focused on the location of their hydropower plants and structures). Identifying particularly sensitive areas within each lake is important because assuring that the coping zones were developed to include these vulnerable areas makes the coping zones more robust. For example, low water levels will impact areas with shallow water such as harbors and bays more so than steep shorelines located on a portion of the open lake. Figure 1: Examples of how water level regimes (water levels, rate of change and duration) may cause interests to go into different coping zones. (The water levels and coping zones in this example or not representative of any interest) The TWGs were also to identify if there were any additional complicating factors that in combination with water level regimes and location could push their interest to a zone B or C. Some of these factors include: Glacial Isostatic Adjustment, wind/waves/storm surges, precipitation patterns, changes in ice cover, water/air temperature changes and other forcing events such as economic jolts or significant invasions of exotic species. 8

9 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Glacial Isostatic Adjustment (GIA) is a term used to describe the differential movement of the earth s surface following the last glaciation. On the Great Lakes, the movement of the shoreline on each lake is relative to the outlet of its respective lake. For example, in figure 2 the most northern point of Lake Superior is rising 28 cm/year relative to the lakes outlet (St. Marys River) and the most western point of Lake Superior is falling 25 cm/year relative to the outlet. Hypothetically, if water levels did not fluctuate, the water levels will still appear to be lowering at shorelines where the earth s crust is rising and the water levels will appear to be rising for shorelines where the earth s crust is sinking. Figure 2: Glacial Isostatic Adjustment on the Great Lakes A set of coping zones had to be created for each of the TWGs because there are some factors that may influence one interest more so than another. In addition different interests will have a greater ability to cope to certain water level conditions than others. For example high water levels with a storm surge can flood both residential dwellings and a public water supply facility. This example could damage the residential dwelling beyond repair putting it into a zone C; whereas the public water supply facility which cannot fail due to its significance to the community may have taken initiative to protect the facility or use some of the revenue to repair the damages thus resulting in a zone B scenario. The 9

10 Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 uniqueness of the different interests on the Upper Great Lakes is why separate coping zones had to be created for each group. 3.0 Technical Working Groups Coping Zones 3.1 Coastal Zone Technical Working Group (Coastal TWG) Coping Zones The coastal TWG provided expertise and information relating to the impacts of fluctuating water levels on coastal interests and processes. The high water impacts on coastal interests include erosion/recession, flooding, sustainability of shore protection structures, and low water impacts on public and private riparian property owners will cause beach use issues, difficulty accessing docks and complicate land-water accessibility. The coping zones were developed through determining which water levels will transition one zone to another (zone A to B & zone B to C) based on previously documented impacts experienced with historical water levels. To account for seasonality, the coastal TWG developed a set of coping zones for not only each lake, but for each month. Table 1 displays the monthly water levels representing each transition from coping zone A to B and B to C for each lake. Figures 3 6 are graphical representations of the coping zones (graphs do not account for duration) for each lake plotted with historical water levels from 1970 to (last 40 years) Zone C Zone B Zone A Historic Water Levels (m) Year Figure 3: Coastal zone coping zones for Lake Superior (coping zone extents fluctuate monthly) plotted on historical water levels ( ) 1 Only the last 40 years of historic water levels were plotted with the coastal coping zones. This is due to the wavy coping zones creating resolution issues for the entire historical plot from

11 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Year Figure 4: Coastal zone coping zones for Lake Michigan-Huron (coping zone extents fluctuate monthly) plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) Year Figure 5: Coastal zone coping zones for Lake St.Clair (coping zone extents fluctuate monthly) plotted on historical water levels ( ) 11

12 Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) 171 Year Figure 6: Coastal zone coping zones for Lake Erie (coping zone extents fluctuate monthly) plotted on historical water levels ( ) Lake Superior (Figure 3) Lake Michigan-Huron (Figure 4) Low Zone B-C Transition Low Zone A-B Transition High Zone A-B Transition High Zone B-C Transition Low Zone B-C Transition Low Zone A-B Transition High Zone A-B Transition High Zone B-C Transition January February March April May June July August September October November December

13 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Lake St. Clair (Figure 5) Lake Erie (Figure 6) Low Zone B-C Transition Low Zone A-B Transition High Zone A-B Transition High Zone B-C Transition Low Zone B-C Transition Low Zone A-B Transition High Zone A-B Transition High Zone B-C Transition January February March April May June July August September October November December Table 1: Coastal zone monthly water levels (metres) that represent the transition zones between coping zones for each lake The high water level transition from zone A to zone B is the average water level from the high water years but are generally below the peak levels in These levels were used because there were some coastal damages reported by Ontario Conservation Authorities during these high water years, however, not significant enough to be classified as zone C magnitude damages. These levels are the 10% exceedance level above the monthly averages and they also demonstrate that large storm events and wave energy conditions in the fall, winter and spring, can impact flooding, erosion and shore protection even though water levels are not at their annual peak (Shantz, 2011). The transition from a high water level zone B to zone C is the average of the 1985 and 1986 high water levels (by month) which are the record high monthly levels and because there are no other historic levels that can be compared to these levels, they are considered beyond expectation. There have been several reports indicating significant direct and indirect damages (zone C magnitude) to portions of the Canadian and U.S. shoreline infrastructure due to both high water levels and short-term storm surges in 1985 and 1986 and existing hazard policies were inefficient to prevent damages. DeCooke (1988) reports that within this period, damage estimates were approximately $285 million (1988 dollars) for the U.S. shoreline within the IUGLS Study area and over $100 million dollars (1988 dollars) was spent on public and private mitigation (e.g. installation of dikes) on the U.S. shoreline. Large short-term storms can push water levels above the levels and can surpass the 1% exceedance flood hazard elevation. Very large storms can cause water levels to peak beyond expectations and beyond current management zones (Shantz, 2011). The transition from a low water level zone A to zone B was identified as the 80% exceedance level (by month) on Lakes Michigan-Huron, St. Clair, and Erie, and the 90% exceedance level on Lake Superior. Within the last decade (2000s) there has been considerable public concern regarding low levels at sections of the Great Lakes and the exceedance levels selected for the zone A to zone B transition 13

14 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 captures most of the low water years in the past decade. Within these recent low water years there have been a high number of applications for dredging permits and other shoreline modifications by property owners, however, these costs have not reached the extent to cause people to move away (Shantz, 2011). The transition from a low water level zone B to zone C for Lakes Michigan-Huron, St. Clair and Erie were based on the average water levels from the low water period between July 1963 to June 1965 and Lake Superior s transition from a low zone B to zone C were based from record low levels. The levels from July 1963 to July 1965 are not the record low water levels for the lakes mentioned, however, they are the most recent low water levels that can adequately represent current development conditions. These low levels can still be considered beyond expectation because there are very little comparable water levels to these within the historic record (Shantz, 2011). There is no documentation on quantitative assessments on the impacts caused by record low water conditions, and these proposed levels may be conservative (too high). For example figure 3 shows that Lake Superior water levels set record lows for the months of August and September in 2007 which match the zone B to C transition, while there have been negative impacts on riparians (especially on Goulais and Batchawana Bays) there is little evidence to demonstrate whether the coastal zone interest has fundamentally changed as a result of such conditions (Shantz, 2011). Water levels were the main driver in the creation of the coping zones for coastal interests; however, the coping zones often require other complicating factors in addition to water levels to cause significant coastal damages. Some other complicating factors include, duration, rate of change, shoreline profiles, GIA, changes in precipitation patterns and changes in lake ice coverage. Water levels may gradually increase or decrease into the zone C range (both high and low) and retreat back to manageable conditions causing minimal damage, however, the duration of these problematic water levels are as significant as the levels themselves. Water levels under zone B may be tolerable and have minimal impacts and can be considered a zone A for short-term periods, however, the cumulative impacts after two consecutive years of these conditions will push the interest into a zone B scenario. Extended low water periods will increase the need for dredging, dock modifications and beach grooming and users will experience accessibility issues (land to water) but the degree of these impacts are tolerable. Prolonged high water levels will increase the chances of coinciding with storm surges which will lead to moderate to substantial flooding, erosion and infrastructure damage. Water levels in the zone C range are also tolerable short-term, however, one year in these conditions will lead to substantial damages similar to those of zone B; however, the damages are beyond what coastal interests are able to cope with. Under these zone C conditions the costs to mitigate would exceed what would be manageable and/or there is permanent loss of some shoreline uses and functions. A rapid rate of change in water levels as discussed in example 2 in figure 1 (above) may also lead to significant shoreline damages putting an interest in an early zone B or C situation as the rapid change would make it difficult for stakeholders to undertake the necessary actions to adapt to the changes. 14

15 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 The shoreline profile can determine how vulnerable shoreline reaches are to zone B and C magnitude impacts. Reaches with unprotected cohesive bluffs are more susceptible to erosion which is enhanced by high water levels. These unprotected cohesive bluffs are most common but not limited to the southern/eastern shorelines of Lake Michigan-Huron as seen in photo 1 and Lake Erie. Increasing water levels (especially after prolonged period of low water levels) will increase short-term bluff recession rates, however, the rates may eventually return to values close to the long-term average even if high water levels are maintained for a number of years, but it also depends on additional factors such as bluff characteristics and wave conditions (Shantz, 2011). In addition to high water levels, wave action from large storm events will also increase short-term erosion rates that can lead to infrastructure failure even with water levels in a zone A. Photo 1: Bluff erosion on Lake Michigan that damaged shoreline structures GIA must be taken into account when determining plausible vulnerabilities to future fluctuating water levels. Areas where the earth s crust is subsiding such as the western end of Lake Superior (Duluth ~25 cm/century as observed in figure 2) will be more susceptible to high water impacts such as flooding as opposed to an area where the earth s crust is rising such as the eastern portion of Georgian Bay (Parry Sound ~24.3 cm/century). On the other hand the portions of shoreline rising are more susceptible to low water impacts (e.g. require dredging to access docks) than those areas with the earth s crust subsiding. When water levels are high and in a zone B or C range, precipitation patterns and changes in ice cover can also play a role in increasing shoreline damages. An increase in precipitation within the Great Lakes could cause inland flooding issues on river mouths due to backwater effects. A reduction in lake ice cover exposes open water to severe winter storms increasing the vulnerability of shorelines to wave action that can cause flooding in low laying areas and boost recession rates in regions with high cohesive 15

16 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 bluffs. A stable ice cover over large portions of the lakes can limit wave generation during severe storm events. Areas most vulnerable to high water impacts are usually developed shorelines located on low-lying, gently sloped shores and/or shorelines with cohesive bluffs. During the high water periods of and 1997 (figures 4-6) there were some reports of damage on shorelines with those characteristics. After a couple of storm events in December 1986 Wasaga Beach (see photo 2) on the south shore of Georgian Bay experienced flooding in the commercial district and some other areas of the beach faced erosion and shore protection damage at an estimated cost of $3 million (Shantz, 2011). The Chicago area on Lake Michigan encountered damage to lakeshore condominiums, cracked foundations, flooded basements and windows smashed by ice chunks from crashing waves due to a winter storm in 1986 (Malcolm, 1986). The high water levels in 1997 caused the erosion of high bluff areas near Port Stanley on Lake Erie which lead to a loss of agricultural land (Shantz, 2011). Coastal interests most vulnerable to low water impacts are those located within areas of shallow water such as bays and harbours. Photo 2: Flooding in the Wasaga Beach commercial district during a storm in 1986 Low water in recent years created accessibility issue in the Collingwood area in southern Georgian Bay. There are indications that the low water levels in recent years have led to numerous dredging applications for individual docks to accommodate the conditions (Shantz, 2011). In 2007, residential property owners on Goulais Bay and Batchawana Bay located in southeastern Lake Superior became susceptible to low water impacts as the water line migrated away from existing infrastructure (e.g. docks) as seen in photo 3 (Shantz, 2011). 16

17 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Photo 3: Docks disconnected from the water in Goulais Bay, Lake Superior during low water levels in 2007 To avoid impacts to the magnitude of zone B & C, coastal interest can take adaptive actions to accommodate both high and low water levels. Adaptive actions to accommodate high water levels include: shore protection, building modifications (including relocations), moving roads and repurposing the shoreline (temporarily for zone B) and adaptive actions to avoid low water impacts include: dock modifications, dredging, beach grooming, shore protection and relocation (Shantz, 2011). 3.2 Municipal and Industrial Water Uses Technical Working Group (M&I TWG) Coping Zones The M&I TWG identified and characterized potential operational problems of municipal, industrial and domestic water uses associated with fluctuations in water levels and flow rates (Bartz, Inch & Salisbury, 2010). Some impacts associated with high water levels include flooding, erosion and shore protection issues (similar to the coastal interests), inundation of plants and increased operating costs. Impacts associated with low water levels include water intake pipe exposure, increased water quality problems and potential water supply problems. The development of the coping zones was derived from interviews and surveys from facility operators and historical records. Historically water levels have not caused intakes for facility operations to fail; therefore there is a low degree of confidence in the coping zone B to C transition (Bartz, Inch & Salisbury, 2010). The coping zones were developed on a lake wide scale, in other words there are one set of coping zones for each upper Great Lake. Table 2 below has zone A to zone B and zone B to zone C transition water levels for each lake and figures 7 to 10 are graphical representations of the coping zones (graphs do not account for duration) plotted with the historical water levels from 1918 to

18 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Figure 7: M&I coping zones for Lake Superior plotted on historical water levels ( ) Year Zone C Zone B Zone A Historic Water Levels (m) Figure 8: M&I coping zones for Lake Michigan-Huron plotted on historical water levels ( ) Year 18

19 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Year Figure 9: M&I coping zones for Lake St. Clair plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) 171 Year Figure 10: M&I coping zones for Lake Erie plotted on historical water levels ( ) 19

20 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Lake Superior (Figure 7) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) Zone B to C High water level Zone A to B Low water level Zone A to B Zone B to C Lake Michigan-Huron (Figure 8) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Zone B to C Lake St. Clair (Figure 9) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Zone B to C Lake Erie (Figure 10) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Zone B to C Table 2: M&I water uses lake wide water levels that represent the transition zones between coping zones for each lake The water levels in coping zone B for both high and low levels for Lake Superior are the levels where operational problems begin but before the first facility operation ceases. The Lake Michigan-Huron coping zone B range was generally derived from the max and min historical records with the exception of some historical extremes that are considered beyond expectation. The zone B for Lakes St. Clair and Erie fall outside of the historic monthly averages range. The zone C water levels for all the lakes are beyond the historic range but at an elevation where it is expected that operations would begin to cease. Water levels are significant to facility operations; however, other factors in combination with problematic water levels are what essentially drive this interest into a zone B or C. Facilities can generally tolerate zone B water levels for short term durations, but, should the levels remain in a zone B for weeks or months it is expected to cause operational issues. Zone C water levels might also be tolerated by water use facilities for short term (12 to 24 hours) durations. Should the levels persist for days/weeks/months facilities will experience signification operational issues which will require capital changes or the facilities would have to shut down. A quick rate of change from ideal conditions to a 20

21 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 zone B or C will increase the chances of a disruption in facility operations because facility operators will have little time to adapt to the changes. Storm surges could cause an earlier entry into zones B and C depending on the frequency and magnitude of the storms. Facilities can cope with storm surges when water levels are in a zone B range for a short duration (12 to 24 hours), however, frequent storm surges when water levels are within the zone C range can cause substantial damages to facilities. Facilities in the Chicago area, within bays (E.g. Georgian Bay), and in the western and eastern points of Lake Erie are most susceptible to experience short-term operational problems due to storm surges. Water use facilities are particularly vulnerable to experience operational difficulties in the winter when temperatures are around freezing and might cause frazil ice to appear near intake pipes. Frazil ice can lead to operation difficulties for water withdrawal operations especially for facilities located the shores of Lake Erie. Operational issues are also more common during the seasonal low period in the winter months as the low water may cause issues at some intakes. During low levels, all the lakes will be vulnerable to having intake pipes and cribs exposed causing water withdrawal difficulties and it may also require marking for ships to avoid hitting the pipes and cribs. On Lake Superior and Lake Michigan-Huron intakes located within bays, areas of shallow water or near the shore are the most vulnerable. Due to the shallow depth of Lake St. Clair all intakes on this Lake are susceptible to impacts. Facilities on the western basin of Lake Erie are also susceptible to low water impacts due to the limited depth of the intakes and seiches. GIA may enhance high and low water level damages on facilities depending on the location. In combination with high water levels, facilities on shorelines that are sinking (see figure 2 for locations) may be more susceptible to flooding, erosion and structural damage than areas that are rising. Although facilities located on rising shorelines are less susceptible to high water level impacts they are more vulnerable to intake exposure and other operational issues during low water level periods. When water levels are either in a zone B, C or approaching problematic levels facilities can take adaptive actions to accommodate these water levels. The most common adaptive actions under zone B levels are operational changes, dredging of channels leading into intakes and power plants having to reduce their output. Adaptive actions under a zone C water regime will require capital changes and planning for extremes such as capital improvements that can be incorporated into major rehab projects. When low water levels are in the zone C range adaptive actions would involve changes to intake pipes or pumps (E.g. extend them into the lake or reduce its height) where as adaptive actions when high water levels are in the zone C range include building levees, floodproofing or relocation. Overall facilities are generally resilient and can cope with zone B levels with operational changes or maintenance; however, facilities such as public water systems cannot fail and must make capital improvements to avoid zone C magnitude damages. 21

22 Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Commercial Navigation Technical Working Group (Commercial Navigation TWG) Coping Zones The Commercial Navigation TWG examined the impacts fluctuating water levels will have on water depths throughout the upper Great Lakes since vessels depend on these depths. Restricted depths will limit a vessel s cargo capacities thus raising the cost to move a given amount of cargo (Millerd, 2009). In general, both high and low water levels will have an impact on the shipping industry; however, low water levels will have greater impact. Low water levels will reduce the underkeel clearance of vessels forcing them to carry lighter loads and lose revenue. Ports and docks will have to dredge or modify their facilities to accommodate low levels. High water levels can flood ports, make locks unusable, damage structures, interrupt bridge clearances and increase the flows of rivers making navigation more difficult. The coping zones were created through delineating the ideal conditions for the shipping industry (zone A) and which water levels impacts would begin to arise. The coping zones were developed on a lake wide scale (one set of coping zones for each upper great lake) and the southwest pier of Lake Superior (St. Marys River). Table 3 displays the water levels that indicate the transition from a zone A to zone B and from a zone B to a zone C and figures 11 to 15 provide a graphical representation of the coping zones (graphs do not account for duration) plotted on historical water levels from Zone C Zone B Zone A Historic Water Levels (m) Year Figure 11: Commercial Navigation coping zones for Lake Superior plotted on historical water levels ( ) 22

23 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Year Figure 12: Commercial Navigation coping zones for Lake Superior Southwest Pier (St. Marys River) plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) 174 Year Figure 13: Commercial Navigation coping zones for Lake Michigan-Huron plotted on historical water levels ( ) 23

24 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Year Figure 14: Commercial Navigation coping zones for Lake St. Clair plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) 171 Year Figure 15: Commercial Navigation coping zones for Lake Erie plotted on historical water levels 24

25 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Lake Superior (Figure 12) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Lake Superior - St. Mary's River - Southwest Pier (Figure 13) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Not provided Not provided Zone B to C Not provided Not provided Lake Michigan-Huron (Figure 14) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Zone B to C Lake St. Clair (Figure 15) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Not provided Not provided Zone A to B Not provided Not provided Zone A to B Zone B to C Lake Erie (Figure 16) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Table 3: Commercial Navigation Lake wide water levels that represent the transition zones between coping zones for each lake and St. Marys River The high water level zone A to B transition marks the levels required to maintain a one foot clearance at most ports and docks within each lake. For example, if water levels rise to a point where there is less than a one foot height clearance at a port or dock it would be classified as a zone B because there would be some constraints, however, the facilities can still operate. The high water levels that represent the zone B to C transition are the levels at which many docks and ports are flooded (zero height clearance) and unable to operate. In Lake Superior and St. Marys River zone C water levels would reach the top of the gates at the Soo Locks making it inoperable and interrupting navigation (Moulton & Wright, 2011). 25

26 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 The low water levels that mark the zone A to B transition are the levels which vessel operations suffer negative impacts such as reducing cargo to accommodate the depth clearance reductions therefore increasing the costs of shipping. Vessel operators can cope with these impacts and commodities are still being transported. In many cases the additional costs are passed onto their customers. The zone B to C transition for low water conditions will impact operators to a point where the costs will exceed what the customer is willing to pay, forcing the customers to find another mode of transportation and can lead the operators to bankruptcy. Water levels (especially low water levels) have serious implications on the shipping industry, however, other factors (E.g. long duration) in addition to problematic water levels also play a role in the magnitude of impacts. As previously mentioned, vessel operators can generally cope with problematic water levels in the zone B range by lightening loads and passing the costs to customers, however, should these conditions persist for extended periods (E.g. 2-3 years) the costs will exceed what customers are willing to pay and they will begin to find other modes of transportation (Moulton & Wright, 2011). During low level periods, wind, waves and storms may enhance shipping disruptions already caused by low levels. Sustained high winds can push water levels up on one end of the lake and cause it to drop on another end of the lake and form seiches. Seiches may restrict travel into shallow waters (I.e. Bay s and Harbours) and the passage will have to wait until the wind or storm subsides (Moulton & Wright, 2011). Winter storms can cause superstructure icing on a vessel which affects its stability (Moulton & Wright, 2011). Spring and summer storms are also dangerous to vessels and they may be forced to take shelter prolonging the voyage (Moulton & Wright, 2011). The disruptions caused by storms are normally short term, but, these disruptions when conditions are already unfavourable will only increase the hardship on vessel operators. Lake ice cover generally restricts navigation and making it more difficult in the winter. Navigation is impeded when ice formed at the shores (typically beginning in November) breaks off becoming floes and fields which in combination with wind action form pressure ridges and windrows (Moulton & Wright, 2011). Navigation is also restricted when locks close for the winter. Locks are generally closed for over 2 months in the winter (December March) because ice makes the locks difficult to operate and shut down time is required for maintenance. These seasonal closures are expected, but, a reduction of lake ice coverage would prolong the navigation season and would be beneficial to vessel operators. If water levels during the navigation season are low and in a zone B or C range, a pro-longed season (extended into the winter) due to lack of ice cover may help mitigate some of the losses caused by the low water. GIA will exacerbate impacts caused by low water levels or perhaps improve conditions depending on the location of the port. Ports located on shores that are sinking such as Duluth (western Lake Superior) will be more accessible because the water depth will increase in the future. Ports located on rising shores (north shore of Lake Michigan and eastern and southern Georgian Bay) will further have reduced depths in the future impeding access to these ports. GIA can also influence the coping zone range in the future. 26

27 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Water levels deemed as ideal may shift into a zone B range in the future for areas most influenced by GIA. Areas most susceptible to reduced depths are shallow bays, harbours, rivers and connecting channels. The water depths at these vulnerable areas must be considered when planning a voyage as the vessel cargo can only be loaded to accommodate the shallowest depth in the voyage. The St. Marys River, especially the Rock Cut location in the West Neebish Channel is a constraining location for many ship movements (Moulton & Wright, 2011). Commercial navigation has historically been resilient to fluctuating water levels through taking adaptive actions to accommodate for changes. Adaptive actions that can be taken to accommodate for future water level changes include regulation of water flows, dredging of harbours and channels, rebuilding of docks and loading and unloading facilities, revision of vessel operating procedures and building new vessels (Moulton & Wright, 2011). Vessels may also reduce their loads to accommodate reduced depths. A typical seaway-sized self-unloading vessel must reduce its load by 130 tonnes for every inch reduction in water depth (Moulton & Wright, 2011). Some additional adaptive actions can be considered during the planning phase of the voyage such as arranging smaller vessels to use shallower ports and larger vessels would use deeper ports also shallower ports should be more utilized during the seasonal high period. 3.4 Recreational Boating & Tourism Technical Working Group (Rec. Boating TWG) Coping Zones The Rec. Boating TWG have identified coastal tourism, Great Lakes cruising, marinas and boat launches as the sectors most likely to be impacted by fluctuating water levels. Both high and low water levels will have an impact on the boating industry. High water level impacts include flooding, erosion and infrastructure damage to marinas and boat launch facilities and low water levels will cause accessibility issues to marinas and boat launch facilities. The Rec. Boating TWG developed coping zones for both recreational boating practices (primarily marinas) and boat launch facilities on selected locations on the upper Great Lakes that best represent their respective lake. For Lake Superior marina s and boat launch facilities in Thunder Bay, Baraga and Ontanagon were examined. Coping zones for both marinas and boat launches were developed for two sets of locations on Lake Michigan-Huron, 1) Port Huron, Parry Sound, Bay City, Menominee, Holland and Richard s Landing and 2) Goderich, Midland, Little Current and Alpena. For Lake Erie coping zones were developed based on marinas and boat launch facilities located on Port Colborne, Turkey Point, Toledo/Sanduski & Kingsville. No marinas or boat launch facilities were examined for Lake St. Clair. Table 4 displays the water levels that mark the transition between zone A to zone B and from zone B to zone C. Figures 16 to 21 are a graphical representation of the coping zones (graphs do not account for duration) plotted with historical water levels from 1918 to 2009 for both recreational boating (primarily coping zones for marinas) and boat launch facilities. The first set of locations on Lake Michigan-Huron listed above were selected to represent the coping zones for the lake in figure 18 because the coping zones for those sites are more sensitive than the coping zones for the second set of sites. 27

28 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Year Figure 16: Recreational Boating coping zones for Lake Superior plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) Year Figure 17: Boat Launch coping zones for Lake Superior plotted on historical water levels ( ) 28

29 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) Year Figure 18: Recreational Boating coping zones for Lake Michigan-Huron plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) Year Figure 19: Boat launch coping zones for Lake Michigan-Huron plotted on historical water levels ( ) 29

30 Historic Water Level (m) Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone C Zone B Zone A Historic Water Levels (m) 171 Year Figure 20: Recreational Boating coping zones for Lake Erie plotted on historical water levels ( ) Zone C Zone B Zone A Historic Water Levels (m) 171 Year Figure 21: Boat launch coping zones for Lake Erie plotted on historical water levels ( ) 30

31 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Lake Superior (Thunder Bay, Baraga, Ontanagon) (Figure 17) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Lake Superior (Boat Launch) (Figure 18) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Lake Michigan - Huron (Port Huron, Parry Sound, Bay City, Menominee, Holland and Richard's Landing) (Figure 19) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Lake Huron (Goderich, Midland, Little Current and Alpina AOS) (Not plotted as Lake Michigan-Huron is represented with figure 19) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Lake Michigan - Huron (Boat Launch) (Figure 20) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Zone B to C Lake Erie (Port Colborne, Turkey Point, Toledo/Sanduski & Kingsville AOS) (Figure 21) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Low water level Zone B to C Zone A to B Zone A to B Zone B to C

32 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Lake Erie (Boat Launch) (Figure 22) Coping Zones Transition Thresholds Water Levels (m) Water Levels (ft) High water level Zone B to C Zone A to B Zone A to B Low water level Zone B to C Table 4: Recreational Boating Lake wide water levels that represent the transition zones between coping zones. The coping zones were derived from identifying which water levels are problematic for marina owners based on information gathered from interviews and surveys. The two entities used to develop the coping zones were percentage of slip loss and percentage of marina s that would go out of business within a region. Zone A water levels are optimal with no marina s going out of business and less than 5% of slips would become unusable due to water levels. Water levels that would cause 10% to 30% slip loss and up to 30% of marina s to go out of business were used to frame zone B. Zone C was classified as water levels that would generate over 30% slip loss and over 30% of marinas to go out of business (Boick & Warren, 2011). Although figures display the historical water levels for entire years the boating community is more concerned with water levels in the typical boating season between April to October (generally the period of annual highs). No coping zones were created for the tourism and cruising sector as the Rec. Boating TWG provided the following explanation: Based on the 2010 Tourism study commissioned by the Study Board, the lake levels have little to no impact. For tourist businesses, the lake levels were not a significant factor influencing their customers on whether they visited their establishments. For tourists, the lake levels had minimal impact on their decision. No Coping Zones could be established using the data gathered from the research. (Boick & Warren, 2010) Marina s in the study areas of Lake Superior can generally withstand the zone B range with minimal damage, however, it is unknown how long marina s could cope with zone C water levels in this region before they succumb to going out of business. The marinas located on the Lake Michigan-Huron sites would be able to survive zone B conditions throughout a season, but, are more susceptible to impacts during the spring launch and fall haul-out. Many marinas in these regions on Lake Michigan-Huron would not be able to survive through a season of zone C conditions especially during the spring launch and fall haul-out and several marinas would struggle to survive should these conditions persist beyond a season. The marinas in the Lake Erie sites could have up to 30% of marinas go out of business during prolonged zone B water levels; however, over 30% of marinas would go out of business during prolonged zone C water levels. Zone B conditions would pose a problem for boat launch areas in this region for the first two years of these conditions or until actions are taken to adapt. Similar to other interests, a rapid rate of change into challenging water levels could push marinas into an early zone B or C entry because they would have little time to adjust. A rapid water level change could be welcomed if water levels are rapidly returning to favourable levels after being in a zone B or C range. 32

33 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 During the boating season, the impacts caused by low water levels in a zone B or C range on marinas and boat launches are enhanced in the fall and spring when the water levels are lower than the summer. The boating season is generally from April to October and the annual low period in the winter is not as concerning for operation, however, marinas and boat launch structures are vulnerable to severe winter storms. Both high and low zone B or C water levels in the winter are problematic for marinas and boat launches as it in combination with storm surges could cause significant undercutting to existing shoreline infrastructure during low water levels and flooding and ice damage during high levels (Boick & Warren, 2011). The configuration of Lake Erie makes recreational boating facilities on it especially susceptible to seiches, wind and storms all year round and marinas and boat launch facilities on this lake are also vulnerable to those effects. Similar to other TWGs GIA will enhance low water impacts on facilities located on rising areas and it will enhance high water impacts on facilities located on areas that are sinking. GIA may cause water levels currently classified as a specific coping zone to change in the future. Some locations in Lake Michigan-Huron where interests are most vulnerable to suffer impacts from zone B and C conditions are at the Honey Harbour and Richard s Landing access channels, areas with bedrock in the basins, the Trent-Severn outlet, Wasaga Beach, Spanish, Little Current and Port Huron (Boick & Warren, 2011). Marinas and sport fishing interests at Long Point Bay on Lake Erie are sensitive to low water impacts at the inner bay. As previously mentioned facilities located on Lake Erie during high level periods are vulnerable to flooding and ice damage caused by storms and seiches. Boat launches throughout the lakes located near high clay bluffs are prone to erosion and boat launches located at river mouths are vulnerable to both flooding during high water periods and accessibility issues during low water periods (Boick & Warren, 2011). Marina owners on Lake Michigan-Huron and Erie are likely to make some adaptations such as dock modifications or new walkways when water levels are in a zone B. During zone C water levels marina operators must take greater actions such as dredging, however many operators would just go out of business instead of investing further money into adaptive actions (Boick & Warren, 2011). The type of adaptive actions that boat launch zones would take to combat hazardous water levels were not identified, however, the property owners are expected to take action to protect their investment. Marinas and boat launch facilities on Lake Superior are generally resilient and only require minimal adaptive actions to recover. 3.5 Hydropower Technical Working Group (Hydropower TWG) Coping Zones The Hydropower TWG identified the implications of fluctuating water levels and flows on hydropower generation plants on the Great Lakes St. Lawrence River system. The impacts on hydropower operations can be caused by not only reduction in water supply or lack of water, but also high water level and flow episodes that are expected to occur from time to time even under a climate change regime (Rose & Yee, 2011). High water levels and flows will lead to spillage of excess water that could 33

34 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 have been used for power generation; it can cause operational issues and structural damage. Low water levels will reduce the amount of energy output leading to a loss in revenue and energy to the grid. The TWG provided coping zone definitions that are specific to the hydropower interest but with the same concepts as the original definitions. Zone A - levels and flows for generally trouble-free operations up to maximum power generation given its installed capacity. Zone B levels and flows would decrease energy generation and operating difficulties may start to occur. Zone C levels and flows would cause a plant to shut down due to lack of water or cause permanent structural damage that is beyond its ability to recover. An example of zone C impacts would be a plant having to shut down for an extended period due to lack of water or permanent structural damage that are beyond its ability to recover, or structural failure leading to the inability to regulate Lake Superior or Lake Ontario outflows for a long period of time (Rose & Yee, 2011). The hydropower TWG concluded that based on the guidelines in the coping zones definitions they would develop a new category known as low C (not necessary a zone C for low water levels). Undesirable scenarios that do not lead to bankruptcy or irreversible damages will be classified as either a zone B or a low zone C depending on the magnitude and duration of the impacts (Rose & Yee, 2011). The information used to compile these coping zones was collected from literature reviews and surveys completed by hydropower operators who identified problematic water levels and flows. The development of the coping zones for hydropower interests varies from the other previously mentioned interests. Instead of lake wide water levels, the hydropower TWG focused on both water flow and water levels and developed 12 sets of coping zones for each hydropower plant and control structure on the upper Great Lakes, they include: The Cloverland Plant, U.S. Government Plant, Brookfield Plant and the Compensating Works on the St. Marys River; The Moses Plant, Beck 1 and 2 Plants and the Chippawa-Grass Island Pool on the Niagara River; The DeCew Falls (ND1 and NF23) Plants, St. Catherines Hydro (Heywood) Plant and the Units at Weirs 1, 2 and 3 on the Welland Canal; and the Moses Plant, Saunders Plant and the Beauhanois-Cedars Complex on the St. Lawrence River. The coping zones developed are complex and must also consider flow allocations to other hydro plants, the compensating works on the St. Marys River and the falls on the Niagara River. Due to the complexity of the coping zones no graphs were created, but, the Hydropower TWG produced a table for each of the 12 coping zones that present different scenarios that constitute a zone A, B, low C & C. Three of the 12 coping zones tables are discussed in this report and the remaining nine tables can be found in Appendix A with the implications of each scenario discussed in the comments column. The three coping zones discussed in this report are the Cloverland Plant on the St. Marys River, the Compensating Works also on the St. Marys River and the Moses Plant on the Niagara River. Table 5 below shows the coping zones for the Cloverland plant on the St. Marys River displaying which outflows, water levels and water allocations to other plants that are problematic for the Cloverland plant. An example of a zone C situation for the Cloverland plant would require Lake Superior outflows 34

35 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 to be below 904 m3/s, Lake Superior levels at m with all of the outflows being allocated for the other two plants (US plant and Brookfield plant) and the remaining amount going for other purposes. A zone C for this plant is mathematically possible but it is not necessarily plausible because if outflows declined to this level arrangements would be made with the other plants to allocate some of their water to the Cloverland plant for heating and minimum market purposes (Rose & Yee, 2011). A minimum tailrace of m at the U.S. slip is required to keep water levels 6 centimeters above the draft tubes and anything below that level would be considered a low zone C as it can cause cavitation damage and energy loss. This scenario happened during the low water period in January/February 2007 (Rose & Yee, 2011). Zone A ideal A ideal L Superior Outflows A 2036~240 9 A/B B L Superior Levels Others, m 3 /s Cloverland capacity 850 US Plant capacity 405 Brookfield capacity 1140 Comments Equal share of available hydro water without spills Equal share of available hydro water without spills. Below 1236 Below ~ ~ ~1140 Adequate water for peaking operations (Cloverland IS curve) Limited to winter. Cloverland and US Plant minimum for ice management and heating. US Plant lockage needs 40 m 3 /s minimum Limited to winter. Assuming US Plant not requiring water for ice management, lockage and heating. B Overtopping bulkheads causing water onto generator floor. B High B B/low C Below 1526 Above 1084 Max Tailrace m at U.S. Slip minimum minimum Maintain level below the top of tailrace tunnel to avoid water in generator pits Limited to winter. 311 m 3 /s minimum for ice management and heating m 3 /s minimum for energy market. B/low C C Below 904 Min Tailrace m at US Slip To prevent cavitation damage causing loss of generation Cloverland Zone C situation due to zero water allocation. 35

36 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Table 5: Hydropower coping zones table for the Cloverland Plant in the St. Marys River. Levels in metres, IGLD 1985, flows in m 3 /s (Hydropower Technical Working Group, 2011) Zone The compensating works was created to offset compensate for the increased flow on the St. Marys River due to hydropower diversion. It also helps maintain water level depth for commercial navigation upstream into the locks. The inability to operate the gates of this structure could impact outflow regulation, navigation, hydropower operations and ice management (Rose & Yee, 2011). Table 6 provides the water flows and levels, headwater, number of opened gates and channel capacity scenarios that comprise the coping zones for the compensating works. In general, the compensating works are more vulnerable to high water levels and outflows as it can overtop the gates threatening structural integrity of the structure and will have to release surplus water which could have been used for energy generation. Further details on the compensating works can be found in the Coping Zones of Hydropower Operations in the Great Lakes St. Lawrence River System prepared by Rose and Yee (2011) of the Hydropower Technical Working Group. L Superior Outflows A 2,430 Maximum L Superior Levels A/B ~ monthly mean A/B A/B A/B 3,000 and higher Not to exceed at US Slip Not to exceed Headwater Gates Opening Frequent Changes Side channel 2,330 m 3 /s capacity Comments 2330 All three plants operating close to capacity and hydraulic conditions permitting. Regulation range, Criterion a, 1979 Order. Criterion b, 1979 Order, pre-project outflow if needed to reduce risk of flooding. Condition 1 of 1979 Order. May require maximum flow at plants and 16 gates opened at compensating works. Increasing hydropower production, gate open operational costs. A/B 4010 All gates Estimated maximum summer river flow capacity. A/B A/B 2,410 Winter Maximum When below Criterion C 1979 Order, pre-project outflow if needed to guard against unduly low L Superior. Reduce risk of river ice jams. Higher outflows have occurred when weather and ice conditions permitted, e.g., 3,170 m 3 /s in Dec This limit currently under review. B m All gates Recorded for month of November m (1) Maximum B/low C at SW Pier Maximum Operational constraint: overtopping the gates and associated supports pose serious threat to structural integrity of 36

37 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Zone L Superior Outflows L Superior Levels B Maximum B/ low C, and C Headwater Gates Opening Side channel 2,330 m 3 /s capacity Comments the compensating works Task Force report: Maximum allowable. Partial dam structural failure, repairs taking months to several years, due to overtopping, ice, storm, or their combinations. Total failure would be a Coping Zone C situation as new construction would take several years. Table 6: Hydropower coping zones table for the compensating works and Lake Superior outflow regulation. Levels in metres, IGLD 1985, flows in m 3 /s (Hydropower Technical Working Group, 2011) Table 7 displays the coping zone scenarios for the Moses Plant (NYPA) on the Niagara River accounting for outflows and water levels for Lake Erie, the flows of the Niagara River and the water allocations for both the New York Power Authority and Ontario Power Generation plants. An example of a zone B for high water levels is the Niagara River flow exceeding 7020 m3/s which will result in an increase of spillage over the Niagara Falls, foregoing the energy generation that could have been generated with that water. A low zone C scenario would see Niagara River water flows dropping below 3820 m3/s which would reduce the energy generation by half reducing revenue. Zone Lake Erie Outflow m 3 /s Lake Erie Level, m Niagara River Flow, m 3 /s NYPA Allocation capacity 2832 OPG Allocation capacity 1840/2300 (1) Comments Note that water allocation amount depends on time and day of the year in accordance with Niagara Treaty provisions. A 5930~ ~ ~ ~2832 NYPA: Satisfies all energy contracts, energy at or above average without large amounts of spills or for long duration. B 3970~ ~ ~ ~2200 NYPA: Generation as low as ½ of average, not all contracts met. High B Low C Above 7170 Below 3970 Above Below Above 7020 Below NYPA: Significant spill and duration 3~5 yrs. Structural measures to increase conduit capacity may be feasible. Below 510 NYPA: During 3-5 years. Generation 1/2 of normal, revenue greatly reduced, unit moth-balled, staff reduction. A Forebay Not considered to be problematic by 37

38 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Zone A Lake Erie Outflow m 3 /s Lake Erie Level, m Niagara River Flow, m 3 /s NYPA Allocation capacity 2832 and Tailrace Structural integrity OPG Allocation capacity 1840/2300 (1) Comments Note that water allocation amount depends on time and day of the year in accordance with Niagara Treaty provisions. both NYPA and OPG. No serious risk expected under high or low river flow conditions. Table 7: Hydropower coping zones table for the Moses plant in the Niagara River. Levels in metres, IGLD 1985 flows in m3/s. Lake Erie outflow is the sum of Niagara River flow and Welland Canal diversion (Hydropower Technical Working Group, 2011) The three examples above are unique for their respective hydropower plants and structure it represents, however, the scenarios that impact hydropower generation can generally apply to other structures and plants. High water levels can cause permanent structural damage beyond its ability to recover. For example high water levels on the St. Marys can cause major structural damage to the hydropower plants and/or compensating works and the repair or rebuilding process may inhibit the ability to regulate the outflows of Lake Superior for prolonged periods (E.g. six months). During high levels, storm surges can flood the turbine bearings as surge water is forced up into the shaft and the turbine pit (Rose & Yee, 2011). High water levels and flows may exceed the capacity of the plants forcing the spillage of water foregoing energy production of that excess water. As previously mentioned, low water levels will lower the generating capacity which will cause a loss of revenue and power generation. Low water levels will also make it difficult to maintain the minimum tailrace (tailwater) elevation for plants to avoid cavitation damage on their draft tubes, which would cause units to go offline in order to mitigate. Seasonal issues are a typical problem for hydropower plants especially the ones on the St. Marys River which can experience short-term operational difficulties due to ice jams and other ice-related problems in the winter. Some seasonal problems (mainly at the U.S. Government Plant) include, ice getting lodged in the wicket gates which will cause a unit to lose control, damage equipment and cause powerhouse freezing as units go offline (powerhouses are heated from the heat emitted from the hydro generators), and frazil ice acting as slush will reduce power generation. No specific hot spots were listed by the Hydropower TWG. It might be due to the fact that plants and structures are fixed locations therefore any problems will occur at those locations; however, hydropower plants on the St. Marys River and St. Lawrence River were specifically mentioned to be vulnerable to ice problems. Adaptive actions were also not specifically mentioned. During high water levels, hydropower plants will alter their operations in order to cope with conditions such as allocating water elsewhere or spilling excess water. During low water levels, hydropower plants will also alter their operations in order to cope with low levels such as reducing energy output or changing operations to produce more power during higher periods. 38

39 Identifying Vulnerabilities through the Development of Coping Zones September 23, Ecosystem Technical Working Group (Ecosystem TWG) Coping Zones The Ecosystem TWG have compiled estimates on the potential ecological impacts from various lake level regulation alternatives and basin water supply scenarios (Mackey, 2011). The TWG looked at various species and wetlands on the upper Great Lakes that will be impacted by fluctuating water levels and under potential climate change regimes. The ecosystem TWG developed their coping zones based on the environmental coping zone definitions described earlier in section 2.0 of this report. The coping zones were defined from a continuum of biological conditions based on a series of impact scores ranging from 1 to 6 (Mackey, 2011) displayed in figure 22. Coping zone A was derived from ecological impact scores 1 and 2; zone B was based on ecological impact scores 3 and 4; and zone C was based from ecological impact scores 5 and 6. Figure 22: Coping Zone and Threshold Approach for Ecological Performance Indicators (adapted from ETWG 2009) Figure 22 shows the critical threshold between the impact scores 4 and 5 which marks the transition from a zone B to C. This is the point where water conditions begin to cause major changes (impacts) on the biologic community and thus moderate to major changes in the ecosystem function. If a biologic 39

40 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 community experiences a zone C according to the definition above it would have endured major degradation or changes. Should water conditions return to a zone A or zone B after a zone C, the biologic community may not return to its original state, instead it will remain as its altered form (Mackey, 2011). These irreversible impacts are consistent with the original definitions of zone C. Historical water levels ( ) were used as a guide when developing the zone C thresholds because historically there have been very few to no years in a zone C (Mackey, 2011). For many of the zone C scenarios to occur it would require an extended duration at an unfavourable water level (E.g. 5 consecutive years). In many cases zone B conditions are the same as a zone C, however, the zone B requires less time to occur than a zone C. Coping zones were not created on a lake wide scale as most of the other interests; instead they were created on specific ecological performance indicators (PIs). In total, 33 PIs were created to represent biologic communities throughout the upper Great Lakes; however, there are only six performance indicators where zone C conditions could be addressed by a different regulation plan (Ecosystem TWG, 2011). The six PI criterion identifiers are SUP-01, SUP-02, SMG-01, SMQ-01, LMH-07 & LMH-08 and the details of the coping zones for these PIs are listed in table 8 below. Figures 23 to 26 are a graphical representation of the coping zones for SMQ-01, LMH-07 and LMH-08 (graphs do not account for duration) plotted with historical water levels and flows from 1900 to A table with a complete list of the 33 PIs evaluated is available in Appendix B. Specific details about the developments of the coping zones are available in the Ecological Evaluation of Lake Superior Regulation Plans for the International Upper Great Lakes Levels Study report prepared by Mackey and the Ecosystem TWG (2011). The coping zones for each of the PIs generally reflect the following circumstances. 1) Prolonged high water level or flow conditions; 2) Prolonged low water level or flow conditions; 3) Too much or too little water availability in the St. Marys rapids; 4) Alteration of typical seasonal patterns in water level or flow; 5) Reduction in the inter-annual variability of the summertime peak water level; and 6) Compression of long-term range/variability in water levels (i.e., difference between periodic peak levels and water levels during low supply periods). (Mackey, 2011) 40

41 Historic Water Level (m) Historic Water Flows (m 3 /s) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone A Zone B (3 years within 5 years) Zone C (5 consecutive years) Historic Flows (m3/s) 0 Year Figure 23: Ecosystem coping zones for Lake Sturgeon on the St. Marys River (SMQ-01) plotted on historic water flows for the month of June ( ). Same water flow for zone B and C but zone B is 3 out of 5 years and zone C for 5 consecutive years Zone A Zone B Zone C Historic Water Level (m) Year Figure 24: Ecosystem coping zones for eastern Georgian Bay wetlands (LMH-07) plotted on historic water levels (Lake Michigan-Huron) for the months April to October ( ). Coping zone represents present conditions. 41

42 Historic Water Level (m) Identifying Vulnerabilities through the Development of Coping Zones September 23, Zone A Zone B Zone C Historic Water Level (m) Year Figure 25: Ecosystem coping zones for eastern Georgian Bay wetlands (LMH-08) plotted on historic water levels (Lake Michigan-Huron) for the months April to October ( ). Coping zone accounts for GIA 50 years into the future. Criterion Identifier SUP-01 SUP-02 Lake Region Lake Superior Lake Superior Zone B Condition (not applicable) (not applicable) Zone C Condition or Range Compression Metric Range Compression Metric #1: plan-to- Pre-Project ratio for the maximum peak summertime water level when the Pre- Project peak is greater than 0.37 meter above the 109-year mean water level. Range Compression Metric #2: plan-to- Pre-Project ratio of the maximum PI Fact Sheet IDs 3 Proposed by General Objective n/a 1 Wilcox Minimize range compression for Lake Superior. (Goal: plan-to-preproject rations should be as close to 1.0 as possible) n/a 1 Wilcox Minimize range compression for Lake Superior (Goal: plan-to-preproject 42

43 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Criterion Identifier SMG-01 SMQ-01 (figure 23) LMH-07 (figure 24) LMH-08 (figure 25) Lake Region St. Marys River (gates) St. Marys River (flow) Lake Michigan- Huron Lake Michigan- Huron Zone B Condition Compensating Works operated with 4 or more gates open for May-July for any given year. Mean flow rate during June maintained below 1,700 m3/s for any 3 years in a 5- year window. Mean growing season (Apr-Oct) water level is less than meters for any 3 years within a 5-year window. Mean growing season (Apr-Oct) water level is less than meters for any 3 years within a 5 year window. Zone C Condition or Range Compression Metric drawdown of summertime high water levels occurring within 5 years of a peak water level (when the maximum drawdown for Pre Project is at least 0.45 meter). 2 PI Fact Sheet IDs 3 Proposed by General Objective ratios should be as close to 1.0 as possible) (not applicable) 21 Bain et al. Prevent ideal conditions for sea lamprey reproduction Mean flow rate during June maintained below 1,700 m3/s for 5 or more consecutive years. Mean growing season (Apr-Oct) water level is less than meters for a period of 4 or more consecutive years. Mean growing season (Apr-Oct) water level is less than meters for a period of 4 or more consecutive years. Table 8: Ecosystem coping zones for 6 priority performance indicators only. 24 Bain et al. Provide suitable spawning area for lake sturgeon 08, 09 Chow- Fraser et al. 08, 09 Chow- Fraser et al. Maintain fish habitat/access in eastern Georgian Bay wetlands (current conditions) Maintain fish habitat/access in eastern Georgian Bay wetlands (50-year forecast condition) 1 The SUP-01 and SUP-02 range compression criteria for Lake Superior are not linked to specific performance indicators; rather, these criteria are based on expert judgment regarding the water level range requirements for long-term maintenance of healthy and diverse wetland vegetation. 2 These conditions are only evaluated when Pre-Project water levels indicate that supplies are sufficiently low following a peak water level event. 3 PI Fact sheets can be found in The Ecological Evaluation of Lake Superior Regulation Plans for the International Upper Great Lakes Levels Study. Integrated Ecological Response Model Contextual Overview by Scudder D. Mackey, Ph.D. 43

44 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Lake range compression (SUP-01 & SUP-02 in table 8) is a ratio between a proposed regulation plan and pre-project conditions. The closer the ratio is to 1 signifies that the regulation plan is close to preproject conditions and if the ratio is closer to 0 it signifies that water levels for the regulation plan considered are extremely different than the pre-project water levels. This ratio is significant to Lake Superior wetlands because wetlands require naturally occurring water level fluctuations including extremes and Lake Superior regulation has a tendency to reduce extreme peak water levels, limit postpeak drawdown events and prevent extreme low water levels (Mackey, 2011). A regulation plan that keeps water levels closer to pre-project (ratio close to 1) is more beneficial to Lake Superior wetlands. Water availability on the St. Marys River is the driving force for the performance indicator SMG-01. Table 8 below states that if four or more gates from the compensating works are opened between May to July it may raise levels enough to provide satisfactory conditions for sea lamprey (an invasive species) reproduction and give the lamprey mobility to move upstream into Lake Superior. These conditions have been classified as a zone B. Lake sturgeon is already a species at risk and there is a population of them in the St. Marys River. Water flows should remain above 1700 m 3 /s to provide suitable spawning conditions for the sturgeon, however, should these flows drop for an extended period it could lead to a zone B or C for the sturgeon. Figure 23 displays that if flows on the St. Marys River for the month of June are below 1700 m 3 /s for 3 years within a 5 year period the lake sturgeon will be in a zone C, however, should these flows persist for 5 or more consecutive years it would put the lake sturgeon in a zone C. As stated above fluctuating water levels are beneficial to wetlands but extend low water levels are detrimental as it can disconnect wetlands from its adjacent body of water depending on the wetland sill depth. Performance indicators LMH-07 & LMH-08 are displayed in figures 24 & 25 and table 8 and these figures demonstrate problematic water levels (both zone B & C) for the eastern Georgian Bay wetlands. LMH-07 provides the unfavourable water levels under current conditions and LMH-08 provide the same adverse scenarios however accounting for GIA which is discussed later. The table and figures show that an extended period of low water levels will have serious implications on fish habitats as the water regresses away from the wetlands reducing submerged aquatic habitat. If water levels drop below m ( m accounting for GIA 50 years into the future) for any 3 years within a 5 year period this would put the wetland into a zone B. If the water levels further drop to 176 m ( m accounting for GIA 50 years into the future) for 4 consecutive years it is anticipated that there would be irreversible damage to the fish and wildlife community in these wetlands thus putting this wetland in a zone C. Observing figure 24 it is apparent that there has been challenging water levels at the eastern Georgian Bay wetlands since the early 2000s (see photo 4). During this extended period of low water levels there has already been a considerable loss in fish habitat (Mackey, 2011). Based on the wetland sill depth, it is anticipated that there would be a 15% loss of fish habitat for every metre below the 176 m level (Mackey, 2011). 44

45 Identifying Vulnerabilities through the Development of Coping Zones September 23, 2011 Photo 4: Dry dock located on an eastern Georgian Bay wetland in June 2007 The ecosystem has adapted to historical (including extremes) and seasonal water level fluctuations and this natural variability is essential for plant and animal diversity in coastal wetland systems of the Great Lakes (Mackey, 2011). In general the ecosystem is resilient to extreme water level conditions; however, some aquatic habitats are vulnerable to enter a zone B or C scenario when there is long-term degradation due to prolonged high or low water levels or changes in seasonal variability caused by anthropogenic alterations. If the pro-longed high or low water levels happen naturally (without anthropogenic influences), it is recommended by the ETWG to not manipulate or moderate natural high or low water levels to eliminate Zone C occurrences in order to protect the environment (Mackey, 2011). Similar to other interests, the rising and sinking of shorelines caused by GIA will have consequences on wetlands hydrology. As previously mentioned table 8 and figures 24 & 25 above provide examples of how GIA will have an impact on the future of the eastern Georgian Bay wetlands (LMH-07 and LMH-08). In figure 24 under present elevations if water levels drop below 176 m for a period of 4 consecutive years those wetlands will be a zone C (LMH-07). In this region, however, according to figure 2 the earth s crust is raising 24 cm/century in this region, therefore in 50 years (into the future) the shore would have risen 12 cm increasing the elevation of the wetlands by that amount. As a result, in figure 25 the wetlands will be in a zone C if water levels drop below m for a period of 4 consecutive years 50 years into the future (LMH-08). The main adaptive action recommendation is to simply maintain water levels, flows and compression ratios to avoid going into the zone B and C scenarios listed above. Some of the conditions include: avoiding range compression in Lake Superior as a manner to maintain wetland habitat and diversity as its relationship is uncertain, sufficiently maintain St. Marys River flows and levels to provide favourable conditions for fish spawning and maintain water levels to keep wetlands connected to main water 45