Urfe Creek Geomorphic Assessment William Jackson Drive and Earl Grey Avenue City of Pickering Regional Municipality of Durham

Transcription

1 GUIDING SOLUTIONS IN THE NATURAL ENVIRONMENT Urfe Creek Geomorphic Assessment William Jackson Drive and Earl Grey Avenue City of Pickering Regional Municipality of Durham Prepared For: Trillium Housing Oak Non-Profit Corporation Prepared By: Beacon Environmental Limited Date: Project: June MARKHAM 80 Main Street North Markham, ON L3P 1X5 T) F) BRACEBRIDGE 126 Kimberley Avenue Bracebridge, ON P1L 1Z9 T) F) GUELPH 373 Woolwich Street Guelph, ON N1H 3W4 T) F) PETERBOROUGH 305 Reid Street Peterborough, ON K9J 3R2 T)

2 T a b l e o f C o n t e n t s p a g e 1. Introduction Policy Context Endangered Species Act (2007) Provincial Policy Statement (2014) Toronto and Region Conservation Authority Regulations and Guidelines Conservation Authorities Act (Ontario Regulation 166/06) The Living City Policies (2014) Regional Municipality of Durham Official Plan (Office Consolidation, 2015) City of Pickering Official Plan (2010) Duffin Heights Environmental Servicing Plan (2008) Duffin Heights Neighbourhood Development Guidelines (2009) Desktop Assessment Background Review Geomorphology Aquatic Habitat Historic Assessment Existing Conditions Reach Delineation Rapid Assessments Methods Results Reach UC Reach UC Analysis Meander Belt Width Policy Conformance Conclusions References F i g u r e s Figure 1. Site Location... after page 2 Figure 2. Meander Belt and Photo Locations... after page 6

3 T a b l e s Table 1. Summary of Key Historic Observations... 6 Table 2. General Reach Characteristics Urfe Creek... 9 Table 3. Rapid Assessment Results Urfe Creek... 9 A p p e n d i c e s A. Historic Aerial Imagery B. Photographic Record

4 1. Introduction Beacon Environmental Limited (Beacon) has been retained by Trillium Housing Oak Non-Profit Corporation to undertake a geomorphic assessment for the proposed development located at William Jackson Drive and Earl Grey Avenue in the City of Pickering, Regional Municipality of Durham (hereto referred as the subject property, refer to Figure 1). It is our understanding that the portion of Urfe Creek located adjacent to the subject property has been classified as recovery habitat for Redside Dace (Clinostomus elongates) by the Ministry of Natural Resources and Forestry (MNRF). This minnow species receives protection under the Endangered Species Act (ESA, 2007). Ontario Regulation 242/08 of the ESA (2007) defines recovery regulated habitat as the meander belt width, plus vegetated areas or agricultural lands within 30 metres of the meander. The purpose of this report is to identify the extent of recovery regulated habitat in relation to the subject property. As the relevant reaches of Urfe Creek are situated within a confined valley system, this assessment will reference the meander belt width, but will also consider valley floor dimensions. Specifically, the following tasks were undertaken in support of the study: Background review of available materials (topographic mapping, aerial photography, watershed reports); Desktop assessment to delineate reaches based on underlying geomorphic controls; A scoped field assessment to characterize existing geomorphic conditions, confirm valley floor dimensions, and document evidence of active channel processes; Following applicable policies and guidelines, delineate the meander belt width on a reach basis, referencing recent aerial imagery, historic trends in channel planform (where feasible), and valley floor dimensions; and In accordance with Ontario Regulation 242/08, delineate the limit of regulated Redside Dace recovery habitat, referencing 30 m from the meander belt. 2. Policy Context 2.1 Endangered Species Act (2007) As previously noted, the relevant reaches of Urfe Creek located adjacent to the subject property have been identified by MNRF as a watercourse that is being used or was used at any time during the previous 20 years, by a Redside Dace, and that provides suitable conditions for a Redside Dace to carry out its life processes. This minnow species and its habitat receive protection under ESA (2007). Redside Dace recovery habitat is defined under Ontario Regulation 242/08 as a watercourse that was used by Redside Dace at any time in the past or that is located in the same or adjacent sub-watershed as an area that provides suitable conditions for successful stream corridor rehabilitation and for natural recolonization of the species, in addition to the area encompassing the meander belt width of said watercourse, and the vegetated area or agricultural lands that are within 30 metres of the meander belt width. Page 1

5 2.2 Provincial Policy Statement (2014) The Provincial Policy Statement (MNRF 2014) issued under the Planning Act (1990) outlines areas of provincial interest with respect to natural hazards. In support of the Policy Statement, a Technical Guide - Rivers and Streams: Erosion Hazard Limit document was prepared (MNR 2002) to outline standardized procedures for the delineation and management of riverine erosion hazards in the Province of Ontario. The guide presents erosion hazard protocols based on two generalized landform systems through which watercourses flow: confined and unconfined valley systems. Through this approach, the meander belt width plus an erosion access allowance is defined to determine the erosion hazard limit of an unconfined valley system. For confined valley systems, the erosion hazard limit is governed by geotechnical considerations, including the stable slope allowance and an applicable toe erosion allowance (i.e., channel migration component). 2.3 Toronto and Region Conservation Authority Regulations and Guidelines Conservation Authorities Act (Ontario Regulation 166/06) The Toronto and Region Conservation Authority (TRCA) regulates land use activities in and adjacent to wetlands, watercourses and valleylands under Ontario Regulation 166/06 (Regulation for Development, Interference with Wetlands and Alterations to Shorelines and Watercourses) made under the Conservation Authorities Act. Subject to conformity with the municipality s Official Plan, the completion of appropriate studies and application for Conservation Authority permits, The Authority may grant permission for development within these areas if it can be proven that control of flooding, erosion, pollution or the conservation of land will not be affected by the development The Living City Policies (2014) The TRCA s Living City Policy was approved in November 2014 and replaces the Valley and Stream Corridor Management Program (1994). The Living City Policy document, among other matters, implements current federal, provincial and municipal legislation, policies and agreements affecting conservation authorities; and implements the policies for TRCA s updated section 28 of Ontario Regulation 166/06. For purposes of implementing TRCA s Environmental Management Policies: Confined River or Stream Valleys are considered Valley Corridors; and Unconfined River or Stream Valleys are considered Stream Corridors. According to the Living City Policy, the boundaries of a valley or stream corridor generally require a minimum 10 m setback from the greater of: Physical top of the valley feature; Long term stable top of slope, where geotechnical concerns exist (which must be confirmed through an appropriate geotechnical analysis); Regulatory floodplain; Meander belt; and Page 2

6 Earl Grey Avenue Urfe Creek William Jackson Drive C:\Dropbox\Dropbox (Beacon)\All GIS Projects\2018\218020\MXD\218020_1_Figure01_SiteLocation_ mxd Site Location Brock Road Rossland Road Taunton Road Church Street North Ajax Liatris Drive Site Location Figure 1 South of Earl Grey Drive, Geomorphic Assessment UTM Zone 17 N, NAD 83 First Base Solutions Web Mapping Service Metres - 1:2,000 Project June, 2018 D

7 Limits of significant vegetation which is contiguous with the valley corridor. It is the policy of TRCA: That erosion hazard limits will be determined through site specific field investigations and technical reports where required, in accordance with the text of TRCA s Regulation and Provincial and TRCA standards. Where erosion hazard limits are required and not available, or where existing erosion hazard information does not meet current Provincial or TRCA standards, TRCA may require the erosion hazard to be determined by a qualified professional, at the expense of the proponent, to the satisfaction of TRCA. The Belt Width Delineation Procedures (TRCA 2004) document outlines standards for delineating the meander belt width in TRCA jurisdiction. 2.4 Regional Municipality of Durham Official Plan (Office Consolidation, 2015) The Regional Municipality of Durham published its latest Official Consolidated Plan on June 26, It protects natural heritage features through a Greenlands system. According to the Official Plan: The Greenlands System includes areas with the highest concentration of sensitive and/or significant natural features and functions. These areas are to be managed as a connected and integrated natural heritage system recognizing the functional inter-relationships between them. The main features of the Greenlands System, particularly the Oak Ridges Moraine, valley systems and the Waterfronts, shall be protected for their special natural and scenic features, their roles as predominant landscape elements in the Region and the recreational opportunities that they facilitate. Further, linking the waterfronts with the Oak Ridges Moraine through the connecting valley shall be a primary objective of the continuous Greenlands System, as is linking of the valley systems themselves. Greenlands include the following Key Natural Heritage Features (KNHF). The list of KNHFs is similar, but not identical, to the PPS list: significant habitat of endangered and threatened, special concern and rare species; fish habitat; wetlands; Life Science Areas of Natural and Scientific Interest (ANSIs); significant valleylands; significant woodlands; significant wildlife habitat; sand barrens, savannahs and tallgrass prairies; and alvars. The Region of Durham Official Plan also recognizes the following Key Hydrologic Features (KHFs): permanent and intermittent streams; Page 3

8 wetlands; lakes and their littoral zones; kettle lakes and their surface catchment areas; seepage areas and springs; and aquifers and recharge areas. The subject property falls within an Urban Area and is designated on Schedule A, Map A-4 Regional Structure of the Durham Region Official Plan as Living Areas and Schedule B, Map B-1d Natural Heritage System & Key Natural Heritage and Hydrologic Features indicates Key Natural Heritage and Hydrologic Features adjacent to the subject property. Section states that development or site alteration is not permitted within a key natural heritage and/or hydrologic feature and associated vegetation protection zone. 2.5 City of Pickering Official Plan (2010) The current Official Plan for the City of Pickering (Edition 6) is dated February The Official Plan protects natural heritage features through the Open Space System, which incorporates three types of natural areas: core areas, corridors and linkages. The subject property is located within the northern limits of the South Pickering Urban Area, within the Duffin Heights Neighbourhood and is therefore subject to the corresponding policies that were adopted as part of the Duffin Heights Environmental Servicing Plan (2008) Duffin Heights Environmental Servicing Plan (2008) The Duffin Heights Environmental Servicing Plan (ESP) was prepared in order to determine the environmental limits and servicing requirements for lands within the planning area. Specifically, the ESP confirmed the limits of the Natural Heritage System (NHS) west and east of Brock Road, addressing the requirements of the Duffin Heights Neighbourhood policies of the Pickering Official Plan Duffin Heights Neighbourhood Development Guidelines (2009) These guidelines are a component of the Compendium Document to the City s Official Plan. This document is applicable to lands on both sides of Brock Road and outlines specific development guidelines for the Duffin Heights Neighbourhood. Figure A of this guideline shows the subject property as having a designation of Brock Road Streetscape the Urfe Creek Valley system is designated as Open Space. Section 1.4 outlines the development objectives for the neighbourhood and states that it is the intent of the City to preserve and maintain the ecological function of the tableland forest and valleylands while promoting the development of Brock Road. Page 4

9 3. Desktop Assessment 3.1 Background Review Geomorphology The subject property is situated within Urfe Creek subwatershed of Duffins Creek. The headwaters of Urfe Creek originate on the glacial till plain that extends throughout the majority of the subwatershed, and transitions to glacial lake beach deposits towards the downstream portion of the watershed and confluence with East Duffins Creek. The Fisheries Management Plan for Duffins Creek and Carruthers Creek identified the portion of Urfe Creek adjacent to the subject property as a third order stream (TRCA 2004) Aquatic Habitat The State of the Seaton Lands report (TRCA 2007) summarizes aquatic habitat conditions within the large development area immediately upstream of the subject property. The State of the Seaton Lands report (TRCA 2007) characterizes Urfe Creek as a largely cold-coolwater system. Evidence of sediment loading and nutrient enrichment have been identified as stressors to the aquatic community and aquatic habitat health within the subwatershed. The Watershed Plan for Duffins Creek and Carruthers Creek noted the weir control structure and online pond within Urfe Creek adjacent to the subject property as an instream barrier to fish passage (TRCA 2003). This, along with several other structures, have been identified by TRCA as restoration opportunities within the Urfe Creek subwatershed. TRCA has initiated a project to remove the weir structure. 3.2 Historic Assessment The following section presents an overview of historic conditions in the vicinity of the subject property with respect to land use, land cover and channel conditions. Historic analyses provide insight into the scale of natural and human-induced changes within a watershed, particularly the degree to which channel planform adjustment and land use has changed over time. In support of the historic assessment, black and white aerial coverage from 1974 and recent digital colour imagery were analysed and compared to obtain a simple, qualitative assessment of the degree of land use and channel planform change over time (Appendix A and Table 1). Table 1 provides a summary of specific observations regarding change in land use based on available historical aerial imagery. Page 5

10 Table 1. Summary of Key Historic Observations Time Period 1974 Scale, Source 1:12,000 Northway Photomap/Remote Sensing Ltd Google Earth Description of Change The east-west rail line and a hydro corridor have been constructed as well as most of the major roads in the area. Land use is generally dominated by agriculture, with tree cover limited to the Urfe Creek valley system. Individual residential homes and farms can be observed along Brock Road. Due to dense tree cover within the valley, channel planform could not be discerned. The Urfe Creek weir structure and upstream backwater area can be observed adjacent to the subject property. The intersection of Brock Road and Taunton Road has been realigned. Immediately north and south of the subject property, residential subdivisions have been constructed. Pickering Golf Club can be observed south and east of the subject property. A cart path crossing of Urfe Creek has been constructed upstream of the weir structure. The Urfe Creek weir structure and upstream backwater area can be observed adjacent to the subject property. Due to dense tree cover within the valley, channel planform could not be discerned. 4. Existing Conditions 4.1 Reach Delineation To facilitate a systematic evaluation of the relevant portion of Urfe Creek within the study area, the watercourse was delineated into reaches. Reaches are homogenous sections of channel with regard to form and function and can, therefore, be expected to behave consistently along their length to changes in hydrology and sediment inputs, as well as to other modifying factors (Montgomery and Buffington, 1997; Richards et al., 1997). Based on factors including sinuosity, degree of historic alteration and riparian vegetation, the portion of Urfe Creek adjacent to the subject property was delineated into two (2) reaches: Reaches UC1 and UC2 (Figure 2). 4.2 Rapid Assessments Methods In support of a previous study, existing geomorphic conditions along the relevant portion of the Urfe Creek were characterized on September 29, The following standardized rapid visual assessment methods were applied on a reach basis: Page 6

11 UC2!(!(!(!( U r fe Creek!( 7!( 6!( 5!( 4!( 3!( 2!( 1 UC1 C:\Dropbox\Dropbox (Beacon)\All GIS Projects\2018\218020\MXD\218020_Figure2_MeanderBelt_ mxd Legend Subject Property Proposed Development!( Photo Location Reach Breaks Extent Assessed Meander Belt Width (57 m) Meander Belt + 30m Buffer Watercourse Stormwater Outfall Channel Meander Belt and Photo Locations South of Earl Grey Drive, Geomorphic Assessment UTM Zone 17 N, NAD 83 First Base Solutions Web Mapping Service Metres Figure 2-1:2,500 Project June 2018

12 1. Rapid Geomorphic Assessment (RGA MOE 2003) The RGA documents observed indicators of channel instability by quantifying observations using an index that identifies channel sensitivity. Sensitivity is based on evidence of aggradation, degradation, channel widening and planimetric form adjustment. The index produces values that indicate whether the channel is stable/in regime (score <0.20), stressed/transitional (score ) or in adjustment (score >0.41). 2. Rapid Stream Assessment Technique (RSAT Galli 1996) The RSAT uses an index to quantify overall stream health and includes the consideration of biological indicators (Galli 1996). Observations concerning channel stability, channel scouring/sediment deposition, physical in-stream habitat, water quality, and riparian habitat conditions are used to calculate a rating that indicates whether the channel is in poor (<13), fair (13-24), good (25-34), or excellent (35-42) condition. 3. Downs Classification Method (Downs 1995) The Downs (1995; outlined in Thorne et al. 1997) classification method infers present and future potential adjustments based on physical observations, which indicate the stage of evolution, and type of adjustments that can be anticipated based on the channel evolution model. The resultant index classifies streams as stable, laterally migrating, enlarging, undercutting, aggrading, or recovering Results Results of the rapid assessments are summarized in Table 2 and Table 3 below. A photographic record of site conditions at the time of the assessment is provided in Appendix B Reach UC1 Based on the extent assessed, Reach UC1 was characterized as a heavily modified, moderately sinuous channel situated within a confined valley system. Moderate gradient and low degree of entrenchment were observed. Riparian vegetation was characterized as continuous, extending greater than 5 channel widths laterally. Vegetation consisted of trees with shrubs. Bank angles ranged between degrees with 30-60% of banks identified as exhibiting indicators of active erosion, such as scour and undercutting. On a localized scale, the morphology of the channel was influenced by the presence of a large concrete weir structure. Bank materials were dominated by sand and silt with some clay and gravel. Bankfull widths and depths ranged from m and m, respectively. Riffle substrate consisted of sand, gravel, scattered cobble, and erratic boulders. Pool substrate consisted of silt, sand, gravel, fine cobble, and erratic boulders. Another channel disturbance includes a narrow wooden pedestrian crossing of the valley. RGA results indicated that Reach UC1 was in transition, with a score of Widening was identified as the dominant mode of adjustment with degradational processes noted as secondary. Evidence of widening included fallen/leaning trees, exposed tree roots, basal scour on both sides of the channel Page 7

13 through riffles, slumping banks and outflanked concrete weir structure. Undermined concrete aprons and scour pool formation downstream of the weir were noted as evidence of degradation. Minor aggradation was noted in the form of deposition in the overbank zone. Evidence of planform adjustment was observed through chute formation. An RSAT score of 25 indicated a good degree of overall ecological health, with narrow riparian habitat conditions identified as the primary limiting factor. The Downs model reflected the RGA evaluation of this reach through a classification of E enlarging based on observed erosion on both banks and a scoured bed Reach UC2 Reach UC2 was characterized as a heavily modified, moderately sinuous channel situated within a confined valley system. Moderate gradient and low degree of entrenchment were observed. Riparian vegetation was characterized as fragmented, extending 1 to greater than 5 channel widths and consisted of trees with shrubs and manicure lawn in the golf course. Bank angles ranged between degrees with 30-60% of banks identified as exhibiting indicators of active erosion, such as scour and undercutting. On a localized scale, the morphology of the channel was influenced by the presence of 2 concrete weir structures. The downstream weir structure (identified as the reach break, refer to Figure 2) has resulted in the formation of backwater zone with sediment deposition and island formation. Extensive erosion was observed in the vicinity of the upstream weir structure and observed evidence of multiple flow paths indicated that, at higher flow conditions, the weir structure would be by-passed. There was also evidence of flow piping through portions of the berm adjacent to the structure. Bank materials were dominated by sand and silt with some clay and gravel. Riffle substrate consisted of sand, gravel, scattered cobble, and erratic boulders. Pool substrate consisted of silt, sand, gravel, fine cobble, and erratic boulders. Other channel disturbances included a stormwater outfall channel and a golf cart path crossing. The upstream portion of the stormwater outfall channel feature is a constructed bioswale feature which transitions to an outlet pool and steep gulley feature along the valley slope. RGA results indicated that Reach UC2 was in transition, with a score of Widening was identified as the dominant mode of adjustment with degradational processes noted as secondary. Evidence of widening included fallen/leaning trees, exposed tree roots, basal scour on both sides of the channel through riffles, slumping banks and outflanked weir wing walls. Undermined concrete aprons, elevated storm outfalls and scour pool formation downstream of storm outfalls were noted as evidence of degradation. Deposition in the overbank zone was observed an indicator of aggradation. An RSAT score of 25 indicated a good degree of overall ecological health, with narrow riparian habitat conditions identified as the primary limiting factors. The Downs model reflected the RGA evaluation of this reach through a classification of E enlarging based on observed erosion on both banks and a scoured bed. Page 8

14 Table 2. General Reach Characteristics Urfe Creek Reach Bankfull Width (m) Bankfull Depth (m) UC UC2 - - Riffle Substrate Sand, gravel, cobble and erratic boulders Sand, gravel, cobble and erratic boulders Riparian Vegetation Trees, shrubs Trees, shrubs, manicured golf lawn Notes Channel morphology influenced by concrete weir structure at upstream extent Significant erosion was observed in the vicinity of the weir. Existing pedestrian crossing Channel morphology influenced by concrete weir structure Ponding with island formation observed upstream of weir Golf cart path crossing Stormwater outfall channel Table 3. Rapid Assessment Results Urfe Creek Reach UC UC Rapid Geomorphic Assessment (RGA) Dominant Score Condition Mode of Adjustment In Transition In Transition Score Rapid Stream Assessment Technique (RSAT) Condition Widening 25 Good Widening 25 Good Limiting Feature Riparian Habitat Conditions Riparian Habitat Conditions Downs Classification Method E enlarging E enlarging 5. Analysis 5.1 Meander Belt Width The meander belt width is generally defined as the lateral extent that a meandering channel has historically occupied and will likely occupy in the future. In situations where a watercourse is confined, such as Reaches UC1 and UC2 of Urfe Creek, the valley wall acts a constraint to channel migration. Following the TRCA (2004) Chapter 5 procedures, the meander belt width was delineated based on the lateral extent of the outermost meander bends within each reach, and valley floor dimensions, a meander belt width of 57 m is recommended for Reaches UC1 and UC2 (Figure 2). Page 9

15 While historic aerial imagery was considered as part of this assessment, it was not directly referenced for the meander belt as vegetative cover made it difficult to accurately determine the channel planform. That stated, topographic mapping was reviewed to ensure that the meander belt dimension reflected the lateral extent of the floodplain. As previously noted, the meander belt dimension does not relate to erosion hazard limits associated with the watercourse and valley lands. Lands that are within 30 m of the meander belt are also identified on Figure 2 as they pertain to the subject property. 5.2 Policy Conformance As the procedures used to delineate the meander belt are in accordance with applicable guidelines (TRCA 2004), and it is our understanding that MNRF considers these procedures as the standard practice for the determination of recovery Redside Dace regulated habitat limits, it is our opinion that the findings of this report are in conformance with the TRCA LCP (2014) and Ontario Regulation 242/ Conclusions Beacon Environmental Limited (Beacon) was retained by Trillium Housing Oak Non-Profit Corporation to undertake a geomorphic assessment for the lands located at William Jackson Drive and Earl Grey Avenue in the City of Pickering, Regional Municipality of Durham. In order to identify the extent of recovery regulated habitat in relation to the subject property, the meander belt was delineated for the relevant reaches of the Urfe Creek (Reaches UC1 and UC2) located adjacent to the subject property. The following points summarize the findings of this study: A review of historic aerial photographs and topographic mapping indicated that Urfe Creek adjacent the subject property is within a confined valley system with mature riparian vegetation. Rapid geomorphic assessment results for Reaches UC1 and UC2 identified the reaches as being in a transitional state (scores of 0.29 and 0.30, respectively) with evidence of widening as the dominant mode of adjustment. The RSAT assessment indicated Reaches UC1 and UC2 displayed a good degree of overall ecological health, with riparian habitat conditions flagged as the limiting factor to overall stream health. To determine the extent of Redside Dace recovery habitat, a meander belt width of 57 m was recommended for Reaches UC1 and UC2 following the TRCA (2004) guidelines and referencing the available historic record, existing channel planform and valley floor dimensions. In conformance with Ontario Regulation 242/08, lands within 30 m of the meander belt have been identified. Page 10

16 Should you have any questions or require any additional information please contact the undersigned. Report prepared by: Beacon Environmental Report reviewed by: Beacon Environmental Alex Gitto, M.Sc. Geomorphic Systems Analyst Shelley Gorenc, M.Sc., P.Geo. Senior Geomorphologist Page 11

17 7. References City of Pickering Duffin Heights Environmental Servicing Plan. City of Pickering Duffin Heights Neighbourhood Development Guidelines. City of Pickering Office Consolidation of the Pickering Official Plan, February Edition 6. Chapman and Putnam Physiography of Southern Ontario, 3rd Edition. Ontario Geological Survey, Special Vol. 2. Downs, P.W Estimating the probability of river channel adjustment. Earth Surface Processes and Landforms. 20: Galli, J Rapid stream assessment technique, field methods. Metropolitan Washington Council of Governments. 36pp. Ministry of Environment Revised Stormwater Management Guidelines Draft Report. Ministry of Municipal Affairs and Housing Provincial Policy Statement (Policy 3.1: Natural Hazards). Ministry of Natural Resources Technical Guide: River and Stream Systems: Erosion Hazard Limit. Montgomery, D.R and J.M. Buffington Channel-reach morphology in mountain drainage basins. Geological Society of America Bulletin, 109 (5): Ontario Ministry of Natural Resources Endangered Species Act (S.O. 2007, Chapter 6). Regional Municipality of Durham Office Consolidation Copy of the Official Plan of the Regional Municipality of Durham. June 26, Richards C., Haro R.J., Johnson L.B., Host G.E Catchment- and reach-scale properties as indicators of macroinvertebrate species traits. Freshw. Biol. 37: Page 12

18 Toronto and Region Conservation Authority (TRCA) A Watershed Plan for Duffins Creek and Carruthers Creek. Toronto and Region Conservation Authority (TRCA) Belt Width Delineation Procedures. Prepared by PARISH Geomorphic Ltd. Toronto and Region Conservation Authority (TRCA) Fisheries Management Plan for Duffins Creek and Carruthers Creek. Toronto and Region Conservation Authority Ontario Regulation 166/06 - Regulation for Development, Interference with Wetlands and Alterations to Shorelines and Watercourses. May 4, Toronto and Region Conservation Authority (TRCA) State of the Seaton Lands: A Report on the Enhanced Aquatic Habitat Assessment of Toronto and Region Conservation Authority (TRCA) The Living City Policies. Page 13

19 Appendix A H i s t o r i c A e r i a l I m a g e r y

20 A p p e n d i x A - H i s t o r i c A e r i a l I m a g e r y Coverage: 1974 Scale: 1:12:000 Image ID: N/A Source: Northway Photomap Page A-1

21 A p p e n d i x A - H i s t o r i c A e r i a l I m a g e r y Coverage: 2017 Scale: 1:7:000 Image ID: N/A Source: Map data 2018 Google Page A-2

22 Appendix B P h o t o g r a p h i c R e c o r d

23 A p p e n d i x B A p p e n d i x B Photographic Record Photo 1. (Photo Location 1) Reach UC - Upstream view of riffle and pedestrian bridge. Note leaning/fallen trees and gravel/cobble substrate. Photo 2. (Photo Location 2) Reach UC1 - Downstream view of general channel conditions. Note: instream woody debris and gravel bar formations. Photo 3. (Photo Location 3) Reach UC1 - Downstream view of basal scour and undercutting (exposing tree roots). Photo 4. (Photo Location 4) Reach UC1 - Upstream view of weir structure. Note: formation of scour pool downstream of weir. Page B-1

24 A p p e n d i x B Photo 5. (Photo Location 4) Reach UC2. Erosion observed around concrete weir structure. Photo 6. (Photo Location 5) Reach UC2. Downstream view of backwater zone associated with weir structure. Note: gabion bank protection upstream of the wing wall (arrow). Photo 7. (Photo Location 6) Reach UC2. Upstream view of golf cart path crossing. Photo 8. (Photo Location 7) Reach UC2. Downstream view of large woody debris jam and upstream bar formation (arrow). Page B-2

25 A p p e n d i x B Photo 9. (Photo Location 7) Reach UC2. Upstream view of channel conditions. Note: fallen trees and gravel bar formation (arrow). Photo 10. (Photo Location 8) Reach UC2. Upstream view of outflanked weir structure. Photo 11. (Photo Location 8) Reach UC2. Upstream view of outflanked weir structure. Note: larger storm events bypass the structure (arrow). Photo 12. (Photo Location 8) Reach UC2. Downstream view of stormwater outfall channel confluence with Urfe Creek (arrow) at outflanked weir structure. Page B-3

26 A p p e n d i x B Photo 13. (Photo Location 9) Reach UC2. Downstream view of debris jam upstream of the outflanked weir. Photo 14. (Photo Location 9) Reach UC2. View of Urfe Creek upstream of the weir. Note: backwater effect observed. Photo 15. (Photo Location 10) Upstream view of stormwater outfall channel near confluence with Urfe Creek. Photo 16. (Photo Location 11) Upstream view of stormwater outfall channel. Page B-4