Carruthers Creek Watershed Plan: Hydrogeology
Prepared by: Dr. Richard Gerber and Mike Doughty, Oak Ridges Moraine Groundwater Program for Toronto and Region Conservation Authority ~ conservation and the Region of Durham for The Living City® Final revision: 25 July 2017 This study was funded by the Region of Durham.
Prepared by: Dr. Richard Gerber and Mike Doughty, Oak Ridges Moraine Groundwater Program, for Toronto and Region Conservation Authority, 2017
Reviewed for Toronto and Region Conservation Authority (TRCA) by: Gary Bowen, Watershed Specialist Duffins Carruthers and Great Lakes Advisor, TRCA
For more information: www.trca.ca [email protected] e cons·e;;,atio_n for The Living City Carruthers Creek Watershed Plan
Phase 1 Technical Reports
Foreword
The Region of Durham recognises watershed plans as an effective tool in informing the management of the Durham’s water resources, natural heritage, and natural hazards, such as flooding. In 2015, the Region retained the Toronto and Region Conservation Authority (TRCA) to update the watershed plan for Carruthers Creek.
This four year study will build upon the goals, objectives, and management recommendations established in the 2003 watershed plan for Duffins Creek and Carruthers Creek, thereby ensuring a continuum of management efforts to achieve the desired ecological and sustainability objectives for the watershed.
The following report was prepared by Dr. Richard Gerber and Mike Doughty of the Oak Ridges Moraine Groundwater Program (ORMGP) under the direction of TRCA. Given the specialised expertise and experience of the professional geologists at the ORMGP, and the organisation’s relationship with the Region of Durham, TRCA commissioned the hydrogeology summary as one of the series of technical reports that were prepared at the end of the first phase of the watershed plan development process to characterize the current conditions of the watershed. Information contained in these reports will provide the knowledge base necessary to develop management recommendations during Phase 2. As with the reports written by TRCA staff, this report was subjected to an independent peer review process. The final integrated watershed plan will be completed by the end of Phase 2. Carruthers Creek Watershed Plan
Phase 1 Technical Reports
Introduction: Watershed Plan Study Area
Carruthers Creek is a relatively small watershed with a drainage area of approximately 3,748 hectares (9,261 acres), ranging from two to three kilometres in width, and only 18 kilometres in length (see map below). It is the easternmost watershed in TRCA's jurisdiction and is located entirely in the Region of Durham. At the request of the Region of Durham, a small section of lands in East Duffins Creek subwatershed, which are immediately adjacent to Carruthers Creek watershed and outside of the provincial Greenbelt, were included in the study area.
The watershed occurs within the South Slope and Glacial Lake Iroquois physiographic regions, south of the Oak Ridges Moraine. Topographically, most of Carruthers Creek watershed is flat to slightly rolling. The exceptions are low hills associated with the Lake Iroquois Shoreline, notably the Kinsale Raised Shoreline immediately west of Audley Road and south of Highway 7, and the main valley feature of Carruthers Creek itself, which forms a distinct but shallow ravine from Taunton Road south to Highway 401.
Carruthers Creek’s headwaters form to the south of the Oak Ridges Moraine in the City of Pickering. Both the east and west branches of the creek originate north of Concession 8; their confluence is immediately north of Taunton Road and the creek enters Lake Ontario in the Town of Ajax. Carruthers Creek contains a total of 61 kilometres of stream channels. Historically, portions of the watershed would have supported cold water fish populations including Brook trout, Atlantic salmon, Slimy sculpin, and Mottled sculpin. Instream barriers to fish movement in the watershed adversely impact the aquatic system by limiting access to feeding and spawning areas, increasing water temperature, and affecting sediment transport. In addition, some instream structures increase water velocities to the point where fish passage is prevented. Instream structures that act as barriers to fish passage include dams, weirs, road and rail crossings, and some culverts.
Carruthers Creek watershed lies in the Great Lakes-St. Lawrence floristic region, which is comprised of mixed coniferous-deciduous forest. There are two provincial Areas of Natural and Scientific Interest (ANSl), as designated by the Ontario Ministry of Natural Resources and Forestry, in the watershed: the Kinsale Raised Shoreline Earth Science ANSI, designated for its distinct geological character as a well preserved part of the ancient Lake Iroquois Shoreline; and Shoal Point Marsh Life Science ANSI, which is included in the coastal Carruthers Creek Wetland Complex Provincially Significant Wetland. Two smaller wetlands are evaluated as Locally Significant: the Rossland Road Wetland Complex and the Salem Road Wetland Complex. The Carruthers Creek Wetland Complex is divided into two Environmentally Significant Areas: the coastal Carruthers Marsh and the Carruthers Creek Forest, a few hundred metres inland.
Long-term precipitation and air temperature patterns in the watershed are summarised from data collected by Environment and Climate Change Canada at the nearby Oshawa Water Pollution Control Plant station. In 2015, precipitation volumes of 985 mm exceeded the 30 year (1981-2010) normal of 892 mm, however the 2016 volumes were significantly lower at approximately 614 mm. For three of the last nine years, the total volume of precipitation exceeded the 30 year normal. Lower than normal precipitation volumes were reported in the years 2013, 2015, and 2016.
Stream flow records for the watershed are related to climate patterns. Preliminary water quantity data suggest that 2015 was a wet year in terms of stream flow and 2016 was significantly drier. Although stream flow has only been measured in the watershed for a relatively short period of record, a wide range of climatic conditions has been observed.
Carruthers Creek watershed is mainly rural north of Highway 7. From Highway 7 south to Taunton Road, the majority of lands are in the Protected Countryside of the provincial Greenbelt, however there is a noticeable loss of the integrity of the natural heritage system due to clearing of vegetation and filling. Low to medium density suburban development predominates from Taunton Road south to the lakeshore. Lands currently mapped as rural in the urban areas of Ajax are expected to be developed as employment lands to meet future demands. The older parts of the built urban area have little to no stormwater controls, while the newer parts include standard stormwater quality and quantity ponds accompanied by low impact development (LID) technologies. There is also a flood vulnerable area in the Pickering Beach neighbourhood of Ajax.
As expected, there are differences in agricultural land use in the upper reaches versus mid-reaches of the watershed which may be attributed to land tenure, drainage and soil properties, or a combination of factors. Horticulture dominates the east catchment, whereas the west catchment is predominantly cash crops and at least one livestock operation, although horticulture is also present. In the urban areas of Ajax, some lands slated for development are still cultivated with cash crops as an interim use. Overall, the land use in this small watershed is in transition, therefore the characterization provided by the field work in Phase 1 of the watershed plan is an excellent benchmark for future study and decision- making. Regular monitoring during and following this watershed planning process continuously improves our understanding of the watershed and will help to guide ongoing decision-making to protect, restore, and enhance Carruthers Creek watershed. Carruthers Watershed N D Pla n Study ArH & C Toronto and Reg ion • onservahon A c:J Watershed Boundary for The Living City- Carruthers CreekWatershed Plan [ZJGreenbelt Boundary Natural Areas Date-: July2017 Study Area Land Use 201 S 1111 Created by: T.R.C.A. Information Services/Information Technologie s Oisdaimer: GolfCou rse The Data us ed tocreatethism ap was compiled from a varietysources and dates. TheT.R.C.A. takes noresponsibility for errors or omissions Agricultural/Rural in the data and retains the right tom ake changes and corrections at anytime without notice. For further information aboutthe o.s 4 Rural Estate data on this map, please contact theT.R.C.A. GIS Depart ment. ( 416) 661-6600. -=-=----====----•KM 1111 Urban Carruthers Creek Watershed Plan: Hydrogeology
640000 6SOOOO 660000 670000 630000 Easting (m)
Prepared for The Regional Municipality of Durham by Richard Gerber & Mike Doughty
v02 – July 25, 2017 TRCA Carruthers Creek – Hydrogeology
Table of Contents
1.0 INTRODUCTION...... 4 1.1 Data Sources...... 4 2.0 PHYSICAL SETTING & GEOLOGY ...... 7 2.1 Physiography...... 7 2.2 Climate ...... 7 2.3 Geology ...... 12 2.3.1 Bedrock...... 17 2.3.2 Scarborough Formation...... 21 2.3.3 Sunnybrook Drift...... 21 2.3.4 Thorncliffe Formation...... 22 2.3.5 Newmarket Till...... 22 2.3.6 Oak Ridges Moraine Deposits ...... 23 2.3.7 Halton Till ...... 24 2.3.8 Surficial Glaciolacustrine Deposits...... 24 3.0 HYDROGEOLOGY ...... 25 3.1 Hydrostratigraphy ...... 25 3.1.1 Groundwater Use ...... 26 3.2 Groundwater Recharge...... 29 3.3 Groundwater Flow ...... 33 3.3.1 Hydraulic Properties ...... 46 3.4 Groundwater Discharge ...... 51 3.5 Groundwater Quality...... 58 3.6 Numerical Groundwater Flow Modelling...... 61 4.0 SUMMARY AND CONCLUSIONS...... 64 5.0 REFERENCES...... 66
List of Tables
Table 1: Hydrostratigraphic units within the Carruthers Creek watershed...... 25 Table 2: Summary of estimated recharge rates for different geologic deposits and physiographic regions applicable to the Carruthers Creek watershed...... 30 Table 3: Groundwater level fluctuation summary...... 46 Table 4: Summary of hydraulic conductivity estimates...... 48 Table 5: Summary of existing numerical groundwater flow models for study area. Bold- italics = model encompasses the Carruthers Creek watershed...... 63
v02: July 25, 2017 Page 1 of 77 TRCA Carruthers Creek – Hydrogeology
List of Figures
Figure 1: Carruthers Creek watershed location and study area. Oak Ridges Moraine Conservation Plan area in orange. Greenbelt area in green...... 6 Figure 2: Study area ground surface topography...... 9 Figure 3: Physiographic regions within the study area...... 10 Figure 4: Environment Canada climate station locations...... 11 Figure 5: Long term study area precipitation and temperature trends...... 11 Figure 6: GSC stratigraphic framework for the Oak Ridges Moraine and south flank (figure from Sharpe et al., 2002)...... 14 Figure 7: Quaternary deposits found within south-central Ontario. Don Formation and York Till are not mapped within the study area (Figure modified from Eyles, 2002)...... 14 Figure 8: Maximum extent of Laurentide ice sheet approximately 18-20,000 years ago that led to deposition of the Newmarket Till...... 15 Figure 9: Deposition of Oak Ridges Moraine between two ice lobes approximately 12- 13,000 years ago (Figure from Chapman and Putnam, 1984)...... 15 Figure 10: Study area surficial geology (from Ontario Geological Survey, 2010). Red line is creek profile location shown on Figure 11...... 16 Figure 11: Carruthers Creek profile. Profile location shown on Figure 10...... 17 Figure 12: Study area bedrock geology (OGS, 2006)...... 19 Figure 13: Study area bedrock topography (from Earthfx Inc., 2009b)...... 20 Figure 14: Study area Quaternary deposit thickness (from Earthfx Inc., 2009b)...... 21 Figure 15: All wells within the ORMGP database classified according to hydrostratigraphic unit, a) shallow flow system wells and b) deep flow system wells. Shallow and deep flow system separated by the Lower Newmarket till. Municipal servicing from Lake Ontario extends from Taunton Road south to Lake Ontario. ...27 Figure 16: MOECC Permit to Take Water permits as of March 2015. ‘Active’ classified permits have expiry dates after 01-Jan-2017...... 28 Figure 17: Summary of available watershed recharge and discharge estimates for the study area. Carruthers Creek watershed baseflow estimate from gauging station HY013 (Carruthers Creek at Achilles; drainage area 26.9 km2; 2008 to 2016) is a minimum of 13 streamflow separation routines (Clarifica, 2002; Piggott et al., 2005; Institute of Hydrology, 1980; Sloto and Crouse, 1996; Rutledge, 1998; Nathan and McMahon, 1990; 1991; Chapman and Maxwell, 1996 and Echhardt, 2005) for the period 2008 to 2014...... 31 Figure 18: Estimated groundwater recharge for the Carruthers Creek watershed. Light blue = 36 mm/year; dark green = 60 mm/year; light green = 90 mm/year; orange = 180 mm/year...... 32 Figure 19: Shallow flow system water table/potentiometric surface. Groundwater flow directions are perpendicular to equipotential contours...... 34 Figure 20: Deep flow system (Thorncliffe Aquifer Complex) potentiometric surface...... 35 Figure 21: Potential vertical groundwater flow directions. Shallow potentiometric surface/water table (Figure 19) minus deep potentiometric surface (Figure 20)...... 36 Figure 22: Study area groundwater monitoring locations...... 38 Figure 23: West-East cross section through north part of Carruthers Creek watershed. Cross section location is shown on Figure 22...... 39 Figure 24: West-East cross section through south part of Carruthers Creek watershed. Cross section location is shown on Figure 22...... 40
v02: July 25, 2017 Page 2 of 77 TRCA Carruthers Creek – Hydrogeology
Figure 25: Claremont Field Centre monitoring nest details. Site monitored by ORMGP and TRCA (PGMN)...... 41 Figure 26: Groundwater levels at the Claremont Field Centre location...... 41 Figure 27: Greenwood Field Centre monitoring nest details. Site monitored by ORMGP and TRCA (PGMN)...... 42 Figure 28: Groundwater levels at the Greenwood Field Centre location...... 42 Figure 29: Groundwater levels for Site EE11 (PGMN W326) Site monitored by ORMGP and TRCA (PGMN)...... 43 Figure 30: Groundwater levels for Site 294 near Claremont. Site monitored by ORMGP...... 43 Figure 31: Groundwater levels from Site 194 southeast of Whitevale near Cherrywood. Site monitored by ORMGP...... 44 Figure 32: Water table elevations in Frenchman's Bay area (Meriano, 2007). Site monitored by ORMGP...... 44 Figure 33: CLOCA PGMN W263 Heber Down groundwater levels. Water table in glaciolacustrine deposits over till on the South Slope Till Plain physiographic region...... 45 Figure 34: Summary of hydraulic conductivity estimates for various stratigraphic units. Data sources listed on Table 4...... 49 Figure 35: Summary of hydraulic conductivity estimates for surficial till deposits...... 50 Figure 36: Summary of hydraulic conductivity estimates for the Lower Newmarket till...50 Figure 37: Streamflow monitoring stations within the study area...... 54 Figure 38: North-south cross section along Salem Road...... 55 Figure 39: Daily average streamflow for TRCA Carruthers gauges...... 56 Figure 40: Average annual streamflow for study area gauges...... 56 Figure 41: Carruthers Creek watershed low flow streamflow survey summary (figure from TRCA, July 2017)...... 57 Figure 42: Durov plot of major ion chemistry from sites within Duffins Creek watershed. Data from MM Dillon Limited, 1990, IWA, 1994a, 1994e, and Gerber, 1999...... 60 Figure 43: Groundwater chloride concentrations from PGMN (TRCA and CLOCA) monitoring wells adjacent to the Carruthers Creek watershed. Groundwater monitoring locations are shown on Figure 22. W263 is from the Lynde Creek watershed and is monitored by CLOCA (PGMN). All other monitors are from the Duffins Creek watershed and are monitored by the TRCA (PGMN)...... 61 Figure 44: Existing numerical flow model locations...... 62
v02: July 25, 2017 Page 3 of 77 TRCA Carruthers Creek – Hydrogeology
1.0 INTRODUCTION
The purpose of this document is to report on the current understanding of the groundwater conditions within the watershed. Carruthers Creek drains an area of 3840 hectares, with headwaters starting at an elevation of approximately 220 m asl and discharging into Lake Ontario in the south at an elevation of 75 m asl. Gaps in data and knowledge will be outlined that will be addressed in the subsequent Phase 2 of this update to the Carruthers Creek Watershed Plan.
1.1 Data Sources
This report is based on existing reports and information largely published by various conservation authorities, consultants, the Ontario Geological Survey and the Geological Survey of Canada. Long-term regional groundwater investigations were initiated in 2001 for much of south-central Ontario by a coalition of conservation authorities and municipal government agencies known as the Oak Ridges Moraine Groundwater Program (ORMGP). Partners include the nine conservation authorities associated with the Oak Ridges Moraine (ORM), the Regions of York, Peel and Durham and the City of Toronto. Since 2001, the ORMGP has conducted data compilation of existing information and collected new data to fill gaps. This document describes the geology and hydrogeology for the Carruthers Creek watershed which occurs at the eastern end of the Toronto and Region Conservation Authority jurisdiction (Figure 1). Hydrogeological information within the Carruthers Creek watershed is limited. A wealth of hydrogeological information exists within adjacent watersheds and is referred to in this report including data from within the Duffins Creek (TRCA jurisdiction) watershed to the west and the Lynde Creek watershed to the east (CLOCA jurisdiction). This information from adjacent watersheds is deemed directly applicable to the hydrogeology of the Carruthers Creek watershed. The study area generally conforms to the Duffins, Petticoat and Frenchmans Bay watersheds to the west of the Carruthers Creek watershed, and the Lynde Creek watershed to the east (Figure 1). The information utilized is managed within the ORMGP analysis system. Further descriptions of the hydrogeology of the adjacent watersheds can be found in TRCA (2007), SooChan (2006) and CLOCA (2007; 2008).
v02: July 25, 2017 Page 4 of 77 TRCA Carruthers Creek – Hydrogeology
The ORMGP analysis system contains data and information related to water resources management and includes borehole and water well information along with climate (Environment Canada) and streamflow (Water Survey of Canada and various conservation authorities) data. The base information for the database is the Ontario Ministry of the Environment and Climate Change (MOECC) water well records. This data has been augmented with other datasets provided by the City of Toronto, the Ontario Geological Survey (OGS; e.g. Baker et al., 1998), the Geological Survey of Canada (GSC) and the various ORMGP partners. The database also includes borehole, piezometer and water well information from consultant reports prepared for the various ORMGP partners. These reports have been scanned (Adobe Acrobat PDF file format) and incorporated into a digital library of collected information. This database is continually being updated with information from the various sources described above. Further information can be obtained at www.oakridgeswater.ca.
v02: July 25, 2017 Page 5 of 77 TRCA Carruthers Creek – Hydrogeology
642000 m 647000 m 652000 m 657000 m 662000 m 667000 m
/
E
Claremont E 0 0 R Stouffvllle ~ \
Lake Ontario N
642000 m 657000 m 662000 m 667000 m + Figure 1: Carruthers Creek watershed location and study area. Oak Ridges Moraine Conservation Plan area in orange. Greenbelt area in green.
v02: July 25, 2017 Page 6 of 77 TRCA Carruthers Creek – Hydrogeology
2.0 PHYSICAL SETTING & GEOLOGY 2.1 Physiography
All watersheds within the TRCA and CLOCA jurisdictions drain southward from the Oak Ridges Moraine (ORM) towards Lake Ontario (75 m asl; Figure 2). There are generally three main physiographic or geologic areas corresponding to the physiographic regions of Chapman and Putnam (1984; Figure 3). These areas include:
• The ORM (and associated hummocky terrain) which occurs immediately to the north of the northern boundary of the Carruthers Creek watershed and consists largely of sand and gravel; • The South Slope occurring to the south of the ORM and largely consisting of till deposits at surface with a localized lacustrine veneer (e.g. Peel Plain); and • Glacial Lake Iroquois sand, silt and clay deposits occurring immediately north of Lake Ontario.
The Carruthers Creek watershed occurs within the South Slope and Glacial Lake Iroquois physiographic regions, south of the Oak Ridges Moraine. The outline of the Oak Ridges Moraine Planning Area, roughly corresponding to the 245 m asl elevation contour, is shown on Figure 2. Note that the ORM is also considered to include the areas of hummocky Halton Till that occur along its southern flank. The approximate Lake Iroquois shoreline location is also shown on Figure 2 and is demarcated here by the 135 m asl ground surface elevation contour.
2.2 Climate
Climate varies across the study area both spatially and temporally with local variation created by such factors as topography, prevailing winds and proximity to Lake Ontario. Human activities can also affect local climate. Deforestation may increase stream and peak flood flows while decreasing evapotranspiration. Urbanization can increase cloudiness, precipitation and extreme winter temperatures while decreasing relative humidity, incident radiation and wind speed (Phillips and McCulloch, 1972). The study area occurs within three climate regions; the Simcoe and Kawartha Lakes, the South Slope and the Lake Ontario Shore (Brown et al., 1980). The climate throughout the study area is largely influenced by Lake Ontario.
Mean daily temperatures for the period 1931 to 1960 range from 5.6 to 6.7 oC in the Simcoe and Kawartha Lakes region of the study area to 6.7 to 7.8 oC along the Lake Ontario shore. In the Simcoe and Kawartha Lakes Region, the mean daily temperature for January (coldest month) is from -8.9 to -7.8 oC. The mean daily temperature for July (warmest month) is 20 oC. For the Lake Ontario Shore, mean daily temperatures for January and July are -6.7 to -4.4 and 20 to 21.1 oC respectively (Brown et al., 1980).
The mean annual precipitation for southern Ontario is 813 mm (1931-1960) compared to the mean value of 724 mm for Ontario (Brown et al., 1980; Ontario Ministry of Natural Resources, 1984; Phillips and McCulloch, 1972). Ontario's mean annual snowfall is 235 v02: July 25, 2017 Page 7 of 77 TRCA Carruthers Creek – Hydrogeology cm (Ontario Ministry of Natural Resources, 1984). Mean annual snowfall for the Great Lakes Region is approximately 203 cm. (Brown et al., 1980; Phillips and McCulloch, 1972). Precipitation over southern Ontario shows little seasonal variation (1931-1960) with growing season (May to September) mean precipitation ranging from 380 mm along the moraine to 356 mm along the Lake Ontario shore (Brown et al., 1980). For the study area the longest recording precipitation gauge is located in Toronto (Station# 6158350; Figure 4) and has been in operation since 1840. The total annual precipitation trend recorded at this station is shown in Figure 5. The average total precipitation recorded is 816 mm/year (n=154), with a maximum of 1,235 mm/year and a minimum of 607 mm/yr.
The mean annual potential evapotranspiration (calculated by the Thornthwaite method) for the period 1931 to 1960 ranges from 584 mm along the moraine to 610 mm along the shore of Lake Ontario (Brown et al., 1980). This compares to estimates of 559 to 584 mm by Phillips and McCulloch (1972) for the Great Lakes Region, also using the Thornthwaite method. The mean annual actual evapotranspiration for the region including the Study Area is 533 mm, reflecting seasonal periods of soil moisture limitations (Brown et al., 1980). Estimates by Phillips and McCulloch (1972) range from 533 to 559 mm, also using the Thornthwaite method. This compares to estimates of 552 mm/year for the period 1962-1979 using the complementary relationship for Toronto International Airport data (Morton, 1983). During periods of soil moisture depletion, estimates of water deficiencies range from 51 mm along the moraine to 76 mm along Lake Ontario. Estimates of water surplus during periods of soil moisture capacity range from 279 mm along the moraine highlands to 330 mm along the north and south flanks of the moraine. This water surplus represents that available as surface runoff and/or groundwater recharge (Brown et al., 1980).
v02: July 25, 2017 Page 8 of 77 TRCA Carruthers Creek – Hydrogeology
Easting (m ) Legend x Ground Surface-orm100mv5-masl (MNR v2) Map Scale in metres ( 1: 163229) e--1.1... s~ ·'t,. P ,o :$'ooco ·•oo ORM Planning boundary ,oo 200 :JOO ... " ... 0 4000 8000 - Lake Iroquois - 135 mas! e-_1.,... ,_.,3,5 $""', $11:,c, • 1:,e Projection: UTM NAD83 Zon e17 Date (y/m/d): 2017-02- 16 TRCA· Carruthers- Landscape
Figure 2: Study area ground surface topography.
v02: July 25, 2017 Page 9 of 77 TRCA Carruthers Creek – Hydrogeology
642000 m 647000 m 652000 m 657000 m 662000 m 667000 m J;icJ:i omberg Clay Plains !' 7' ~ ~Ji'oe \ es E ~,o~ 0 0 0 o-a.¥- ~ .· ~ ~" s,091_\ Claremont E sou\" E uffville 8 i Brooklin, ~ 8 ~ \ ~ ~
E E 0 0 0 0 0 0 ~ ~ ~ ~ ~.,. ~401 \>ee\ Whitby Markham E E 8 8 0 ~ § "'.. "'..
Lake Ontario N 5000 m t\'if'l 411'\ + 642000 m 647000 m 652000 m 657000 m 662000 m 667000 m Figure 3: Physiographic regions within the study area.
v02: July 25, 2017 Page 10 of 77 TRCA Carruthers Creek – Hydrogeology
/ • I
LAKE ONTARIO
620000 63()()0() 640000 650000 660000 670000 690000 700000 Ea5ling (m)
Legend Map Scale in metres (1 ;381902) ORM P lanning boundary • climate stations - all • climate $l$tiOn$ - active 0 10000 20000 O c limate - long ter m stations Projection: U T M NAD83 Zone17 x Lake Iroquois 135 masl Oate { y/m/ d): 2017-07-18 - 00.--..r ~ S'lllil 1:,s 5,._~ 1 S~ 138 Can-uthers - climate s tation locations
Figure 4: Environment Canada climate station locations.
Precipitation and Air Temperature (Toronto 6158350 to 2002; Toronto City 6158355 > 2002; Buttonville A 615HMAK; Oshawa WPCP 6155878) 1250 ,-,--,--,-~ --,---;::=s===:=;:=;::;;:~=====::::;--,-,--,--,-,--,--,-7 -tr-Toronto • Precipitation - Buttonville A - Precipitation --Oshawa \!\oPCP - Precipitation 1150 +----+---+---- - + -_., - Tor onto - T e"l)erature - • - Buttonville - Temperature - .. - Oshawa \!\oPCP - Temperature I 1050 ------t ------10 yearmovingaverage -Toronto r--+---+---r--½·· ------______1 C i = ~~~=:~:::~~:::;:::~:~:~p tJ._
I/
, I I~:'. .... ,~}~·1·· r~•~*H~~:-~.-~r=._~t_:~ ----+-) ;·--!- ,+, J 0- • 12.0 .!:!. . . 11 .5 ~ 11 .0 i:l 550 +----+---+---+----+---+---l---+--+--~f---+--+------l---+--+----+-~:\1~ ----+-- ft------10.5 ~ ~ 10.0 a. ! ! .~ ~ • ?. +\ i :i: : " ~· : E 9.5 ,!! ----+---+------+---+---.-.---- ·------ti ! •.-;;----~-iii :.\ _:·~ tN~ _.t:..J..\!.:... ,1 -~«i~J-1~4!~.----- 9.0 85 < ;;; 8.0 : . L . i /t .:t,YA.PwW :. ~ ··· ftts:~·Q ~; :·~.;~ : ~ ,; -r ~--- : • , .M ·:~ ' :l 1------, ~-;,-,- --~-:r.P + ---- ..,.-T- --·,-;n;-:--- ... ,; .. --.--~ +-i·t•tt 11 ---11 ---~------7.5 C ~···"· ~L :'•t.t~· .,.. . ··•·· ·. ,. ,, • .. ., , • 1111 ·, .,..;; , 7.0 .. _. ,, l ,\r.~.lij ' : •I , :, •' i '• •' ~'J • ~ 6.5 .. ~ 1) ; ·.; l • 6.0 ~ -~-J-r -~t --1--w:Lf--~------_j ~ 5.5 ~ 5.0
1840----~------~----~~----~--~----~-----~- 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 20204 .5
Figure 5: Long term study area precipitation and temperature trends. v02: July 25, 2017 Page 11 of 77 TRCA Carruthers Creek – Hydrogeology
2.3 Geology
The geologic units present within the Carruthers Creek watershed are regionally extensive throughout much of south-central Ontario. This section will describe the regional geologic setting and then place the Carruthers Creek watershed into context. The geology of south-central Ontario generally consists of Quaternary sediments infilling a fluvial valley system (Laurentian valley) incised upon the bedrock surface. This bedrock valley system drained the upper Great Lakes basin to the St. Lawrence River, which relative to the study area extends from Georgian Bay to Toronto near the mouths of the Humber and Don Rivers, and through Lake Ontario (Spencer, 1890). The sediments overlying bedrock consist of a sequence of glacial and interglacial (lacustrine/fluvial) units recording deposition over approximately the last 135,000 years. This sedimentary package ranges in thickness from zero (bedrock outcrop) to 270 m within the Laurentian bedrock valley system. The Carruthers Creek watershed is situated over the northern flank of the Laurentian valley system.
The various geologic deposits and their characteristics will be described in more detail in subsequent sections. It should be noted that there is still some disagreement and considerable discussion and research regarding the stratigraphy present within the study area. Historical work (e.g. White, 1975; Karrow, 1967) is still being re-interpreted by various groups including the OGS and the GSC (e.g. Barnett et al., 1998; Sharpe et al., 2004).
The stratigraphic framework for the study area is well established from previous work (Karrow, 1967; White, 1975; Sharpe et al., 1999). The GSC has constructed three- dimensional geologic surfaces which group the pertinent geological deposits into five major units including (Figure 6);
1. Halton Till (youngest; Russell et al., 2002a) 2. Oak Ridges Moraine Deposits (Russell et al., 2002b) 3. Newmarket Till (Sharpe et al., 2002a) 4. Lower Deposits (Sharpe et al., 2002b) 5. Bedrock (oldest; Brennand et al., 1997).
Regional unconformities are interpreted to occur upon the bedrock and Newmarket Till surfaces. The GSC have also provided preliminary information on the locations of tunnel channels that trend roughly north-south to northeast-southwest in southern Ontario (Russell et al., 2003).
The stratigraphic interpretation by the ORMGP has split the Lower Deposits of the GSC into three units including the Thorncliffe Formation, Sunnybrook Drift and the Scarborough Formation to incorporate the geologic understanding from historical Toronto-area investigations (Karrow, 1967; Eyles and Eyles, 1983). The ORM and underlying sediments are late Pleistocene in age and unconformably overlie thin Paleozoic bedrock platform strata. Ordovician shale underlies the thick glacial sediments of the study area.
Pleistocene glacial sediments (~last 2 million years) within the study area are up to 200 m thick and consist of glacial and interglacial deposits formed within the last 135,000 v02: July 25, 2017 Page 12 of 77 TRCA Carruthers Creek – Hydrogeology years (Eyles, 2002; Karrow, 1989). The last glaciation, termed the Wisconsin, started approximately 100,000 years ago (Eyles, 2002). Recent summaries describe the glacial history of southern Ontario (Barnett et al., 1991), the ORM (e.g. Barnett et al., 1998) and till plains south of the ORM (Martini and Brookfield, 1995; Boyce et al., 1995). Quaternary glacial and non-glacial sediments are exposed in the southern part of the study area along the Lake Ontario bluffs and in the Don Valley brickyard (e.g. Karrow, 1967; Brookfield et al., 1982; Eyles and Clark, 1988) and underlie the ORM (Duckworth, 1979; Sado et al., 1984; Eyles et al., 1985). This complex package generally consists of till, glaciolacustrine sand, silt, clay and diamicton and includes Illinoian-age till and warm- climate interglacial sediments overlain by early to middle Wisconsinan age (25-90,000 years ago) glacial lake sediments (Karrow, 1967). Figure 7 summarizes the Quaternary sediments generally found within the study area.
The last major ice advance (Late Wisconsinan; ~20,000 years BP) was from the northeast (Figure 8) and along the axis of the Great Lake basins. During this interval the ice deposited a thick widespread till sheet or amalgamated sheets (Newmarket Till). This till overlies thick lower deposits and both sequences continue under the ORM. This regional till sheet is variable in thickness (Sharpe et al., 2002a) and has been eroded by meltwater to form a regional unconformity consisting mainly of drumlins and a network of channels (Barnett, 1990). The ORM rests on this eroded terrain and formed approximately 12,000-13,000 years ago (Gwyn and Cowan, 1978).
The ORM occurs as thick stratified sediments, partly capped by thin Halton Till along its southern flank. The ORM sediments were deposited rapidly in a glacial lake (e.g. Gilbert, 1997; Barnett et al., 1998) set in a re-entrant or cavity between thick ice of the Laurentide Ice Sheet to the north and low-relief ice occupying the Lake Ontario basin to the south (Figure 9). ORM deposits may be part of a larger system of ice-controlled meltwater deposition during final deglaciation that includes stratified moraines west of the ORM (Gwyn and Cowan, 1978). The youngest deposits consist of glaciolacustrine sediments that form a thin veneer over the Halton and Kettleby till units. The location of these deposits is shown on the surficial geology map provided as Figure 10.
In summary, the stratigraphic framework used for this study includes eight geologic units including:
1. Glaciolacustrine Deposits (sand, silt and clay); 2. Halton Till; 3. Oak Ridges Moraine/Mackinaw Interstadial Deposits; 4. Newmarket Till; 5. Thorncliffe Formation; 6. Sunnybrook Drift; 7. Scarborough Formation; and 8. Bedrock.
The Don Formation and underlying York Till (Figure 7) have not been mapped regionally because of the paucity of deep detailed information that would be necessary to delineate these deposits. The geologic deposits mapped within the Carruthers Creek watershed are shown on a cross section creek profile in Figure 11.
v02: July 25, 2017 Page 13 of 77 TRCA Carruthers Creek – Hydrogeology
Oak Ridges Moraine sediment
Halton TIii
Channel sediment
Lower sediment
Figure 6: GSC stratigraphic framework for the Oak Ridges Moraine and south flank (figure from Sharpe et al., 2002). . > ..~
Glaciolacustrine Deposits (-12,500) Halton Till (-13,000)
Oak Ridges Deposits Late Wisconsin Glacial Complex Mackinaw lnterstadial (-13,300)
Newmarket (Northern) Till (-20,000>
Thorncliffe Fm. (-45,000) Early-Mid Wisconsin includes Meadowcliffe Diamict Glacial Lake and Seminary Diamict Deposits
______Sunnybrook Drift
Early W1scons1n Scarborough Fm. (c. 60,000) Delta
Don Formation (c. 80,000) ~-----_ ! ':'"~Till (1 35,000)
Paleozoic Bedrock
Figure 7: Quaternary deposits found within south-central Ontario. Don Formation and York Till are not mapped within the study area (Figure modified from Eyles, 2002). v02: July 25, 2017 Page 14 of 77 TRCA Carruthers Creek – Hydrogeology
60'W so·~· 0,, ..,,, ,.· ,,,.10001an -?' I i 150(}mj 120'W . .,, 70'W Basoo 00 !lala 01 R. F. F&\1,. Ghleill! aoo· PleiSlrxer,e Geology, JOl'in Wiley 11 sons, r-:ew YO! •
Figure 8: Maximum extent of Laurentide ice sheet approximately 18-20,000 years ago that led to deposition of the Newmarket Till.
0 100 km
Figure 9: Deposition of Oak Ridges Moraine between two ice lobes approximately 12- 13,000 years ago (Figure from Chapman and Putnam, 1984). v02: July 25, 2017 Page 15 of 77 TRCA Carruthers Creek – Hydrogeology
642000 m 647000 m
E Markham 0 0 I0
E E 0 0 0 0 0 0
~ ~ ~ f Lake Ontario N 5000m + 642000 m 657000 m 662000 m 667000 m
Coarse textured glaciolacustrine deposits - Modern alluvial deposits
Coarse textured lacustrine deposits - Older alluvial deposits
[- Eolian deposits - Organic deposits
- Fine textured glaciolacustrine deposits - Paleozoic bedrock
- Glaciofluvial deposits - Till - Clay to silt textured till - Ice contact stratified deposits - Till - Stone poor, sandy silt to silty sand till
- Man-made deposits - Till - Undifferentiated older tills
Figure 10: Study area surficial geology (from Ontario Geological Survey, 2010). Red line is creek profile location shown on Figure 11.
v02: July 25, 2017 Page 16 of 77 TRCA Carruthers Creek – Hydrogeology
7th Cone.
Hwy. 7 5th Cone.
Lake Iroquois shoreline
HY089 - T RCA s tre am gauge
T a u n ton Rd . HY090 -T RCA strea m gauge
Rossland Rd .Kingston Rd. Hwy. 4 0 1 HY 0 13 - TRCA s tre a m gauge Bayly S t. Lak e O n ta(
I 0 5000 10000 15000 $ectlon O!stanee (m) Logond: -~c~nt d,ep0$,it$ (01,.n h {un rn,odel ; O&e 2007) Map scare (in tnetres) - Halton Till - Oak Ridges MOf'ilinofMIS (aquifer) Toronto and Regio n Conservation A uthority - Lower Newmo,ket Tm O 2000 4000 Thomcliffe Fm. (aquife r) ven ical exaggeration: 60X Carruthers Creek profile Notes: - Sunnybrook Drift - Projection: UTM NAD83 Z one 17 $(.{ar bo(OU$h F rn . (.)qi.rifOt) Top of Bedrock (Durham modet; Dec 2007) - Date (y/mld): 201 7-07--07
Figure 11: Carruthers Creek profile. Profile location shown on Figure 10.
2.3.1 Bedrock
Bedrock within the study area consists of shale of the Upper Ordovician Blue Mountain Formation (Figure 12; Johnson et al., 1992). These rocks are between 505 and 438 million years old and were deposited in an ancient sea known as the Iapetus Ocean which formed following the breakup of the supercontinent Rodinia approximately 600 million years ago. The progression from the older shale rocks to the younger dolostone (east to west) provides evidence for a progression from deeper water conditions to shallow, reef forming areas. The Ordovician limestone and shale lie unconformably upon PreCambrian shield rocks 1.45 to 1.1 billion years old that are at least 70 km thick. The sedimentary rocks dip to the west at approximately 6m/km (Johnson et al., 1992).
The Paleozoic surface, prior to Pleistocene glaciation, has been deeply eroded as part of an ancient mid-continent river system (Laurentian valley; Eyles, 2002; Eyles et al., 1993). This surface is a regional unconformity separating rock from sediment. The general location of valleys on this surface have been mapped previously on a regional basis (e.g. Eyles et al., 1993) and for various map sheets within or near the study area by the Ontario Geological Survey (Holden et al., 1993a; 1993b; 1993c; 1993d; Karrow, 1970; 1992; Rogers et al., 1961; Sharpe and Clue, 1978; White, 1975). The best documented of these buried valleys, the Laurentian valley, extends from Georgian Bay v02: July 25, 2017 Page 17 of 77 TRCA Carruthers Creek – Hydrogeology to Lake Ontario (Spencer, 1881) and is buried by sediment up to 200 m thick. Beneath the ORM, the geometry of the bedrock surface is poorly constrained, as few wells intersect bedrock. Investigations using location-corrected water-wells, hydrogeological borehole data, and seismic reflection profiles indicate a trunk and tributary valley system (Brennand et al., 1997). These bedrock valleys may contain productive aquifers. It is also important to remember that this bedrock valley system was probably altered by processes associated with successive glacial and interglacial periods that have occurred throughout the Quaternary Period which began approximately 1.8 million years ago.
The interpreted bedrock topography is shown on (Figure 13). Two main outlets of the Laurentian bedrock valley system are interpreted along the Lake Ontario shoreline near Humber Bay, and east of the Toronto Islands following the original Don River channel prior to human re-routing through the Toronto harbour area. The bedrock topography within the Carruthers Creek watershed declines from a high of 130 m asl in the headwater area to a low of 40 m asl along the Lake Ontario shoreline. The Quaternary sediment thickness overlying bedrock within the Carruthers Creek watershed ranges from a high of 125 m in the northern part of the watershed to a low of approximately 3 m in the south (Figure 14). South of the Lake Iroquois shoreline (Whitevale Road/5th Concession Road) the Quaternary sediment thickness is interpreted to be less than 35 m. There are no known or mapped bedrock outcrops within the Carruthers Creek watershed.
v02: July 25, 2017 Page 18 of 77 TRCA Carruthers Creek – Hydrogeology
642000 m 647000 m 652000 m 657000 m 662000 m
E E 0 0 0 \i\(\ 0 0 0 ~ \t,O\)(\ ~ ~" ~" 13\ue /1,, )
Claremont '
S uffville A ' 0 \j I
E 0 0 0 ~ ~
E I
E 0 I I 133-i . 3,(\ Geo<~' Lake Ontario N O 5000 m + 642000 m 652000 m 657000 m 662000 m 667000 m Figure 12: Study area bedrock geology (OGS, 2006).
v02: July 25, 2017 Page 19 of 77 TRCA Carruthers Creek – Hydrogeology
I
fz
Easting (m )
Legend Map Scale in metres (1 :205260) ORM P lanning boundary - Lake Iroquois - 135 masl o,,,,.m,..,u,i,e&i1o11· 1~5 8,:,0,ii,::1 6~ 1:M 0 5000 10000 ~ g!!l,.~~~~l;~~:~-» ~del; Dec 2007} Projection: UTM NAD83 Zone17 ,.. ""' Oate {y/m/d): 201 7-07-20 Can1.1thers - bedrock to pography
Figure 13: Study area bedrock topography (from Earthfx Inc., 2009b).
v02: July 25, 2017 Page 20 of 77 TRCA Carruthers Creek – Hydrogeology
I
fz
Easting (m )
Legend Map Scale in metres (1:205260) ORM P lanning boundary - Lake Iroquois -135 masl ~Un,t&a,11· 1:,5 6111'~1 61f19 , ,a 0 5000 10000 Quaternary sediment ls opach (m; Durham model: Dec 2007) ~ 1.i.. ~ti, $-., 10 $11» r.10 Projection: UTM NAD83 Zone17 Oa te (y/mld): 2017-07-20 Carn.1thers - Quaternary sediment thickness
Figure 14: Study area Quaternary deposit thickness (from Earthfx Inc., 2009b).
2.3.2 Scarborough Formation
The Scarborough Formation marks the start of the Wisconsinan glaciation which started approximately 100,000 years ago. The Scarborough Formation deposits are interpreted as a fluvial-deltaic system fed by large braided melt-water rivers draining from an ice sheet depositing prograding organic-rich (peat) sands over silts and clays (Karrow, 1967; Kelley and Martini, 1986; Eyles, 1997). The lower prodelta silts and clays are up to 60 m thick at the Scarborough Bluffs along Lake Ontario and are believed to be in transitional contact with the muds of the underlying Don Formation (Eyles, 1987). The upper sands are channelized in some locations, possibly as a result of fluvial erosion due to fluctuating lake levels. The delta is considered to extend over 200 km2 and was deposited by a large river flowing from Georgian Bay along the Laurentian River channel to ancestral Lake Ontario. Lake levels must have been up to at least 45 to 60 m higher than present perhaps indicative of some type of ice damming to the east.
2.3.3 Sunnybrook Drift
The Sunnybrook Drift unit was deposited in close proximity to an ice sheet as it finally reached the study area about 45,000 years ago. The Sunnybrook Drift is interpreted to be a clast-poor mud (silt and clay) deposited on the floor of a glacially dammed lake v02: July 25, 2017 Page 21 of 77 TRCA Carruthers Creek – Hydrogeology approximately 100 m deeper than the modern Lake Ontario (Eyles, 2002). Boulders and pebbles are rare and are interpreted to result from melting icebergs. An alternate explanation is that this unit consists of multiple diamicton (till-like) beds resulting from the interfingering of ice marginal flow tills and subglacial deformation and lodgement till (Barnett, 1992). Another interpretation is that this unit is a deformation till resulting from glacial overriding of lake clays (Hicock and Dreimanis, 1989) and has been identified near Woodbridge as a pebble-free mud (White, 1975). The Sunnybrook Drift is generally 10-20 m thick and is thickest where it fills valleys on the tops of the underlying units such as occurs at Bluffers Park Marina area (Highland Creek watershed shoreline area) and near High Park.
2.3.4 Thorncliffe Formation
The Thorncliffe Formation is interpreted to respresent deposition in a large lake extending from Georgian Bay to Lake Ontario, bounded by the Canadian shield to the northeast and the Niagara Escarpment to the west. Coarser-grained deposits of sand and gravel represent glaciofluvial deposition in near shore environments. Deeper water glaciolacustrine deposits include silt, silty sand and clay deposited by glacial meltwaters entering a deep, ice-dammed ancestral Lake Ontario. The basal part of this unit is often marked by silt-clay rhythmites. This unit was deposited approximately 45,000 years ago (Eyles, 2002; 30,000 to 50,000 years ago according to Barnett, 1992). The pebbly silt and clayey silt units are known as the Seminary and Meadowcliffe Diamict units where they occur along the Scarborough Bluffs and are believed to have limited extent north of the bluffs (Barnett, 1992; Eyles and Eyles, 1983; Karrow, 1967). The Thorncliffe Formation within the Carruthers Creek watershed is predominantly glaciolacustrine silty sand as interpreted from OMOECC water well records. The Thorncliffe Formation is characterized by significant facies changes over short distances, generally on the kilometer scale (Interim Waste Authority Limited, 1994a-e; MM Dillon Limited, 1990).
2.3.5 Newmarket Till
The Newmarket Till (sometimes referred to as the Northern till - Eyles, 1997; Boyce, 1997; Boyce et al, 1995; Gerber, 1999; Gerber and Howard, 1996; 2000; 2002; Gerber et al., 2001 or Lower Leaside or Lower Halton Till – Karrow, 1967) is a dense, over- consolidated diamict deposited by the Laurentide ice sheet when it was at its maximum extent approximately 18-20,000 years ago. The matrix is predominantly calcite- cemented sandy silt to silty sand with a clast content mainly comprised of limestone with a minor component of Canadian Shield rocks. The Newmarket Till can be traced as a stratigraphic marker across the entire study area. Regionally the Newmarket Till contains breaches where it has been eroded by meltwater activity (“Tunnel Channels”; Shaw and Gilbert, 1990; Brennand and Shaw, 1994). Based on current information tunnel channels do not occur within the Carruthers Creek study area.
The structure of the Newmarket Till is important to understanding its permeability variation which will be described more fully later (Section 3.3.1 Hydraulic Properties). The Newmarket Till is a massive, stony (3-10 %) and consistently dense silty sand diamicton up to 60 m in thickness (generally 20 to 30 m thick) and has been traced lithologically beneath the moraine (e.g. Gwyn, 1976; Barnett et al., 1991; Sharpe et al., 2002a). The top of the Newmarket Till is generally less than 300 m asl beneath the Oak v02: July 25, 2017 Page 22 of 77 TRCA Carruthers Creek – Hydrogeology
Ridges Moraine and dips southward towards Lake Ontario. It contains thin, 2-5 cm thick, interbeds of sand and silt, boulder pavements and fractures and joints. It also contains small injections, dykes, breccia and rafts from lower sandy beds. Discontinuous sand beds up to 1-2 m may also be present. In rare instances, it contains thin rhythmites or isolated clay laminae. The Newmarket Till is subglacial in origin with incremental till accumulation, periodically interrupted by meltwater scours and localized deposition of sand and silt (Boyce et al., 1995; Sharpe et al., 2002a). The Newmarket Till is characterized by high seismic velocities in downhole seismic logs obtained over wide areas, and the contrast in velocities between it (2000-3000 m/s) and adjacent sediments (1500-2000 m/s) makes it a prominent reflector on seismic profiles (Pullan et al., 1994; Boyce et al. 1995; Pugin et al., 1999).
2.3.6 Oak Ridges Moraine Deposits
Early work on the ORM has been summarized by Duckworth (1979), Gwyn and Cowan (1978) and Chapman (1985). These investigations have relied on analysis of water wells, earlier geologic mapping (e.g. Deane, 1950), and later work by the Ontario Geological Survey (Watt, 1957; 1968; Karrow, 1967). This geologic mapping was important for regional hydrogeological assessments by Haefeli (1970), the Ontario Ministry of Environment (MOE) (Turner, 1977; 1978; Sibul et al., 1977; Ostry, 1979) and others (e.g. Howard and Beck, 1986; Howard et al., 1997). Much of this earlier geologic work has been updated by the GSC (Russell et al., 2002b) with additional subsurface interpretations provided by the ORMGP project team.
The ORM is an extensive stratified sediment complex 160 km long and 5-20 km wide, arranged as four sediment wedges, each widening westward. The wedges sit distal to large channels extending from Albion Hills, Uxbridge, Pontypool and Rice Lake (Sharpe et al., 1994; Barnett et al., 1998). Most of the study area lies within the Albion Hills and Uxbridge Sediment Wedge which contains a number of delta fan features with two associated sand plains (Goodwood and Ballantrae) as well as moraine features. The ORM may be more extensive (~ 5km) and may reach thicknesses of 150 m in the subsurface, particularly beneath younger till sediments which flank the moraine. The lower contact of the ORM sits on a regional unconformity upon the Newmarket Till and lower sediment. ORM sediments occur primarily within fan-shaped bodies on the scale of 10-100 m thick, 100-5,000 m long and 10-1000 m wide. These sediments are arranged from coarse to fine in a downflow direction and vertically upsection. Core logging shows that moraine sediments may consist of 2-3 fining-upward sequences (Gilbert, 1997; Russell et al., 1997). Rhythmically interbedded fine sands and silts are the dominant sediments, but coarse, diffusely-bedded sands and heterogeneous gravels are prominent locally, at the apex of fans and at depth in channels. Clay laminae are also present locally. ORM sediments have predominant NE-SW to E-W paleoflow indicators. The deposits are interpreted as glaciofluvial, transitional to glaciolacustrine subaqueous fan, and delta sediments. They were deposited in a glacial lake ponded between two glacial ice lobes (Simcoe and Ontario Lobes) and the Niagara Escarpment to the west approximately 12-13,000 years ago during the Mackinaw Interstade (Figure 9).
The formation of the Oak Ridges Moraine progresses through four major stages, beginning with high energy subglacial channels depositing coarse gravels in east west trending eskers. This was followed by a second stage of deposition forming high energy v02: July 25, 2017 Page 23 of 77 TRCA Carruthers Creek – Hydrogeology subglacial fans. This was followed by glacial fan and delta formations emerging with the deposition of fine sands as the ice receded. The last depositional phase was a lower energy environment with ice marginal deposits including glaciolacustrine stratified sediments and debris flow deposits. This complex sedimentary sequence consists primarily of granular deposits (Barnett et al., 1998).
Generally, the Oak Ridges Moraine deposits are less than 90 m thick and thin along the north and south flanks of the moraine where they are covered by surface tills. The extent of the ORM sediments within the subsurface along the flanks is more extensive than mapped by Turner (1978). The borehole and water well record database show the presence of significant sand bodies between the underlying Newmarket Till and overlying Halton Till from the last glaciation. These sand bodies are not present everywhere. Note that the Oak Ridges Moraine sediments distal from the moraine itself are considered to be Mackinaw Interstadial sediments with the degree of hydraulic connection to the Oak Ridges Moraine decreasing or nominal remote from the moraine. Mackinaw Interstadial sediments generally only occur locally within areas of low topography upon the surface of the underlying Newmarket Till.
2.3.7 Halton Till
The latest glacial ice advance over the southern part of the study area occurred from the Lake Ontario Basin about 13,000 years ago and resulted in the deposition of the Halton Till from the Lake Ontario Ice. Note that for this study the Halton Till is believed to form the surficial till unit extending southward to the Lake Iroquois shoreline. This interpretation extends the till further south than the GSC interpretation (Russell et al., 2002a).
The Halton till is texturally variable but is generally a sandy silt to clayey silt till interbedded with silt, clay, sand and gravel (Russell et al., 2002). In some areas it is very clay-rich where the Halton ice has overridden glaciolacustrine deposits. The Halton Till is typically 3 to 6 m thick but locally it exceeds 15 to 30 m in thickness (Russell et al., 2002; White 1975). On the southern flanks of the Oak Ridges Moraine it has overridden the granular Oak Ridges Moraine deposits extending as far north as Oak Ridges in Richmond Hill and to the Vandorf Sideroad near Stouffville.
2.3.8 Surficial Glaciolacustrine Deposits
The uppermost regionally significant surficial geologic unit consists of a sequence of glaciolacustrine deposits that form a veneer over the underlying Halton and Newmarket tills. These deposits vary from near shore sands and gravel beach deposits of the Lake Iroquois shoreline located within the southern part of the study area, to the fine sands, silts and clays of glaciolacustrine ponding that occur north of the Lake Iroquois shoreline. These sediments generally form a thin veneer over the underlying deposits, although locally they can be several meters thick. These units represent local ponding of water, or higher water levels in Lake Ontario and Lake Simcoe, following retreat of the glaciers approximately 12,500 years ago. For example, Glacial Lake Iroquois (ancestral Lake Ontario) water levels were at least 40 to 60 m higher than present due to ice blockage and damming of water along the St. Lawrence River (Anderson and Lewis, 1985; Eyles, 1997). Note that shoreline elevations are slowly changing as a result of postglacial glacio-isostatic rebound (Eyles, 1997). v02: July 25, 2017 Page 24 of 77 TRCA Carruthers Creek – Hydrogeology
3.0 HYDROGEOLOGY
This section builds on the geologic framework provided previously and describes the present understanding of how water flows through the various geologic units. The discussion in this section starts with a description of the hydrostratigraphic framework and then describes how groundwater enters the subsurface (recharge), how this water moves through the subsurface (groundwater flow) and where groundwater leaves the subsurface or intersects with the ground surface (groundwater discharge). Also included in this section are brief descriptions of the available groundwater quality data and groundwater use. Phase 2 of this Carruthers Creek Watershed Plan update will expand on the groundwater quality information presented here, and also conduct numerical groundwater flow system modelling to look at water budget implications for various land use scenarios.
3.1 Hydrostratigraphy
Hydrostratigraphy is different than the geologic stratigraphy in that hydrostratigraphic layers represent a classification of the geologic units into aquifers or aquitards as units with similar hydraulic properties. The hydrostratigraphic classification for this study is included in Table 1 and includes three aquifer systems or complexes – the Oak Ridges, Thorncliffe and Scarborough Aquifer Complexes. As with the geologic units, all hydrostratigraphic units are not present everywhere throughout the study area. For example, within the Carruthers Creek watershed to Oak Ridges Aquifer Complex pinches out within the northern half of the watershed. Also of note is that the term ‘Complex’ is used for the various aquifer units because all soil units present within a geologic Formation (e.g. Scarborough Formation) range from gravel and sand to clay deposits and are not strictly aquifer material. The Lower Newmarket Till (aquitard) is a key hydrostratigraphic unit because it separates the shallow part of the groundwater flow system from the deeper part of the groundwater flow system.
Table 1: Hydrostratigraphic units within the Carruthers Creek watershed. Geologic Unit Hydrostratigraphic Unit Glaciolacustrine and Recent Halton Till Halton Aquitard Oak Ridges Oak Ridges Aquifer Complex Moraine/Mackinaw Interstadial Lower Newmarket Till Newmarket Aquitard Thorncliffe Formation Thorncliffe Aquifer Complex Sunnybrook Drift Sunnybrook Aquitard Scarborough Formation Scarborough Aquifer Complex Bedrock Bedrock Aquitard Note: The Lower Newmarket Till aquitard is a regional aquitard that separates the shallow part of the flow system from the deep part of the flow system.
v02: July 25, 2017 Page 25 of 77 TRCA Carruthers Creek – Hydrogeology
3.1.1 Groundwater Use
There are no municipal water supplies from groundwater situated within the Carruthers Creek watershed. The southern half of the watershed south of Taunton Road is municipally serviced from a lake-based (Lake Ontario) supply (TRCA, 2007). North of Taunton Road water supplies are obtained from private wells. The estimated population in the northern part of the watershed on private well supply is 638 based on 2001 census data from Statistics Canada (Gartner Lee Limited, 2003). Assuming a per capita use of 175 L/capita/day, the total estimated domestic groundwater consumption rate for the unserviced area is 112 m3/day (Gartner Lee Limited, 2003). All three aquifer complexes are utilized by private wells for household water supplies plus agricultural and golf course irrigation purposes. The shallow Oak Ridges Aquifer Complex pinches out within the northern part of the watershed and does not exist south of the Lake Iroquois shoreline. South of the Lake Iroquois shoreline prior to servicing by municipal lake- based supply, historical wells obtained water from largely water table conditions within the Thorncliffe or Scarborough Aquifer Complexes which occur close to the ground surface. North of the serviced area (Taunton Road), the majority of water wells within the database are screened within the deep part of the groundwater flow system (Figure 15).
Any water takings that exceed 50,000 L/d must obtain a Permit to Take Water (PTTW) from the Ontario Ministry of Environment and Climate Change. PTTW locations as of March 2015 are shown on Figure 16. Active groundwater taking permits situated north of the Lake Iroquois shoreline are related to golf course irrigation. Active surface water permits situated south of the Lake Iroquois shoreline are also related to golf course irrigation. Active permits with takings listed as from both surface water and groundwater are associated with Highway 407 construction.
v02: July 25, 2017 Page 26 of 77 TRCA Carruthers Creek – Hydrogeology
..,..., ...... M0000 ..,soo Legend; e$.!SOO '55000 ..,soo Legend: Lower Newn,arket 1111 wells • Thomd1ffb Fm wttllt. Glnc,iol.~U5trinc well& - ORM Planning Bo undary - O RM Planning Boundary • Htllton Til wclb ~ Sunl"lybfook Otlft wll!llla • M ISCJORAC W(tls • &arborough F,l'I ~!bi ... LA!<.!~~~7,_!3.t,~a~ ,_ Oat• (y/ mld): 2017-07-20 0 Bftd Figure 15: All wells within the ORMGP database classified according to hydrostratigraphic unit, a) shallow flow system wells and b) deep flow system wells. Shallow and deep flow system separated by the Lower Newmarket till. Municipal servicing from Lake Ontario extends from Taunton Road south to Lake Ontario. v02: July 25, 2017 Page 27 of 77 TRCA Carruthers Creek – Hydrogeology 650000 655000 660000 665000 Legend: Easting (m ) + moeecc pttw o moeecc pttw - active - ORM Planning Boundary • moeecc pttw - active - gw "' moeecc pttw - active - sw Date (y/m/d): 2017-07- 11 - Lake Iroquois -135 masl - Contour Line St.Jrt· 135 Step· 1 S top· 136 Carruthers - PTTW Figure 16: MOECC Permit to Take Water permits as of March 2015. ‘Active’ classified permits have expiry dates after 01-Jan-2017. v02: July 25, 2017 Page 28 of 77 TRCA Carruthers Creek – Hydrogeology 3.2 Groundwater Recharge Recharge has been estimated using a number of different methods throughout the study area and has yielded a wide range of values. A major recharge area occurs to the north of the Carruthers Creek watershed along the Oak Ridges Moraine where unit rates for surficial sand and gravel deposits can exceed 300 mm/yr. The hummocky terrain present over much of this area precludes the formation of stream channels. Any precipitation that doesn’t evapotranspire or evaporate will predominantly infiltrate or form local runoff that collects in hummocks, but ultimately much of this water infiltrates. Some of this infiltration over the ORM may flow southward into the Carruthers Creek watershed as shallow groundwater flow within the Oak Ridges aquifer complex. Much of the south flank of the ORM is covered with till or till with a lacustrine veneer. Unit recharge rates for these deposits are less than half of those on the ORM (~ 100 to 150 mm/year). Recharge through the surficial till is enhanced where the topography is hummocky along the ORM and is reduced to negligible along the immediate south flank of the ORM planning boundary (e.g. Richmond Hill and Stouffville) where the Oak Ridges Aquifer Complex (ORMAC) is confined by the overlying till. In these areas vertical hydraulic gradients are upwards between the ORMAC and the water table with minor recharge occurring to sand bodies contained within the till. Deposits of the ORM do not occur at surface within the Carruthers Creek watershed but they do occur beneath the South Slope Till Plain locally within the northern half of the study area (see Figure 11 , Figure 23 and Figure 38). The southern part of the study area contains Glacial Lake Iroquois deposits exhibiting different recharge rates depending on the deposits which range from lacustrine gravel to clay and till. The Lake Iroquois beach deposits of sand and gravel will have the highest unit recharge rates for this area except for where upward vertical gradients occur along the break in topographic slope. A summary of available recharge estimates for different surficial geologic deposits applicable to the Carruthers Creek watershed are summarized in Table 2. These unit rate recharge estimates provide an indication of the variability of groundwater recharge depending on surficial geologic deposits. There are a number of more recent water budget investigations that have been conducted within the study area that have involved the estimation of direct groundwater recharge. The results of these investigations are directly applicable to the Carruthers Creek watershed. The methods utilized include: • WABAS (Water Balance Analysis System; Clarifica Inc., 2002; Graham et al., 1997); • MODFLOW, a three-dimensional numerical groundwater flow model (McDonald and Harbaugh, 1988; Earthfx, 2006); and • GSFLOW (MODFLOW+PRMS) numerical modelling (Markstrom et al., 2008). A summary of the historical watershed recharge estimates using these various methods is included on Figure 17. These estimates are compared to streamflow groundwater discharge estimates using hydrograph separation and estimates of groundwater recharge and discharge from a MODFLOW model that included the Carruthers Creek watershed (Earthfx, 2006). Coupled PRMS-MODFLOW (GSFLOW) models were subsequently used to estimate groundwater recharge for TRCA and CLOCA watersheds (Earthfx, 2009a; TRCA, 2010). The spatial distribution of recharge estimated by the v02: July 25, 2017 Page 29 of 77 TRCA Carruthers Creek – Hydrogeology GSFLOW model for the TRCA jurisdiction (Earthfx, 2009a; TRCA, 2010) is shown on Figure 18. Estimated groundwater recharge over the South Slope till plain ranges from 60 to 90 mm/year. Recharge along the Lake Iroquois shoreline/beach (sand and gravel) is estimated at 180 mm/year. Recharge over the Lake Iroquois plain deposits is estimated to range from 36 to 90 mm/year. The average recharge rate for the Carruthers Creek watershed is estimated at 118 mm/year (Figure 17). Table 2: Summary of estimated recharge rates for different geologic deposits and physiographic regions applicable to the Carruthers Creek watershed. Numerical Groundwater Flow Models ORM Rouge Duffins ORM ORM Duffins Landfill Studies Gerber & MM Dillon Gerber Hunter1 Singer Smart Meriano Howard Mowatt Earthfx 1990 IWA, 1994e 1994 1996 1981 1994 1999 2000 2000 2006 3-D 2-D 3-D Oak Ridges Moraine hummocky 300-400 300-400 280-380 350 400 400 350 420 non-hummocky 320 hummocky till 335 325 250 360 South Slope Till Plain Halton Till 150-250 150-200 170-250 150-200 150 200 90 100-150 126 189 Newmarket Till 30 Glacial Lake Peel silty clay 50 35 50 100 90 sand 200 200 180 Glacial Lake Iroquois sand and gravel 150 200 200 200 180 clay and silt 50-100 0-40 25 100 90 diamict 50-100 25 100 90 Other recent deposits 160 Urban 0-40 50 60%2 Note: 1 Hunter et al. (1996) estimate for Oak Ridges Moraine > 275 m amsl. 2 Urban recharge factor where recharge is 60% of individual deposits value. v02: July 25, 2017 Page 30 of 77 TRCA Carruthers Creek – Hydrogeology Estimated Recharge & Discharge for Carruthers Creek study area 240 _._ -~- ~ D baseftow - streamflow hydrograph separation (02HC0061049; HY013; 02HC018) 220 ______,______, • WABAS recharge (Clarifica, 2002) D MODFLOW COR Model recharge (Earthfx, 2006) 200 -----< o MODFLOW COR Model groundwater discharge (Earthfx. 2006) • MODFLOW-PRMS Recharge (TRCA, 2010; Earthfx, 2009a) D MODFLOW-PRMS groundwater discharge (TRCA, 2010; Earthfx, 2009a) 180 160 • - I- - ~ 140 (II f "7 .§. 120 1-1------1------i.,, s 1, , __ ~ 100 .t: C: ::, 80 60 .-- 40 ,_ 1-1-- 1-1---1 ··· - 20 - 0 J Ouffins Creek French me n's Bey Carruthers Creek Lynde Creek Figure 17: Summary of available watershed recharge and discharge estimates for the study area. Carruthers Creek watershed baseflow estimate from gauging station HY013 (Carruthers Creek at Achilles; drainage area 26.9 km2; 2008 to 2016) is a minimum of 13 streamflow separation routines (Clarifica, 2002; Piggott et al., 2005; Institute of Hydrology, 1980; Sloto and Crouse, 1996; Rutledge, 1998; Nathan and McMahon, 1990; 1991; Chapman and Maxwell, 1996 and Echhardt, 2005) for the period 2008 to 2014. v02: July 25, 2017 Page 31 of 77 TRCA Carruthers Creek – Hydrogeology 0 0 ' 0 - 0 ' :;; 1Nlt!Jo'---jiill.. 'SI" 0 0 0 Ill E~ a "'C: Ill0 ·- N .s:: ti) t: (0 ~ 'SI" 650000 652500 655000 657500 660000 662500 Legend: Easting (m) - Lake Iroquois -135 masl -- Contour Line Start: 135 S te p : 1 S top: 136 - ORM Planning Boundary CTC SWP rechar e TRCA, 201 O; Earthfx, 2009a) 18 320 1 00 200 300 Date (y/m/d): 2017-07-24 Carru thers - recharge Figure 18: Estimated groundwater recharge for the Carruthers Creek watershed. Light blue = 36 mm/year; dark green = 60 mm/year; light green = 90 mm/year; orange = 180 mm/year. v02: July 25, 2017 Page 32 of 77 TRCA Carruthers Creek – Hydrogeology 3.3 Groundwater Flow Groundwater flow direction in the study area is generally north to south towards Lake Ontario with local deflections towards creeks and streams. The groundwater flow patterns for all three aquifers are shown on Figure 19 and Figure 20. Figure 21 illustrates areas where vertical groundwater flow through the Lower Newmarket till is downward (green) and upward (blue). Areas of downward vertical groundwater flow are where the deep aquifer system is replenished. The Carruthers Creek watershed can be considered to include two general hydrogeological settings including the north half with a thick package of Quaternary age sediments above bedrock (South Slope till plain physiographic region), and a southern half of the watershed over the Glacial Lake Iroquois physiographic region characterized by thin sediment thickness (<35 m) above shale bedrock. The transition between the two settings occurs along the break in topographic slope along the Lake Iroquois shoreline. Three aquifer systems are present within the northern part of the study area. Water table conditions exist within surficial tills while coarser aquifer sediments occur locally within deposits of the Oak Ridges Moraine/Mackinaw Interstadial as they pinch out south the Oak Ridges Moraine. Deep aquifers occur within deposits of the Thorncliffe and Scarborough Formations. In the southern part of the study area the deeper aquifers are closer to ground surface as erosive action within Glacial Lake Iroquois has eroded the Halton Till and locally eroded the Newmarket till and deposited glaciolacustrine sand, silt and clay on top. Water table conditions exist within these glaciolacustrine deposits or weathered Lower Newmarket till where present (Figure 10). v02: July 25, 2017 Page 33 of 77 TRCA Carruthers Creek – Hydrogeology I ."'!::: .s:: ~ z0 650000 655000 660000 665000 Easting (m ) Legend: x Water Table - masl (20160524) - ORM Planning Boundary - :-:::jC:::o:::nt:::ou:::r::;L;;:,n:::e:::S:::tairt:· :75::::::S:::la=p=· :::'Oj:S:::to;:p:::: 2::;9;:5::;a _ _ ___ 75 C 295 100 150 200 250 - Lake Iroquois -135 masl Date (y/m/d): 2017-07-12 -- Contour Line Start_ 135 Step: 1 S top~ 136 Carruthers - water table Figure 19: Shallow flow system water table/potentiometric surface. Groundwater flow directions are perpendicular to equipotential contours. v02: July 25, 2017 Page 34 of 77 TRCA Carruthers Creek – Hydrogeology I rn -~ .s:: ~ z0 650000 655000 Easting (m) Legend: x Deep Potentiometric Surface (20160524) - ORM Planning Boundary ssc=:::::=Contouri:: L::ine:::: Start::::::::~ 55 ::::::...S tep· .=::110 S top=:::: 295:. 1111!1!!!!1•••295 100 150 200 250 - Lake Iroquois -135 masl Date (y/m/d): 2017-07-12 -- Contour Lin e Start_ 135 Step: 1 S top: 136 Carruthers - TF potentiometric Figure 20: Deep flow system (Thorncliffe Aquifer Complex) potentiometric surface. v02: July 25, 2017 Page 35 of 77 TRCA Carruthers Creek – Hydrogeology I rn -~ .s:: t'. z0 650000 655000 660000 665000 Legend : Easting (m) • flowing wells x Shallow -Deep (20160524 - + ve down o., .. - ORM Planning Boundary ,o 20 30 60 x Shallow - Dee 20160524 - -v e u Date (y/m/d): 2017-07-12 ... -40 -30 -20 -10 - Lake Iroquois -135 masl Carruthers - vertical gw flow - comour une State 135 si.p: 1 Step: 136 Figure 21: Potential vertical groundwater flow directions. Shallow potentiometric surface/water table (Figure 19) minus deep potentiometric surface (Figure 20). v02: July 25, 2017 Page 36 of 77 TRCA Carruthers Creek – Hydrogeology Groundwater monitoring locations with data available to the author situated within the Carruthers Creek watershed currently do not exist. Historical groundwater level monitoring has been conducted at many locations within adjacent watersheds that can be applied to the Carruthers Creek watershed (Figure 22). These data are largely related to five groups of monitoring locations including: a) OMOECC monitoring locations initiated in the 1970s (Sibul et al., 1977); b) ORMGP monitoring locations (including adoption of some of the OMOECC locations above); c) Provincial Groundwater Monitoring Program (PGMN) monitoring conducted by a partnership between the OMOECC and Conservation Authorities (TRCA; CLOCA); d) Monitoring conducted by golf courses to fulfill requirements associated with receipt of a Permit to Take Water (PTTW); and e) Monitoring associated with Hwy 407 eastward extension construction. Groundwater monitoring data conducted by the TRCA (PGMN) and the ORMGP will be presented here as these are the only data available to the author. To summarize the aquifer systems and depth of aquifer screens, a west-east cross section through the South Slope till plain is shown on Figure 23. A west-east cross section through the Lake Iroquois plain is shown on Figure 24. One of the most extensively studied areas with a long history of groundwater level monitoring occurs within the adjacent Duffins Creek and Petticoat Creek watersheds (Gerber, 1999; Gerber Geosciences Inc., 2003; Ostry, 1979; Sibul et al., 1977). The PGMN monitoring network presently includes seven piezometers at three locations within the Duffins Creek watershed (Figure 22). The data available for these PGMN monitors is included on Figure 25 to Figure 29. Long term data from on-going monitoring are provided for a site near Claremont (Figure 30) and a site to the southeast of Whitevale near Taunton Road and Whites Road (Figure 31). Water table elevations observed in the Frenchman’s Bay area are included on Figure 32. These latter locations are discussed to illustrate the fluctuation of the water table within Glacial Lake Iroquois deposits that can be inferred to be similar within the Carruthers Creek watershed for similar deposits. v02: July 25, 2017 Page 37 of 77 TRCA Carruthers Creek – Hydrogeology 650000 655000 660000 665000 Legend: Easting (m) • ORMGP Monitoring Location • Hwy 407 monitoring wells - ORM Planning Boundary a PGMN - all • Golf Course well x Ground Surface-orm100mv5- masl (MNR v2) Date (y/m/d): 2017-03-30 135 275 150 175 200 2.25 250 275 Carruthers- gw monitoring locations Figure 22: Study area groundwater monitoring locations. v02: July 25, 2017 Page 38 of 77 TRCA Carruthers Creek – Hydrogeology Geology Legend West - R ecent deposits (Durham mode l; D ec 2007 ) East - Halton T ill - Oak Ridges Moraine/M IS (aquifer) - Lower Newmarket Till Tho rndiffe Fm. (aquifer) - Sunnybrook D rift Scarborough Fm. (aquifer) - T op of Bedrock (Durham m odel; Dec 2007) Duffins Creek Carruthers Creek Lynde Creek watershed watershed watershed Sidelin e 20 W estney Rd Sideline 4 Sideline 24 Brock Rd Sideline 12 Sideline 6 ake R idge Rd Country Ln i..,_ ~'-'----'---'--'---i.--'--_.__.____._ _.__;..i__..r....----J'---i.-....L...--'--'-----'---'----'---'-----'--'----'---'--' 0 2SOO sooo 7SOO 10000 Soction Oist ;:a.nco (m) Borehole Legend: Notes: Map Scale in metres ORMGP Monitoring Location - vertlcal 0xagg0raUon: 2ox Golf Course well - bor holes +/- 1 SOOm 0 1000 2000 3000 - Date: (tYVd/ y): 2017-07-13 REG-TRCA-Carru thers-W'E-x&-1 b Figure 23: West-East cross section through north part of Carruthers Creek watershed. Cross section location is shown on Figure 22. v02: July 25, 2017 Page 39 of 77 TRCA Carruthers Creek – Hydrogeology Geology Legend West - Recent deposits (Durham model; Dec 2007} East H a lton Till - Oak Ridges (or equivalent) York-Durham - Lower Newmarket T ill Lin e Rosebank Rd homcliffe Fm - Sunnybrook D iamict (or equivalent} Scarborough Fm (or equivalent ) --Top of Bedrock (Durham model; Dec 2007) Carruthers Duffins Creek Creek Lynde Creek watershed watershed watershed Brock Rd Church St West.ney Rd Salem Rd Hwy Count Audley Rd 4 1 2 Lane 0 5000 10000 15000 Sclction Ols t~neci (m) Borehole Legend : --ORMGP Monitoring Location Notes: Map Scale in metres --Hwy 407 monitoring wells - vertical exaggeration: 40X PGMN-all - boreholes +/- 2500m O 2000 4000 Golf Course well - Date (mldly): 2017-03-30 REG -TRCA-Carruthers-WE-xs-soulh Figure 24: West-East cross section through south part of Carruthers Creek watershed. Cross section location is shown on Figure 22. v02: July 25, 2017 Page 40 of 77 TRCA Carruthers Creek – Hydrogeology Monitoring Location Details - MOE Claremont Geologic MOE MOE Test Hole 4709 (from Sibul et al. , 1977) Interpretation :~~~ OW#/WWR# Elevation Depth Geologic Log Single Pt. Natural Gamma 9 (ft asl) (ft) Resistivity Log Log (125 ohms/in) (0.125 mr/in) 600 ---o F.. 11 ....• ..lllf 580 20 Lower NewmM S20 Sil!ytiltlltll4. 500 tmic:lil ..ddly Tllomcffle Fomlat10n 480 140 148 4-40 M1dlu01silr••d. i,,.,..tf,:MI Sunnybrook Drift ,20 188 CltY'\'dtll 600 200 SUrbOrough Siltysat1'11 3OW333/4605547 380 Fcxmation 1100$ lot.IS 23' 360 811c:lrlhlll J•~ (114 of bull 1 PGMN W012:GA039 Z PGMN W011: GA038 3 PGMN W010: GA037 Figure 25: Claremont Field Centre monitoring nest details. Site monitored by ORMGP and TRCA (PGMN). Claremont Field Centre Groundwater Monitoring 180 ,-:::::======:::::;----r-----7 OW329-0W331 Ground elevation = 180.26 mas/; OW332.0W333 Ground elevation= 181.69 mas/ 177 --OW329 {WT; screen bottom = 4.9mbgs) ~ .. • OW330 Lower Newmarket till (W012; GA039; 12.2mbgs) E :- 176 --OW330 {W012) • transduoor Note: ~ OW33I Middle aquifer {TF; 22.3mbgs) 1) 1970'sdata trom D. Sharma & M. Scaife (MOE), Sibul el ol., 1977;0stry, 1979;A.Piggoll, 1999. ~ OW332 Lower aquifer TF (WOll; GA038; 47.9mbgs) 2) 1994-2001 measured by U of Toronto (R. Gerber). --OW332 {WOll) • transduoor 3) > 2001measured byTRCA{PGMN) & ORMGP. -<>- OW333 LOwer aquifer (Scar/bedrock) (WOlO; GA037; 72.6mbgs) --OW333 {WOlO) . transducer 174 -1--======----1------1------l ··-· .... 172 171 01-Jan-1971 29-Dec-1980 27-Dec-1990 24-Dec-2000 22-Dec-2010 Figure 26: Groundwater levels at the Claremont Field Centre location. v02: July 25, 2017 Page 41 of 77 TRCA Carruthers Creek – Hydrogeology Monitoring Location Details - MOE Greenwood Geologic MOE MOE Test Hole 4710 (from Sibul et al., 1977) Interpretation :~~~ OW#/WWR# Elevation Depth Geologic Log 4 0 (ft asl) (ft) Glacial Lake Sand Sediments OW308/4605089 11869 CI::!117.85 Silt and clay Lower Newmarket 390 till Sand till Thorncliffe 310 Formation Sand and silt Sand till Sunnybrook 3SO Drift Silt clay OW337/4605548 330 9522 Stony sand till with Bedrock ,.,. Shale, some limestone (shale) 9306 1 PGMN W045-1; GA045 ~111 Figure 27: Greenwood Field Centre monitoring nest details. Site monitored by ORMGP and TRCA (PGMN). Greenwood Field Centre 125 124 123 122 121 120 NOie: 1. 1970'sdata from D. Shauna & M. Scaife (MOE). Sibul et al., 1911; Ostrv. 1979; Piggott, 1999. 2. I 994-1996 measured by U ofToronto (Gerber). ~ 119 3. > 2000measu,ed by TRCII (PGMN) and ORMGP. E ] 118 --OW308 (WT-Glaciolacustrinc; screen bottom t!J 4.5 mbgs) .!! B m -6-0W336 TF (PGMN W04S; screen bottom t!J 14.3 mbgs) J --OW336 (W04S) - transducer C 116 ~ -.-OW337 shale bedrock (saecn bottom t!J 28.lmbgs) 00 115 114 113 112 111 07-Jan-1971 04-Jan-1981 02-Jan-1991 30-Dec-2000 28-Dec-2010 Figure 28: Groundwater levels at the Greenwood Field Centre location. v02: July 25, 2017 Page 42 of 77 TRCA Carruthers Creek – Hydrogeology Site IWA EEll-1 groundwater monitoring 176 I I I-~ I I I • I I I I .. . ·\ -111- f\ il"\~ \1 ~ ....,. - ~-.. 174 l' -1' •v \.• '-J \ • - 1 ... II I I I I I 172 " H Ground Surface Elevation - 175.5 m a.m.s.l. -~ EE11-1 H 170 11t-1 ~, ABCOEFW --- ()oplh HT - / 168 (ml ":"!- - I# /" .. .. NI ; 10 I ...... J 166 . c j •• 20 • d 'ii;' 164 ...... ,·• .§."' . 30 I j j \ i;;d 162 ,- .,,.,,,::. ~"" . r II ..> - - ..... ""~ 40 ..!! ii -- - .t TF ~ .;a. .,_.._ ..• ~ Cl/ 160 50 ~-~-- ,- ~ ""'- :. 11 7 - -.. -· --- -~ - ,__ ~ 'tJ - 1A (WT in HT; PGMN W0 326-2) ' C 158 I- 60 ~~ Su e + 1B LOwer Newmarket till l•IY Northern Till) ,- \!) 70 156 ,- ~ -+-lW Thorncltte Fm. Waler levels Shale ,- April 20, 1994 --JC IThorncl~fe Fm.; PGM N W0326-3 ) 60 154 ,- --- 1 D Thorncliffe Fm. 152 1 F Bedrock. shale --lESunnybrook Drift ,-- ,- 150 ,-,- l 111\. - - ~ .... . - - .. ~ - ~ 148 -hr.-+ .-r - 0I-Jan-93 0l-Jan-95 31-0Cc-96 31-0Cc-98 30-0Cc-OO 30-0Cc-02 29-0Cc-04 29-0Cc-06 28-0Cc-08 28-0Cc-l0 27-0Cc-12 27-0Cc-1 4 Figure 29: Groundwater levels for Site EE11 (PGMN W326) Site monitored by ORMGP and TRCA (PGMN). Site 2/94 manual groundwater levels (Claremont) 242 240 ~ ::__~ . ,~ 0 • "- __j Ground surface 241.7 masll - 238 ~- ' 236 ! • -- 234 -- - ,. - _,.-... _, ------.... --- - 232 +---- ...... ;+I ...' --+--l---+--+--+--l---+--1---+-- ..+--t--l ~-l -+- 2/94"4 ORA( (Ml5a) +1-- 1• 2/94·3 ORAC (MISb) ft-- ] 230 E ; -1-- --·-&·-· 2/94-1 Lower Newmarketti ll (sa s.eam) !·tt- t--t•l--ti,H--t--+---t--t--t---t---t--t--l--t--1--+--I x 2/94-SA lower Ncwm~rket till :f 1- j 228 . ~~ ..!! • I --·• ·-· 2/94-58 Lowe r Newmarket ti ll 1 • '1 ,i= ~.. 226 I 2/94-i: Thorncliffc aquifer complc, er---- ~ "' ---- · -1-- --0 ·-· 2.75 Thornclifre aquifer com plex ;,~- C 224 e * d - t-----,t--t- - -1------·~ -- 1·75 Thornclirre aquifer complex ;l= 1---..,._--t1,1t-l --+=.~=-+---t--t--t--+--+--+---t--t--t--+-l ~ 4840 Thorncliffe aquirer complex ~ 1-- I!> 222 • H ,. • if::11.112 ' ~ ~ I ri 216 • +---+--+---+-Ill'•' i--; I ->--+--·+ :: 214 01-Jan-1994 31-0ec-1996 31-0ec-1999 30-0ec-2002 29-0ec-2005 28-Dec-2008 28-Dec-2011 27-Dec-2014 Figure 30: Groundwater levels for Site 294 near Claremont. Site monitored by ORMGP. v02: July 25, 2017 Page 43 of 77 TRCA Carruthers Creek – Hydrogeology Site 1/94 manual groundwater levels (Cherrywood) 16S -,----,,--...,..-.,...-,--....,.-...--,----,.--,--..---.--,--..----,-...,..-..----,-....,.--,--,----,.--,--.....--, Ground Surf,;,ce (165 mast) 163 +---<---+---+--t---+--+--t---+--+--+----+--+--+---;---+--+---<---+--+--t---+--+--+-----1 161 I JS9 11 1S7 ' 1/94 -;;;.. C S S g g3imm"91 (c.p3) 155 I- • IJ 20 40 1--t--l---+- -- 1/94-3, H•llon nt (wal , Iable) ~ Dapa>(,nbplj {--i ..s.; > ...... !?... ~~¢, 143 • .... " - - ~- - ' -i - "' -- ,. 01-Jan-1994 31-Dec-1996 31-Dec-1999 30- Dec-2002 29-Dec-2005 28-Dec-2008 28-Dec-2011 27-Dec-2014 Figure 31: Groundwater levels from Site 194 southeast of Whitevale near Cherrywood. Site monitored by ORMGP. Meriano piezometers- Frenchman's Bay area, Pickering 83.0 ---.- awl · Pint Ck N [2..3 Rl01Ji] 8l.O 81.0 80.0 -;;; "' .5, 79.0 .; > _," ~ 78.0 ,,"';i; C ~ 77.0 ~ 76.0 7S.0 74.0 -===-===-==---=-===-===-===-4'===-===-===-~ 01-J•n-08 31-0oc-08 31-0oc-09 31-0oc-lO 31-0oc-ll 30-0oc-ll 30-0oc-13 30-0oc:. 14 30-0oc-15 l 9-0oc-16 l9-0oc-l7 Figure 32: Water table elevations in Frenchman's Bay area (Meriano, 2007). Site monitored by ORMGP. v02: July 25, 2017 Page 44 of 77 TRCA Carruthers Creek – Hydrogeology W263 Heber Down (PGMN - CLOCA) (Water table in glaciolacustrine sand above till, screen 5.8-7.3 mbgs; just north of Lake Iroquois shoreline) 143 - Ground Elevation (142.62 masl) 142 - W263 Heber Down - logger l • W263 Heber Down - manual 1 141 1~~ "iii E"' oi 140 > _,QI ~ ~ "'~ "O 139 I: :::, ~ I.:) 138 137 136 1-Jan-2003 31-Dec-2004 31-Dec-2006 30-Dec-2008 30- Dec-2010 29-Dec-2012 29-Dec-2014 28-Dec-2016 Figure 33: CLOCA PGMN W263 Heber Down groundwater levels. Water table in glaciolacustrine deposits over till on the South Slope Till Plain physiographic region. The annual fluctuation of groundwater levels within a piezometer will depend on many factors including, but not limited to, the annual recharge rate, aquifer composition and storativity (e.g. gravel versus silty sand), aquifer type (i.e. unconfined versus confined), and position within flow system (recharge versus discharge area). A summary of groundwater level fluctuations for the monitoring sites presented previously is included in Table 3. Over the South Slope till plain, annual fluctuations of the water table within glaciolacustrine or glaciofluvial deposits generally ranges over a 2 m span, with the lowest water table occurring during late summer and early fall and highest water table elevations occurring during the spring. The water table within Halton Till deposits has a larger range of average annual fluctuation (3 m) because of the lower hydraulic conductivity and specific yield of the till. The natural annual fluctuation of groundwater levels within the deep aquifer system, the Thorncliffe and Scarborough aquifer complexes, is generally less than 1 m. Within the southern part of the Carruthers Creek watershed the water table within sediments over the Lake Iroquois plain fluctuates over a 0.5 to 1 m range. The water table over the Lake Iroquois plain is generally within 3 m of the ground surface (Figure 32). The lowest observed water levels for the period of record (decades) from natural seasonal fluctuations occurred during the fall/winter of 2016. These low groundwater levels have since recovered over the winter and spring of 2017. The largest impact to groundwater levels was a 5.5 m decline in the water table within Halton Till at site 194 (Figure 31). Groundwater level declines within the deep aquifer system were less than v02: July 25, 2017 Page 45 of 77 TRCA Carruthers Creek – Hydrogeology 2 m compared to an average annual range of 1 m, illustrating the greater tolerance to drought for groundwater supplies obtained from the deep aquifer system (Thorncliffe and Scarborough Aquifer Complexes). Table 3: Groundwater level fluctuation summary. North South Location Claremont3 Claremont4 Taunton Rd. Cherrywood Greenwood5 Heber Down6 Frenchman's Field Centre 2/94 EE11-1 194 Cons. Area W263 Bay Hydrograph Figure 25 Figure 29 Figure 28 Figure 30 Figure 27 Figure 32 Figure 31 Physiographic Region South Slope South Slope South Slope South Slope Iroquois Plain Iroquois Plain Iroquois Plain Hydrostratigraphic unit Glaciolacustrine (WT) 2.0/3.5/1.0 0.75/1.5/0.5 1.3/3.0/1.0 0.5/1.4/0.3 Halton Till (WT) 1.5/2.5/1.0 3.0/5.5/1.0 Mackinaw Interstadial 3.0/5.5/1.0 Oak Ridges aquifer 1.5/3.0/1.0 I ...... 1 Lower Newmarket Till 1.0/1.0/0.5 1.0/1.5/0.5 Thorncliffe Fm 0.3/1.5/0.5 2.0/5.0/1.0 0.5/2.0/0.2 0.8/1.0/0.2 0.75/1.5/0.5 0.8/1.0/0.5 Sunnybrook Drift Scarborough Fm 0.8/1.0/0.5 Bedrock (shale) 0.5/0.5/0.2 0.2/0.5/0.1 Note: 1) WT = water table; bold-italics = aquifer units. 2) 1.3/3.0/1.0 = approximate average/maximum/minimum annual groundwater level change for period of record (m). 3 water table in sand and gravel deposits within East Duffins Creek valley. 4 confined Oak Ridges Moraine aquifer complex. 4 Thorncliffe aquifer groundwater levels may be affected anthropogenically. 5 water table in sand and gravel deposits within East Duffins Creek valley, south of Lake Iroquois shoreline. 6 water table in sand and gravel deposits along Lake Iroquois shoreline. 3.3.1 Hydraulic Properties The amount and rate of groundwater flow through porous media is determined by the hydraulic properties of the unit, particularly hydraulic conductivity (K), the hydraulic gradient (i) and porosity (n). The response of a flow system to various stresses is largely determined by the previous mentioned parameters along with storage. Hydraulic conductivity is a key hydraulic parameter and can be estimated by numerous field and laboratory methods including slug tests and pumping tests. A summary of available K estimates applicable to the study area is included in Table 4 and Figure 34. This summary of hydraulic conductivity estimates is provided to inform future groundwater investigations in the study area, including the proposed numerical groundwater flow modelling as Phase 2 of this Carruthers Watershed Watershed Plan. Hydrogeologic investigations conducted by MM Dillon Limited (MM Dillon Limited, 1990; Interim Waste Authority, 1994a-e) and continued by Gerber (1999; Gerber and Howard, 1996; 2000; Gerber et al., 2001) suggest that bulk hydraulic conductivity (K) of the Lower Newmarket Till is controlled by structures or pathways (Gerber et al., 2001). Horizontal pathways include sand and gravel interbeds and boulder pavements marking erosional v02: July 25, 2017 Page 46 of 77 TRCA Carruthers Creek – Hydrogeology surfaces identified in the Newmarket Till in outcrop and shallow seismic reflection profiles (Boyce et al., 1995). Vertical pathways include fractures, sand dykes and steeply-dipping shear surfaces. Isotopic data (2H, 18O and 3H) and regional water balance/groundwater flow modeling (Gerber, 1999) suggest vertical bulk K values on the order of 5 x 10-9 to 10-10 ms-1. Matrix K estimates from triaxial permeability and slug testing, in contrast, yield much lower estimates ranging from 10-11 to 10-10 ms-1. Vertical leakage through the Newmarket Till to the underlying Thorncliffe Formation is estimated at 30-40 mm/year on a regional basis. These same types of secondary permeability structures are also present within the surficial Halton Till. A summary of all estimates for till deposits within the study area and estimated bulk vertical hydraulic conductivities for the Halton Till and the Lower Newmarket till are included on Figure 35 and Figure 36. v02: July 25, 2017 Page 47 of 77 TRCA Carruthers Creek – Hydrogeology Table 4: Summary of hydraulic conductivity estimates. Minimum Maximum Average no. Geometric Mean (m/s) (m/s) (m/s) (m/s) Upper Deposits -8 -6 -6 -7 Glaciolacustrine - silt slug Kh 5x10 4x10 2x10 5 4x10 -11 -4 -6 -8 Halton Till slug Kh 3x10 7x10 6x10 127 2x10 -6 pump Kh 6x10 1 -8 -7 pump Kv 1x10 1x10 1 -6 -3 -5 Oak Ridges Moraine spec-cap Kh 2x10 7x10 1287 5x10 -10 -4 -5 -6 ORM & MIS slug Kh 8x10 5x10 3x10 104 4x10 Lower Newmarket (aka Northern) till -11 -10 -11 -11 lab Kv 1x10 7x10 5x10 40 3x10 -12 -6 -7 -10 slug Kh 3x10 3x10 3x10 39 8x10 -6 pump Kh 6x10 1 -11 -7 pump Kv 3x10 3x10 4 Thorncliffe Aquifer complex -9 -4 -5 -6 slug Kh 4x10 6x10 5x10 109 4x10 -7 -5 -5 -6 pump Kh 1x10 9x10 3x10 4 5x10 -6 -3 -5 spec-cap Kh 1x10 2x10 286 4x10 Sunnybrook Drift 1 -10 -5 -6 -8 slug Kh 9x10 3x10 4x10 9 2x10 Scarborough Aquifer Complex -8 -4 -5 -6 slug Kh 2x10 2x10 5x10 5 2x10 -7 -4 -5 spec-cap Kh 6x10 7x10 311 2x10 Bedrock -8 -4 -5 -6 limestone slug Kh 2x10 2x10 2x10 31 3x10 -10 -5 -6 -7 shale slug Kh 1x10 1x10 1x10 28 2x10 Note: ORM = Oak Ridges Moraine; MIS = Mackinaw Interstadial Kh = horizontal hydraulic conductivity Kv = vertical hydraulic conductivity Data from MM Dillon Limited, 1990; IWA, 1993a-d; IWA, 1994a-j; Gerber, 1999; Golder, 2006; CH2M Hill, 2009; Coffey, 2011; spec-cap = Specific Capacity estimates from water well records. Specific capacity estimated according to Bradbury and Rothschild (1985) from Boyce, 1997. 1 includes piezometers in sand layers in aquitard unit. v02: July 25, 2017 Page 48 of 77 TRCA Carruthers Creek – Hydrogeology Hydraulic Conductivity Estimate Comparison by Stratigraphic Unit ' G/acio/acuslrine I •• • • Halton ti/I/Upper Newmarket till (aquitard) - .,. --- ~ !l_K_, n~ ...... 0 (ll ,, • t ·-··-·· -··DCD> ~-----~- 0CJlllOcmD qo 00 CD· r;K,, :-;:;:;; ORACIMJS/INS aquifer compt;;;.;j (K~ n•104) ,--L• • -::i II I ·7~ • @ D DD D@ DD • fMIS K,,~ ) +-·-D D - antj DD Lower Newmarket till (aquitard) a (K"' ; n= 28 ) (ll • 0• 00• 0O(l)(X)Cl'.)()• •• 0 O(l)Q. l 0 0. 0 CXDO o cmo•• 0 00 00 0 (K,; n•58) b-61& b ltK · n•401 •-- - Thomcliffe aquifer comple- x I i< ; n•1091. •• I I fK,,; n=42) ..D - D ·---o oam aqi 000000 ~ D ID- -D D-- Sunnybrook Drift (aquitardli I (K, ; n•11) • • • •• • 00 I • I Oa qu~ ard - slug test (Kh) Scarborough aquifer compie ~ I D D a • a a 6 aqu~ ard - lab (tri axial; Kv) I I I I I • • quit"' - slug test (l Figure 34: Summary of hydraulic conductivity estimates for various stratigraphic units. Data sources listed on Table 4. v02: July 25, 2017 Page 49 of 77 TRCA Carruthers Creek – Hydrogeology Surficial Till (Upper Newmarket; Halton till ; or equivalent) 338 km' 3,579 km' 15,133 km' 1.E-04 P1 1.E-05 - - -- : f! o~s Gerbe 1.E-06 1999 1 EE11 ll - Li et al. , 1.E-07 I 2008 ~ I I I IWA I lcOF~I i ~ EE11 , P1 - 1.E-08 -• 1 Numerical Flow Modeling (K.) 1 ~ IX$IC t ,s oxx + - - + ~ 1.E-09 o slug test - West (Peel Reg ion ; Kh ; n=80) ~ I x slug test (York; Kh; n=25) 1.E-1 0 8 * x slug test (Durham; Kh ; n=54) X + + slug test (YPDT db; 09-May-2014; Kh ; n=127) 1.E-11 "' pump test - Site EE 11 (Kv) 1.E-12 - 3D numerical models : .,. Estimated regional bu lk Kv 1.E-13 - - 0 2 3 4 5 6 7 8 9 10 Increasing relative volume of aqultard tested (not to scale) Figure 35: Summary of hydraulic conductivity estimates for surficial till deposits. Lower Newmarket (aka Northern) till 100km' 338 km' 3,579 km' 15,133 km' 1.E-04 I Pumping Test (Kv) I 1.E-05 X o ! .+. 2D X Y PDT-CAMC 1.E-06 +------1Generic vi' (max-Kv) Tunnel Channel --E Gerber, 1999 silt -t--~ ~~~---,,;---A-----, -t------1 g 1.E-07 Estimate X ~ ofX ... : ~ lcoRI Earthfx, 2006 '> 1.E-08 +-~~~----0----&,-----1---- •- ->=c---1 1----..-----r---1Re 'I- ~ ::, X "C ... C: 1.E-09 0 + (.) ~ X ... -~ X 1.E-10 X ::, 16th Avenue C'il lower beneath ORM ...... Dewatering (Kv) "C d >- xx I 1.E- 11 X xx Triaxial o slug test (Peel; Kh ; n=6) 1.E-12 Perm "Slug test (York ; Kh ; n=8) (n=42; Kvl x slug test (Durtiam ; Kh ; n=37) INumerical Flow Modeling (Kv) I 1.E-13 0 2 3 4 5 6 7 8 9 10 Increasing relative volume of aquitard tested (not to scale) Figure 36: Summary of hydraulic conductivity estimates for the Lower Newmarket till. v02: July 25, 2017 Page 50 of 77 TRCA Carruthers Creek – Hydrogeology 3.4 Groundwater Discharge If a flow system, in this case a watershed, is closed and long term storage changes are assumed equal to zero, then the total precipitation minus total streamflow can be considered an approximation of the amount of evapotranspiration that is occurring on a regional basis. Similarly, in a closed system without long-term changes in storage the amount of groundwater recharge can be assumed to approximate the amount of groundwater discharge. An assessment of streamflow is then an important component of any hydrogeologic investigation, particularly the water budget component. This section provides an analysis of the available streamflow data for the study area. This includes long-term gauged data and also low flow streamflow surveys. Also provided are estimates of the groundwater discharge component of the total streamflow hydrograph and the results from low flow streamflow surveys which can be considered a surrogate for aquifer mapping. The streamflow measurement and gauging stations present within the study area are shown on Figure 37. Within the study area, groundwater discharge is generally focused along two distinct hydraulic settings. The major groundwater discharge zone within the study area occurs along the south slope of the ORM where discharge is solely from the Oak Ridges Moraine Aquifer Complex. The second major groundwater discharge zone occurs along and south of the Lake Iroquois shoreline where the shallow water table and two deep aquifer complexes discharge to rivers and their associated valleys (springs). As mentioned previously, if a watershed is acting as a closed system where no long term changes in storage occur and groundwater flow does not flow across watershed boundaries, then the amount of groundwater discharge to the stream can be considered to be equal to groundwater recharge averaged over the catchment area. In a simplistic and practical sense, the streamflow hydrograph based on daily average flows can be separated into two components - runoff and groundwater discharge. Interflow (unsaturated zone flow) is not explicitly estimated in this treatment but assumed to be included in either recharge or runoff. Groundwater discharge estimates from streamflow hydrograph separation basically involve removing the runoff or storm/melt events which form peaks on the hydrograph over relatively short durations (hours to days). The groundwater component is considered to be the more consistent contributor to streamflow with annual fluctuations seen as gradual changes in the hydrograph. The three-dimensional numerical groundwater flow models use groundwater discharge estimates from hydrograph separation as one of the flux calibration targets. One method of streamflow separation from daily average streamflow measurements assumes the groundwater discharge component to be approximately equal to a 5 day running average of the 7 day running minimum daily average flow. This method yields estimates similar to the WABAS method (Clarifica, 2002). Any hydrograph separation method yields what should be considered an approximate estimate for both runoff and groundwater discharge, with each of these components considered as a range of values. The minimum groundwater discharge estimate would correspond to simply removing the peaks on a streamflow hydrograph. The 5 day running average of the 7day running minimum yields groundwater discharge estimates higher than this threshold, based on the belief that part of the peak of a storm or runoff event is still groundwater discharge contributed by a v02: July 25, 2017 Page 51 of 77 TRCA Carruthers Creek – Hydrogeology rising water table following a storm event. The key component then for any hydrograph separation is to compare results to those from other lines of evidence or methodologies. Low flow streamflow surveys measure the discharge at various points along a river reach during a period without influence from storm events. All or most of the flow in the stream during this period of time is assumed to represent groundwater discharge. The objective of these surveys is to delineate those reaches receiving groundwater discharge. This information is used during groundwater flow modeling as a flux calibration target relating to the spatial distribution of groundwater discharge. The data from these surveys is not presently being used as a total groundwater discharge flux calibration target because groundwater discharge varies throughout the year reflecting the saturation state of the watershed (i.e. high in spring, low in late summer). Protocols have been developed by the Geological Survey of Canada (Hinton, 1996), the Ministry of Natural Resources and various Conservation Authorities, and these protocols are followed during all low flow surveys presently being conducted by Conservation Authorities. Within the study area, low flow streamflow surveys have been conducted by the TRCA, CLOCA, the Geological Survey of Canada (GSC) and Conestoga Rovers and Associates (CRA, 2003). The measurement locations are shown on Figure 37. These surveys have all been conducted during different years. The TRCA has conducted surveys within Carruthers at the multiple stream locations in 2000, 2005 and 2013. Other years between 2004 and 2016 had flows measured at only 3 or 4 indicator stations to maintain a baseline for yearly comparison. The headwaters of Duffins Creek and Lynde Creek emanate from the ORM which occurs to the north of the Carruthers Creek watershed. Carruthers Creek headwaters occur over the South Slope till plain situated south of the ORM within rural and largely agricultural areas. The relationship of the Carruthers Creek headwaters to Duffins Creek to the northwest and Lynde Creek to the northeast is illustrated on Figure 38. The elevation of Duffins Creek (and Lynde Creek to the east) is situated such that these reaches are expected to capture much of the discharge to streams emanating from the ORM, thereby limiting the amount of lateral groundwater flow moving southward into the Carruthers Creek watershed. The lower reaches of each watershed near Lake Ontario are dominated by lacustrine deposits laid down within Glacial Lake Iroquois, or ancestral Lake Ontario. Figure 39 illustrates observed streamflow for TRCA stream gauges situated within the Carruthers Creek watershed. Figure 40 compares annual average streamflow for the TRCA Carruthers Creek HY013 Carruthers at Achilles gauge and streamflow measured in adjacent watersheds. Average annual precipitation measured at three local climate stations (Figure 5) ranges from 815 to 852 mm/year. The average total streamflow within the Carruthers Creek watershed is approximately 435 mm/year (period 2008 to 2016) when averaged over the drainage area (26.9 km2). The estimated minimum baseflow (considered here to be equivalent to groundwater discharge) component of the streamflow hydrograph is approximately 105 mm/year, or 24% of total streamflow averaged over the drainage area. The spatial distribution of groundwater discharge for the Duffins and Carruthers watersheds inferred from low flow streamflow surveys conducted by the TRCA is shown on Figure 41. Relatively significant groundwater discharge zones within the watershed occur along the east branch of the headwater area, perhaps reflecting discharge from v02: July 25, 2017 Page 52 of 77 TRCA Carruthers Creek – Hydrogeology the Oak Ridges Moraine aquifer as it pinches out in the northern part of the watershed. There is relatively little discharge occurring across other parts of the till plain covering the northern half of the watershed. The other area of significant groundwater discharge occurs south of the Lake Iroquois shoreline where the deeper aquifers occur closer to ground surface and intersect with stream reaches. v02: July 25, 2017 Page 53 of 77 TRCA Carruthers Creek – Hydrogeology I rn C: :i: t: z0 655000 660000 665000 Legend: Easting (m) o TRCA streamflow gauges • HYDAT (Env Canada) - ORM Planning Boundary • spot flow survey X Ground Surface-orm100mv5-masl (MNR v2 135 275 Date (y/m/d): 2017-04-03 ,so 17S 200 225 250 2?5 Carruthers - stream monitoring locs Figure 37: Streamflow monitoring stations within the study area. v02: July 25, 2017 Page 54 of 77 TRCA Carruthers Creek – Hydrogeology North Geologic Interpretation Legend South Crest of ORM - Recent deposits (Durham model; Dec 2007) - Halton Till Duffins Creek Carruthers - Oak Ridges Moraine/MIS (aquifer) watershed Creek - Lower Newmarket T ill watershed Thornclitfe Fm. (aquifer) - S unnybrook Drift Scarborough Fm. (aquifer) Top of Bedrock (Durham model; Dec 2007) I ~ j w Carruthers Ck @ Lake Ontario 10000 15000 20000 25000 30000 So,c.ti,on Di51.> nc.o { m) Notes: - vertical exaggeration: 40X Map S cale in metres - boreholes +/- soom - Date (y/m/d): 2017-07-21 0 2000 4000 6000 reg-duffins-ns-xs-+8000m Figure 38: North-south cross section along Salem Road. v02: July 25, 2017 Page 55 of 77 TRCA Carruthers Creek – Hydrogeology Carruthers Creek Watershed 100 - HY013 Carr uthers Creek at Ach il les (26.9 km2) - HY090 Carrut hers Creek at Taunton (17.8 km2) - HY089 West Ca rruthers above Taunton - East Carruthers above Taunton (HY090 - HY089) 10 0.01 0.001 01-Jan-2007 31-Dec-2008 31-Dec-2010 30-Dec-2012 30-Dec-2014 29- Dec-2016 Figure 39: Daily average streamflow for TRCA Carruthers gauges. Duffins Creek/Carruthers Creek/Lynde Creek Watersheds 5.0 -+-02H 006 Ouffins Cree k at Pickering (249 km 2) -+-02H 04 Ouffins Cree k at Aja, (2S l km2) -+-021K018 Lynde Cree k near Whilby (106 krn2) 4.5 - 02HC019 Duffins Creek above Pickering (93.5 km2) - 02HC055 Lynde Creek tributary near Kinsale (37.7 km2) --HY013 Carruthers Creek at Achilles (26.9 krn2) 4.0 3.5 ..,§ E i 3.0 u:0 E "'., 2.5 t; 76 ::, 2.0 C C 0.5 0.0 1945 1955 1965 1975 1985 1995 2005 2015 Figure 40: Average annual streamflow for study area gauges. v02: July 25, 2017 Page 56 of 77 TRCA Carruthers Creek – Hydrogeology f('f-i:.O" ,,s, ~,-of. ~~ "°"' \ ~~ t, \ ~.,.'° "'\ t, \~,.of. \t, \ "' ~,.o ,c"'°"' ~~- 1.r»~,s, \\ \t, t, \t, .. ~,.o ¢> \ ~ \i rJll' ;p ¢> \ ~ ,.0.,. \ \ t, I.,. t, \ ~ .,. _,.'ltlst"' f\"°'~ \t, \ \ ~~ "''f\!lst t, 'I / ~ Conser~ation N Carruthers Creek: Flow Rate (Lis/km) for The Living City• A Baseflow Normalized to - -0.517283 0.49 - 2.1 1 Date: October26,2016 Orthophoto: Sprlnc 2015, First Base Solutions Inc. Stream Length 0 0.82 - 2.85 Cre.111.d by: T.R .C.A. lnformatlon Servkes/lnformatlon Technolo1I•$ Disclaimer: The Datil used to crHte this map was complied from I variety s.ourc.s & dates. TheT.R.C.A . takes no responsi bi lity for erron or 0. 14 - 0.88 - 2.90 omiuions in the data and r-alns the rl1ht to make ch;in1e5 & corrections at anytime without notice. For further Information about the data on this map, pleue cont.ct the T,R.C,A, 0 0·:J5 0.21 - 1. 12 - 3. 17 GIS Department, (416) 661-6600. •--= --'===---•Kilometen. Figure 41: Carruthers Creek watershed low flow streamflow survey summary (figure from TRCA, July 2017). v02: July 25, 2017 Page 57 of 77 TRCA Carruthers Creek – Hydrogeology 3.5 Groundwater Quality While long-term groundwater level and chemistry trends for specific sites within the Carruthers Creek watershed are unavailable, there have been a number of studies conducted which provide an indication of background groundwater quality within adjacent watersheds including the Duffins Creek and Rouge River watersheds to the west, and from the Lynde Creek watershed to the east (CLOCA). These studies include: • Sibul et al. (1977) for the Duffins Creek and Rouge River watersheds; • Howard and Beck (1986) for the Duffins Creek and Rouge River watersheds; • landfill investigations (M.M. Dillon Limited, 1990; IWA, 1994a-e); • surface water sampling by the TRCA and the GSC (1995/1996), and • historical MOE surface water quality sampling data from the Provincial Water Quality Monitoring Network (PWQMN); • Provincial Groundwater Monitoring Network operated by the MOECC and various conservation authority partners; and • Watershed characterization reporting as part of the Source Water Protection program for the TRCA (2007) and CLOCA (2007) jurisdictions. The surface water quality data by the TRCA, GSC and the MOE are being discussed under separate cover as part of this Carruthers Creek Watershed Plan update and are not discussed here. Ultimately, the groundwater quality information presented in this section should be reconciled with the surface water quality information. The following discussion relates to the groundwater studies conducted within the surrounding Duffins Creek, Rouge River and Lynde Creek watersheds. The first extensive study of groundwater quality in the study area was conducted in the Duffins basin by the MOE in 1970 and 1974, and involved the analysis of 44 groundwater samples from the Duffins Creek and Rouge River drainage basins (Sibul et al., 1977). Groundwater within the shale bedrock was found to have low well yields and poor water quality, particularly for sodium and sulphate, consistent with subsequent analyses conducted for landfill investigations (M.M. Dillon Limited, 1990; IWA, 1994e) and unpublished data from sampling by the University of Toronto during the summer of 2000 (Gerber, unpublished data). The shale bedrock is not considered to be a useful geologic unit for a suitable water supply. Within the Duffins Creek and Rouge River watersheds to the west, groundwater quality does not appear to vary significantly within any of the three aquifer complexes within the unconsolidated deposits above bedrock (Sibul et al., 1977; Howard and Beck, 1986), and appears to be of generally good quality for domestic use. Local occurrences of natural high hardness and iron values are reported. Also, locally elevated levels above drinking water criteria for nitrate (> 10 mg/L) and chloride (> 250 mg/L) are believed to represent contamination from anthropogenic activities (Sibul et al., 1977). A subsequent analysis of 260 groundwater samples in the Duffins and Rouge basin between 1982 and 1984 (Howard and Beck, 1986) also revealed the presence of elevated chloride and nitrate values attributed to road salt and nitrate fertilizer use, respectively. Groundwater quality concerns at the present time appear to be isolated occurrences of 1) nitrates and bacteria associated with septic system effluent entering private wells and 2) high chloride values above drinking water criteria (250 mg/L) occurring in private wells situated next to v02: July 25, 2017 Page 58 of 77 TRCA Carruthers Creek – Hydrogeology salted roadways. A groundwater sampling and analysis study by CLOCA (2007) also identified elevated chloride concentrations (> 250 mg/L) within the Lynde Creek watershed situated east of the Carruthers Creek watershed. Investigations conducted within the Duffins watershed near Whitevale and Claremont provide insight into the natural chemical evolution of groundwater as it flows through the groundwater flow system (Interim Waste Authority, 1994a-e; MM Dillon Limited, 1990). The major ion chemistry from these investigations is plotted on Durov diagrams in Figure 42. Durov diagrams plot relative percentages of major ions and are useful for classifying waters and delineating evolutionary trends (Zaporozec, 1972). Shallow groundwater within the upper aquifer and the water table within Halton Till and Glacial Lake Iroquois deposits is generally dominated by calcium and bicarbonate ions. At greater depth within the Lower Newmarket till which separates the upper and deeper aquifer systems (Thorncliffe aquifer), groundwater is dominated by sodium and sulphate ions with lower concentrations of calcium, magnesium and bicarbonate. It is not known whether the source of the sulphate is indigenous to the till or introduced by anthropogenic activities. Natural sources of sulphate for the till waters could include dissolution of gypsum, or oxidation of pyrite which has been observed in granitic boulders within the till. Anthropogenic sources of sulphate could include industrial air emissions or fertilizer application. The increase in sodium within the till groundwater is likely due to ion exchange reactions with clay minerals which remove calcium and magnesium from solution. Groundwater within the Thorncliffe aquifer situated beneath the Lower Newmarket till is characterised by low sulphate concentrations, the dominance of sodium and bicarbonate, and the occasional presence of H2S gas from sulphate reduction reactions. Slight increase in calcium and magnesium from renewed dissolution of carbonate minerals is also evident. Consistent with historical investigations discussed previously, elevated chloride concentrations above background are found within shallow monitoring wells situated near salted roads, and also associated with some deep monitoring locations within bedrock (Figure 42). Uncontaminated groundwater generally has Total Dissolved Solids (TDS) concentrations less than 1000 mg/L, and often less than 500 mg/L. The presence of elevated Chloride concentrations can increase TDS to well above 2000 mg/L. Chloride concentration data from PGMN groundwater monitoring wells situated within the study area are shown on Figure 43. Shallow locations (W326-2; W263) have historical elevated chloride concentrations above the Ontario Drinking Water Objective (aesthetic) of 250 mg/L; however, concentrations at W263 (Heber Down – CLOCA PGMN) are on a declining trend. Two deep monitoring wells within the Thorncliffe Formation (W326-3; W011) have low chloride concentrations (< 10 mg/L) but are showing an increasing concentration trend. W326-3 may be experiencing rising levels due to migration of road salt contamination to depth while W011 may be receiving upward groundwater flow from shale bedrock where concentrations within the Scarborough and Thorncliffe aquifers are approaching similar values. Further work is necessary to determine the causes of these rising chloride trends. v02: July 25, 2017 Page 59 of 77 TRCA Carruthers Creek – Hydrogeology Duffins Creek watershed (Sites P1, EE11; UofT -1/94 & 2/94) + Glacial Lake Iroquois (n=17) x Halton Till and Mackinaw lnterstadial (n=89) o Lower Newmarket (aka Northern) till (n=46) • basal part of Lower Newmarket till (n=24) • Thomcliffe Fm (n=61) • Contact zone/Bedrock (n=19) TDS(mg/L) 500 1000 I xix 0 [ X X .~ X 0 X + + t -r · +: TDS = 2550 m /L x..,._--1------' ' ' ' • 4------l----'----'-----+-----+-----t--+-.TDS =. 4870 _mg/L Figure 42: Durov plot of major ion chemistry from sites within Duffins Creek watershed. Data from MM Dillon Limited, 1990, IWA, 1994a, 1994e, and Gerber, 1999. v02: July 25, 2017 Page 60 of 77 TRCA Carruthers Creek – Hydrogeology Carruthers Creek watershed 10,000.0 1,000.0 ... ················• ·- -- ...... ---- ..• :;; .t:::::::::::::: ...... -..E 100.0 · · • ·· W326-3 Taunton Rd (TRCA-PGMN; EE11-1C; Thorncliffe Fm.) C .Q -+-W263 Heber Down (CLOCA-PGMN; urficial till - water table) ~ _,.,._ W012 Claremont CA (TRCA-PGMN; OW330; Lower Newmarket till) --W0ll Claremont CA (TRCA-PGMN; OW332; Thorncliffe Fm.) ~ C -o-WOl0 Clarerroont CA (TRCA-PG MN; OW333; sca,borough Fm.) 0 .,u • W045 Gre nwooo CA (TRCA-PGMN; OW336; Thornclilfe Fm.) 3! 10.0 ...... • Ontario Drinking water Objective (aesthetic) 0 J: u 1.0 ·······---.. 0.1 01-Jan-1994 31-Dec-1998 30-Dec-2003 28-Dec-2008 27-Dec-2013 Figure 43: Groundwater chloride concentrations from PGMN (TRCA and CLOCA) monitoring wells adjacent to the Carruthers Creek watershed. Groundwater monitoring locations are shown on Figure 22. W263 is from the Lynde Creek watershed and is monitored by CLOCA (PGMN). All other monitors are from the Duffins Creek watershed and are monitored by the TRCA (PGMN). 3.6 Numerical Groundwater Flow Modelling Numerous numerical groundwater flow models have been constructed that include the Carruthers Creek watershed, although none of these modelling efforts have focused on the Carruthers Creek watershed. These models have all been collected by and are currently managed by the ORMGP. These models have been constructed for a myriad of uses largely aimed at providing guidance to various groundwater management initiatives. Other more specific uses include: • Water budget investigations; • Source Water Protection Investigations; • Watershed management plans; • Estimate land use change impacts; • Wellhead protection and water supply investigations; and • Fisheries and resource management. v02: July 25, 2017 Page 61 of 77 TRCA Carruthers Creek – Hydrogeology Initial modelling efforts focused on the construction of a regional model encompassing the entire ORM (240 m grid; Earthfx Inc., 2006) and utilized the ORM geology recently constructed by the Geological Survey of Canada. Subsequent efforts have focused on the construction of a finer grid model (100 m) known as the COR (Central Oak Ridges) Model (Earthfx Inc., 2006) which encompasses much of the TRCA watersheds and extends north to Lake Simcoe. Subsequent modelling efforts have produced refined versions of the COR model. The existing numerical flow models are summarized on Figure 44 and Table 5. The TRCA currently uses recharge estimates from Earthfx (2014b) for all watersheds except Etobicoke Creek where estimates from TRCA (2010) are used. Phase 2 of the groundwater component of this Carruthers Creek Watershed Plan update will see various land use scenarios analysed using an existing numerical groundwater flow model. This numerical flow modelling will focus on water budget aspects, and refinements will include checking the current calibration with updated information related to streamflow and groundwater levels. < ili,iiM ;z )( C ClOCA 'ESGRA fUSI model] MODEL NAME: ClOCA ESGRA !fist model! - Figure 44: Existing numerical flow model locations. v02: July 25, 2017 Page 62 of 77 TRCA Carruthers Creek – Hydrogeology Table 5: Summary of existing numerical groundwater flow models for study area. Bold- italics = model encompasses the Carruthers Creek watershed. Model Name Year Modelling Purpose Model Reference Software Code Area (km2) Regional 2004 MODFLOW Regional Flow 14,524 Earthfx, 2006 COR 2006 MODFLOW Regional Flow 3,574 Earthfx, 2006 COR West 2007 MODFLOW WHPA 4,720 Earthfx, 2007 Durham 2009 MODFLOW Regional Flow 3,373 Earthfx, 2009b. TRCA_SWP_Tier 1 & 2 2010 PRMS SWP Tier 1 & 2 2,565 TRCA, 2010 York SWP Tier 3 (GW Vistas) 2013 MODFLOW (GW Vistas) WHPA 3,745 Golder, 2013a, 2013b, 2015 CLOCA_SWP_Tier1 (East Model) 2009 MODFLOW-PRMS SWP Tier 3 wb 1,509 Earthfx, 2009a. CLOCA_ORMCP (East Model) 2011 MODFLOW-PRMS ORMCP 1,509 Earthfx, 2011 CLOCA ESGRA (East Model) 2014 MODFLOW-PRMS ESGRA 1,509 Earthfx, 2014a. York SWP Tier 3 2014 GSFLOW SWP Tier 3 wb 3,745 Earthfx, 2014b. v02: July 25, 2017 Page 63 of 77 TRCA Carruthers Creek – Hydrogeology 4.0 SUMMARY AND CONCLUSIONS The groundwater conditions within the Carruthers Creek watershed have been documented utilizing high-quality data that exists within adjacent watersheds, here considered to the directly applicable to the Carruthers Creek watershed. These data have been augmented with relatively lower quality data (e.g. MOECC water well records) and streamflow gauging records (since 2007) that exist within the watershed. Three aquifer systems are present within the watershed, one shallow and two deep including: • The Oak Ridges Moraine/Mackinaw Interstadial aquifer complex (shallow); • The Thorncliffe aquifer complex (deep); and • The Scarborough aquifer complex (deep). The shallow Oak Ridges Moraine/Mackinaw Interstadial aquifer complex occurs beneath the surficial till deposits within the northern part of the watershed and locally to the Lake Iroquois shoreline at Whitevale Road. This shallow aquifer is not present south of the Lake Iroquois shoreline. The deep Thorncliffe and Scarborough aquifer complexes are mapped throughout the watershed and occur at shallower depth south of the Lake Iroquois shoreline (Whitevale Road) as the ground surface elevation is lower due to erosion of overlying deposits by Glacial Lake Iroquois. Estimated groundwater recharge over the South Slope till plain ranges from 60 to 90 mm/year. Recharge along the Lake Iroquois shoreline/beach (sand and gravel) is estimated at 180 mm/year. Recharge over the Lake Iroquois plain deposits is estimated to range from 36 to 90 mm/year. Based on numerical groundwater flow modelling, the average recharge rate for the Carruthers Creek watershed is estimated at 118 mm/year with the total average annual groundwater discharge to streams estimated at 130 mm/year. For comparison, the minimum estimated baseflow at the HY013 Carruthers Creek at Achilles streamflow gauge is 105 mm/year for the period 2008 to 2016. No municipal supplies from groundwater exist within the watershed. The southern part of the watershed from Lake Ontario north to Taunton Road is serviced by municipal water supplies from Lake Ontario. Water supply in rural areas north of Taunton Road is obtained from wells for private homes and farms. Some data gaps exist relative to hydrogeology within the Carruthers Creek watershed. These gaps include: • No Carruthers watershed locations for monitoring of groundwater levels; • No Carruthers watershed locations for monitoring of groundwater quality; and • No Carruthers watershed focused analysis of possible impacts from various potential land use scenarios (groundwater flow modelling). These data gaps are anticipated to be addressed during Phase 2 of this Watershed Plan update. The installation of a groundwater monitoring nest north of Hwy 407 at the south end of Balsam Road (east of Salem Road) is in the planning phase. Also, various possible land use scenarios will be analysed from a water budge perspective utilizing an v02: July 25, 2017 Page 64 of 77 TRCA Carruthers Creek – Hydrogeology existing numerical groundwater flow model. Changes to this preferred model are anticipated to largely relate to refinement of the calibration utilizing updated historical streamflow data and groundwater levels. v02: July 25, 2017 Page 65 of 77 TRCA Carruthers Creek – Hydrogeology 5.0 REFERENCES Anderson, T.W. and C.F.M. Lewis. 1985. Postglacial water-level history of the Lake Ontario basin. In Quaternary Evolution of the Great Lakes, edited by P.F. Karrow and P.E. Calkin, Geological Association of Canada Special Paper 30, 231-253. Baker, C.L., L.R. Lahti and D.C. Roumbanis. 1998. Urban Geology of Toronto and Surrounding Area. In Urban Geology of Canadian Cities. Edited by P.F. Karrow and O.L. White. Geological Association of Canada Special Paper 42, 323-352. Barnett, P.J. 1990. Tunnel valleys: evidence of catastrophic release of subglacial meltwater, central-southern Ontario, Canada. In Abstracts with Programs, Northeastern Section, Geological Society of America, Syracuse, New York, p. 3. Barnett, PJ. 1992. Quaternary Geology of Ontario. In Geology of Ontario, Ontario Geological Survey, Ontario Ministry of Northern Development and Mines, Edited by PC Thurston, HR Williams, RH Sutcliffe and GM Stott. Special Volume 4, Part 2, Chapter 21, 1011-1088. Barnett, P.J., W.R. Cowan and A.P. Henry. 1991, Quaternary geology of Ontario, southern sheet. Ontario Geological Survey, Map 2556, scale 1: 1 000 000. Barnett, P.J., D.R. Sharpe, H.A.J. Russell, T.A. Brennand, G. Gorrell, F. Kenny, and A. Pugin. 1998. On the origins of the Oak Ridges Moraine. Canadian Journal of Earth Sciences, vol. 35, pp. 1152 – 1167. Boyce, J.I. 1997. Facies architecture and stratigraphic heterogeneity in glacial deposits and their relation to hydrogeologic function. Ph.D. thesis, University of Toronto. Boyce, J.I., N. Eyles and A. Pugin. 1995. Seismic reflection, borehole and outcrop geometry of Late Wisconsin tills at a proposed landfill near Toronto, Ontario. Canadian Journal of Earth Sciences, v. 32, p.1331-1349. Bradbury, K.R. and E.R. Rothschild. 1985. A computerized technique for estimating the hydraulic conductivity of aquifers from specific capacity data. Ground Water, 23(2), 240-246. Brennand, T. A., C. Logan, F. Kenny, A. Moore, H.A.J. Russell, D.R. Sharpe and P.J. Barnett. 1997. Bedrock Topography of the Greater Toronto and Oak Ridges Moraine NATMAP areas, southern Ontario; Geological Survey of Canada Open File 3419, scale 1:200 000. Brennand, T., and J. Shaw. 1994, Tunnel channels and associated landforms: their implication for ice sheet hydrology. Canadian Journal of Earth Sciences, v. 31, p. 502-522. Brookfield, M.E., Q.H.J. Gwyn and P.I. Martini. 1982, Quaternary sequences along the north shore of Lake Ontario: Oshawa-Port Hope. Canadian Journal of Earth Sciences, v, 19, p. 1836-1850. v02: July 25, 2017 Page 66 of 77 TRCA Carruthers Creek – Hydrogeology Brown, D.M., McKay, G.A. and Chapman, L.J. 1980, The Climate of Southern Ontario. Climatological Studies, Number 5: Environment Canada, Atmospheric Environment Service. Central Lake Ontario Conservation Authority (CLOCA). 2007. Interim Watershed Characterization Report , CLOCA Watersheds, Part of the Source Water Protection Plan Program for the CTC Region, March 12, 435p. Central Lake Ontario Conservation Authority (CLOCA). 2008. Lynde Creek Watershed Existing Conditions Report Chapter 14 – Hydrogeology. June, 47p. CH2M Hill Canada Limited. 2009. Geological and Hydrogeological Environment Existing Environmental Conditions Technical Support Document New Nuclear- Darling Environmental Assessment. Prepared for Ontario Power Generation Inc., September, 739p. Chapman, L.J. 1985. On the origin of the Oak Ridges Moraine, southern Ontario. Canadian Journal of Earth Sciences, v. 22, p. 300-303. Chapman, L.J. and D.F. Putnam. 1984. The Physiography of Southern Ontario, 3rd Edition. Ontario Geological Survey, Special Volume 2. Chapman, T.G. and A.I. Maxwell. 1996. Baseflow separation – comparison of numerical methods with tracer experiments. Institute Engineers Australia National Conference, Publ. 96/05, 539-545. Clarifica Inc. 2002. Water Budget in Urbanizing Watersheds: Duffins Creek Watershed. Prepared for the Toronto and Region Conservation Authority, May 21, 2002. Coffey Geotechnics Inc. 2011. Draft Geotechnical Data Report, Preliminary Geotechnical Investigation for Twin Tunnels, Eglinton Crosstown Light Rail Transit. Prepared for the Toronto Transit Commission, March, 1653p. Conestoga Rovers and Associates. 2003. York Peel Durham Groundwater Management Strategy Study, Aquifer Characterization Study, Stream Baseflow Assessment Program. Prepared for the Conservation Authorities Moraine Coalition, May. Deane, R.E. 1950, Pleistocene geology of the Lake Simcoe district, Ontario. Geological Survey of Canada, Memoir 256. Duckworth, P.B. 1979. The late depositional history of the western end of the Oak Ridges Moraine, southern Ontario. Canadian Journal of Earth Sciences, v. 16, p.1094-1107. Earthfx Inc. 2006. Regional Ground Water Modelling of the Oak Ridges Moraine and TRCA Watersheds. Prepared for the Conservation Authorities Moraine Coalition, February. v02: July 25, 2017 Page 67 of 77 TRCA Carruthers Creek – Hydrogeology Earthfx Inc. 2007. Wellhead Protection Area Study for Municipal Residential Groundwater Systems Located within the TRCA watersheds, Caledon East Wells 2, 3 and 4 and Palgrave Wells 2 and 3. October. 119p. Earthfx Inc. 2009a. SPC Accepted Tier 1 Water Budget Central Lake Ontario Source Protection Area, February, 181p. Earthfx Inc. 2009b. Simulation of Groundwater Flow in the Regional Municipality of Durham. September. 134p. Earthfx Inc. 2011. Water Budget Modelling for the Oak Ridges Moraine Conservation Plan in the CLOCA Area, March, 117p. Earthfx Inc. 2014a. Ecologically Significant Groundwater Recharge Area Delineation in the CLOCA Area. May, 56p. Earthfx Inc. 2014b. Tier 3 Water Budget and the Local Area Risk Assessment for the Region of York Municipal Systems, Risk Assessment Report. December, 954p. Eckhardt, K. 2005. How to construct recursive digital filters for baseflow separation. Hydrological Processes 19, 507-515. Eyles, N.E. 1987. Late Pleistocene depositional systems of Metropolitan Toronto and their engineering and glacial geological significance. Canadian Journal of Earth Sciences, 24, p.1009-1021. Eyles, N. 1997. Chapter 2. Environmental Geology of a Supercity: The Greater Toronto Area. In Eyles, N. (Ed), Environmental Geology of Urban Areas, Geological Association of Canada, Geotext #3, 7-80. Eyles, N. 2002. Ontario rocks: three billion years of environmental change. Fitzhenry and Whiteside, Markham, Ontario. Eyles, N., J. Boyce, and A.A. Mohajer. 1993. The bedrock surface of the western Lake Ontario Region: Evidence of reactivated basement structures. Geographie physique et Quaternaire, 1993, vol. 47, N. 3, pp 269-283. Eyles, N. and B.M. Clark. 1988. Last interglacial sediments of the Don Valley Brickyard, Toronto, Canada, and their paleoenvironmental significance. Can. J. Earth Sci., 25, 1108-1122. Eyles, C.H. and N. Eyles. 1983. Sedimentation in a large lake: A reinterpretation of the late Pleistocene stratigraphy of Scarborough Bluffs, Ontario, Canada. Geology, v.11, p.146-152. Eyles, N., B.M. Clark, B.G. Kaye, K.W.F. Howard and C.H. Eyles. 1985. The application of basin analysis techniques to glaciated terrains: an example from the Lake Ontario basin, Canada. Geoscience Canada, v. 12, p. 22-32. v02: July 25, 2017 Page 68 of 77 TRCA Carruthers Creek – Hydrogeology Gartner Lee Limited. 2003. Durham Region Groundwater Use Assessment Report 2. Prepared for the Region of Durham. June 27th, 57p. Gerber, R.E. 1994. Recharge analysis for the central portion of the Oak Ridges Moraine. Unpublished M.Sc. thesis, University of Toronto. Gerber, R.E. 1999. Hydrogeologic behaviour of the Northern till aquitard near Toronto, Ontario. Ph.D. thesis, University of Toronto, 172p. Gerber, R.E., and K.W.F. Howard. 1996. Evidence for recent groundwater flow through Late Wisconsinan till near Toronto, Ontario. Canadian Geotechnical Journal, v. 33, p. 538-555. Gerber, R.E. and K.W.F. Howard. 2000. Recharge through a regional till aquitard: three- dimensional flow model water balance approach. Ground Water, 38 (3), 410-422. Gerber, R.E. and K. Howard. 2002. Hydrogeology of the Oak Ridges Moraine aquifer system: implications for protection and management from the Duffins Creek watershed. Canadian Journal of Earth Sciences, 39, 1333-1348. Gerber, RE, J.I. Boyce and K.W.F. Howard. 2001. Evaluation of heterogeneity and field-scale groundwater flow regime in a leaky till aquitard. Hydrogeology Journal, 9 : 60-78. Gerber Geosciences Inc. 2003. Duffins Creek Watershed: Hydrogeology and Assessment of Land Use Change on the Groundwater Flow System. Prepared for the Toronto and Region Conservation Authority. March 10. Gilbert, R. 1997. Glaciolacustrine sedimentation in part of the Oak Ridges Moraine, Géographie Physique et Quaternaire, 7(1): 55-66. Golder Associates Ltd. 2006. Geotechnical Investigation, Spadina Subway Extension Environmental Assessment, City of Toronto. Prepared for Toronto Transit Commission, January, 85p. Golder Associates Ltd. 2013. York Tier Three Project Groundwater Flow Model File Conversion. Technical Memo to York Region, November 25. Golder Associates Ltd. 2013b. Review of the York Tier Three Project – Phase 1 Model Data Release Files. Technical Memo to York Region, November 25. Golder Associates Ltd. 2015. York Region Wellhead Protection Area (WHPA) Replication Project. Technical Memo to York Region, July 3. Graham, EI, HR Whiteley and NR Thomson. 1997. Development and initial refinement of a water balance model as a planning tool for stormwater management application. Advances in Modeling and Management of Stormwater Impacts, Vol. 5, W James (editor). Published by CHI, Guelph, Canada. v02: July 25, 2017 Page 69 of 77 TRCA Carruthers Creek – Hydrogeology Gwyn, Q.H.J. 1976. Quaternary geology and granular resources of the eastern part of the Regional Municipality of Durham (parts of Reach, Whitby , east Whitby, Cartwright, Darlington, and Clarke townships), southern Ontario. Ontario Division of Mines, Open File Report 5176. Gwyn, Q.H.J. and W.R. Cowan. 1978. The origin of the Oak Ridges and Orangeville moraines of southern Ontario. Canadian Geographer, XXII, v. 4, p. 345-351. Haefeli, C.J. 1970, Regional groundwater flow between Lake Simcoe and Lake Ontario. Department of Energy, Mines and Resources, Inland Waters Branch Technical Bulletin 23. Hicock, S.R. and A. Dreimanis. 1989. Sunnybrook drift indicates a grounded, early Wisconsin glacier in the Lake Ontario basin. Geology, 17, 169-172. Hinton, MJ. 1996. Measuring stream discharge to infer the spatial distribution of groundwater discharge. In Proceedings of the Watershed Management Symposium, Canada Centre for Inland Waters, Burlington, Ontario. Canada. December 6-8, 1995, 27-32. Holden, K.M., J. Thomas and P.F. Karrow. 1993a. Bedrock topography, Oshawa area, southern Ontario. Ontario Geological Survey, Preliminary Map P.3192, Scale 1:50,000. Holden, K.M., J. Thomas and P.F. Karrow. 1993b. Bedrock topography, Barrie area, southern Ontario. Ontario Geological Survey, Preliminary Map P.3212, Scale 1:50,000. Holden, K.M., J. Thomas and P.F. Karrow. 1993c. Bedrock topography of the Alliston area, southern Ontario. Ontario Geological Survey, Preliminary Map P.3213, Scale 1:50,000. Holden, K.M., J. Thomas and P.F. Karrow. 1993d. Bedrock topography, Newmarket area, southern Ontario. Ontario Geological Survey, Preliminary Map P.3214, Scale 1:50,000. Howard, K.W.F., and P. Beck. 1986, Hydrochemical interpretation of groundwater flow systems in Quaternary sediments in southern Ontario. Canadian Journal of Earth Sciences, v. 23, p. 938-947. Howard, K.W.F., N. Eyles, P. Smart, J. Boyce, R.E. Gerber, S.L. Salvatori and M. Doughty. 1997. The Oak Ridges Moraine of southern Ontario: a ground-water resource at risk. In N. Eyles editor, Environmental Geology of Urban Areas, Geological Association of Canada, pp.153-172. Hunter and Associates and Raven Beck Environmental Ltd. 1996. Hydrogeological evaluation of the Oak Ridges Moraine area: technical report. Part of Background Report 3 for the Oak Ridges Moraine Planning Study. Prepared for the Oak Ridges Moraine Technical Working Committee. v02: July 25, 2017 Page 70 of 77 TRCA Carruthers Creek – Hydrogeology Institute of Hydrology. 1980. Low Flow Studies report. Wallingford, UK. Interim Waste Authority. 1993a. IWA landfill site search, Peel Region, Step 6 hydrogeological report Site B-15b. Prepared by Golder Associates Ltd., December. Interim Waste Authority. 1993b. IWA landfill site search, Peel Region, Step 6 hydrogeological report Site B-21c. Prepared by Golder Associates Ltd., December. Interim Waste Authority. 1993c. IWA landfill site search, Peel Region, Step 6 hydrogeological report Site B-22d. Prepared by Golder Associates Ltd., December. Interim Waste Authority. 1993d. IWA landfill site search, Peel Region, Step 6 hydrogeological report Site C-48. Prepared by Golder Associates Ltd., December. Interim Waste Authority. 1994a. EA document IV, geology/hydrogeology, technical appendix 1: Site T1 for Durham Region landfill site search. Prepared by M.M. Dillon Limited, February, 1994. Interim Waste Authority. 1994b. EA document IV, geology/hydrogeology, technical appendix 2: Site EE4 for Durham Region landfill site search. Prepared by M.M. Dillon Limited, February, 1994. Interim Waste Authority. 1994c. EA document IV, geology/hydrogeology, technical appendix 3: Site EE10 for Durham Region landfill site search. Prepared by M.M. Dillon Limited, February, 1994. Interim Waste Authority. 1994d. IWA landfill site search, Metropolitan Toronto/York Region, Step 6 hydrogeological report Site M6. Prepared by Fenco MacLaren Inc, February 1994. Interim Waste Authority. 1994e. Detailed assessment of the proposed site EE11 for Durham Region landfill site search, Technical appendices Parts 1 and 3 of 4. Prepared by M.M. Dillon Limited, October 1994. Interim Waste Authority. 1994f. EA Document IV, Geology/Hydrogeology, Technical Appendix 5: Site KK2. Prepared by M.M. Dillon Limited, February 1994. Interim Waste Authority. 1994g. Detailed assessment of the proposed site V4A for Interim Waste Authority Metropolitan Toronto/York Region landfill site search, Appendix C. Prepared by Fenco MacLaren Inc., November, 1994. Interim Waste Authority. 1994h. IWA landfill site search, Metropolitan Toronto/York Region, Step 6 hydrogeological report Sites G1B, G1C. Prepared by Fenco MacLaren Inc, February 1994. Interim Waste Authority. 1994i. IWA landfill site search, Metropolitan Toronto/York Region, Step 6 hydrogeological report Sites V3B, V4A, V4D. Prepared by Fenco MacLaren Inc, January, 1994. v02: July 25, 2017 Page 71 of 77 TRCA Carruthers Creek – Hydrogeology Interim Waste Authority. 1994j. Detailed assessment of the proposed site C-34B for Interim Waste Authority Peel Region landfill site search, Appendix C. Prepared by Golder Associates Ltd., November, 1994. Johnson M.D., D.K. Armstrong, B.V. Sanford, P.G. Telford and M.A. Rutka. 1992. Paleozoic and Mesozoic Geology of Ontario. In : Geology of Ontario, Edited by P.C. Thurston and others, Ministry of Northern Development and Mines, 907-1010. Karrow, PF. 1967. Pleistocene geology of the Scarborough area. Ontario Geological Survey, Report 46, Ontario Department of Mines. Karrow, P.F. 1970. Bedrock Topography, Thornhill Area, York County. Ontario Department of Mines, Preliminary Map P.574, Scale 1 :25,000. Karrow, P.F. 1989. Quaternary geology of the Great Lakes subregion. In Chapter 4, Quaternary Geology of Canada and Greenland. Edited by J.O. Wheeler, Geological Survey of Canada, Geology of Canada, v. 1, pp. 326-350. Kelley, R.I. and I.P. Martini. 1986. Pleistocene glacio-lacustrine deltaic deposits of the Scarborough Formation, Ontario, Canada. Sedimentary Geology, 47, 27-52. Li. Q., A.J.A. Unger, E.A. Sudicky, D. Kassenaar, E.J. Wexler and S. Shikaze. 2008. Simulating the multi-seasonal response of a large-scale watershed with a 3D physically-based hydrologic model. Journal of Hydrology, 357, 317-336. Markstrom, S.L., R.G. Niswonger, R.S. Regan, D.E. Prudic and P.M. Barlow. 2008. GSFLOW – Coupled Ground-water and Surface-water FLOW model based on the integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005). U.S. Geological Survey Techniques and Method 6-D1, 240 p. Martini, I.P. and M.E. Brookfield. 1995. Sequence analysis of upper Pleistocene (Wisconsinan) glaciolacustrine deposits of the north-shore bluffs of Lake Ontario, Canada. Journal of Sedimentary Research, v. B65 (3), p. 388-400. McDonald, M.G. and A.W. Harbaugh. 1988. Chapter A1: A modular three-dimensional finite-difference ground-water flow model, Book 6 modeling techniques. Techniques of Water-Resources Investigations of the United States Geological Survey. Meriano, M. 1999. Hydrogeology of a complex glacial system, Rouge River – Highland Creek Watershed, Scarborough, Ontario. Unpublished M.Sc. thesis, University of Toronto. Meriano, M. 2007. Groundwater-Surface water interaction in Frenchman’s Bay watershed, Ontario: implications for urban recharge, contaminant storage and migration. PhD thesis, University of Toronto,.218p. MM Dillon Limited. 1990. Regional Municipality of Durham Contingency Landfill Site Assessment Technical Support Volume B, Technical Report, Hydrogeology. September 1990. v02: July 25, 2017 Page 72 of 77 TRCA Carruthers Creek – Hydrogeology Morton, FI. 1983. Operational estimates of areal evapotranspiration and their significance to the science and practice of hydrology. Journal of Hydrology, 66, 1-76. Mowatt, GD. 2000. A finite element groundwater flow model analysis of the glacial stratigraphy of the Greater Toronto area. Unpublished M.Sc. thesis, University of Toronto. Nathan, R.J. and T.A. McMahon. 1990. Evaluation of automated techniques for baseflow and recession analysis. Water Resources Research, 26(7), 1456-1473. Nathan, R.J. and T.A. McMahon. 1991. Comment on the evaluation of automated techniques for baseflow and recession analysis. Water Resources Research, 27(7), 1783-1784. Ontario Geological Survey. 2006. 1:250,000 scale bedrock geology of Ontario. Ontario Geological Survey, Miscellaneous Release-Data 126-Revised. Ontario Geological Survey. 2010. Surficial geology of southern Ontario. Ontario Geological Survey, Miscellaneous Release – Data 128 – Revised. Ontario Ministry of Municipal Affairs and Housing (OMMAH). 2002. Oak Ridges Moraine Conservation Plan. 22 April. 73p. Ontario Ministry of Municipal Affairs and Housing (OMMAH). 2005. Greenbelt Plan. 63p. Ostry, RC. 1979. The Hydrogeology of the IFYGL Duffins Creek study area. Water Resources Report 5c, Ministry of the Environment, Water Resources Branch, Toronto, Ontario, 39p. Phillips, D.W. and McCulloch, J.A.W., 1972, The Climate of the Great Lakes Basin: Climatological Studies, Number 20, Environment Canada, Atmospheric Environment Service. Piggott, A.R., S. Moin and C. Southam. 2005. A revised approach to the UKIH method for the calculation of baseflow. Hydrological Sciences Journal, 50(5), 911-920. Pugin, A., S.E. Pullan and D.R. Sharpe. 1999. Sharpe Seismic facies and regional architecture of the Oak Ridges Moraine area, southern Ontario. Canadian Journal of Earth Sciences, 36 : 409-432. Pullan, S.E., A. Pugin, L.D. Dyke, J.A. Hunter, J.A. Pilon, B.J. Todd, V.S. Allen and P.J. Barnett, P.J. 1994. Shallow geophysics in a hydrogeological investigation of the Oak Ridges Moraine, Ontario. In Proceedings, symposium on the application of geophysics to engineering and environmental problems. Edited by Bell, R.S. and Lepper, C.M., March 27-31, Boston, Massachusetts, v. 1, p. 143-161. Rogers, D.P., R.C. Ostry and P.F. Karrow. 1961. Metropolitan Toronto Bedrock Contours. Ontario Department of Mines, Preliminary Map 102. v02: July 25, 2017 Page 73 of 77 TRCA Carruthers Creek – Hydrogeology Russell, H.A.J, R.W.C. Arnott and D.R. Sharpe. 2002. Evidence for rapid sedimentation in a tunnel channel, Oak Ridges Moraine, southern Ontario, Canada. Sedimentary Geology, 3134, 1-23. Russell, H.A.J., T.A. Brennand, C. Logan and D.R. Sharpe. 1998. Standardization and assessment of geological descriptions from water well records, Greater Toronto and Oak Ridges Moraine areas, southern Ontario. In Current Research 1998-E; Geological Survey of Canada, 89-102. Russell, H.A.J., D.R. Sharpe and W. Arnott. 1997, Sedimentology of the Oak Ridges Moraine, Humber River watershed, southern Ontario: a preliminary report. In Current research, Geological Survey of Canada, p. 155-166. Russell, H.A.J, D.R. Sharpe and C. Logan. 2002a. Structural Model of the Oak Ridges Moraine and Greater Toronto Areas, Southern Ontario : Halton Till. Geological Survey of Canada, Open File 4239, scale 1 :250,000. Russell, H.A.J, D.R. Sharpe and C. Logan. 2002b. Structural Model of the Oak Ridges Moraine and Greater Toronto Areas, Southern Ontario : Oak Ridges Moraine Sediment. Geological Survey of Canada, Open File 4240, scale 1 :250,000. Russell, H.A.J, D.R. Sharpe, T.A. Brennand, P.J. Barnett and C. Logan. 2003. Tunnel Channels of the Oak Ridges Moraine and Greater Toronto Area, Southern Ontario. Geological Survey of Canada, Open File 4485, scale 1 :250,000. Rutledge, A.T. 1998. Computer Programs for Describing the Recession of Ground-Water Discharge and for Estimating Mean Ground-Water Recharge and Discharge from Streamflow Records-Update. USGS Water Resources Investigation Report 98-4148. Sado, E., O.L. White, P.J. Barnett and D.R. Sharpe. 1984, The glacial geology, stratigraphy and geomorphology of the North Toronto area: a field excursion. In Correlation of Quaternary Chronologies. Edited by W. C. Mahaney, GeoBoooks, Norwich, pp. 505-517. Sharpe, D.R. and J. Clue. 1978. Bedrock topography of the Durham Area, Southern Ontario. Ontario Geological Survey Preliminary Map P.1836, Bedrock Topography Series, Scale 1 :50,000. Sharpe, DR, PJ Barnett, TA Brennand, D Finley, G Gorrell, HAJ Russel and P Stacey. 1997. Surficial Geology of the Greater Toronto and Oak Ridges Moraine Area, Southern Ontario; Geological Survey of Canada, Open File 3062, Scale 1:200,000. Sharpe, D.R., L.D. Dyke, M.J. Hinton, S.E. Pullan, H.A.J. Russell, T.A. Brennand, P.J. Barnett and A. Pugin. 1996. Groundwater prospects in the Oak Ridges Moraine area, southern Ontario: application of regional geological models. In Current Research 1996-E. Geological Survey of Canada, p. 181-190. Sharpe, D.R., L.D. Dyke and S.E. Pullan. 1994. Hydrogeology of the Oak Ridges Moraine: partners in geoscience, Geological Survey of Canada, Open File 2867. v02: July 25, 2017 Page 74 of 77 TRCA Carruthers Creek – Hydrogeology Sharpe, D.R., M.J. Hinton, H.H.J. Russell, and A. Desbarats, March, 2002. The Need for Basin Analysis in Regional Hydrogeological Studies, Oak Ridges Moraine, Southern Ontario. Geoscience Canada, Volume 29, Number 1. Sharpe, D.R., A. Pugin, S. Pullan and J. Shaw. 2004. Regional unconformities and the sedimentary architecture of the Oak Ridges Moraine area, southern Ontario. Canadian Journal of Earth Sciences, 41, 183-198. Sharpe, D.R., H.A.J. Russell and C. Logan. 2002a. Structural Model of the Oak Ridges Moraine and Greater Toronto Areas, Southern Ontario : Newmarket Till. Geological Survey of Canada, Open File 4241, scale 1 :250,000. Sharpe, D.R., H.A.J. Russell and C. Logan. 2002b. Structural Model of the Oak Ridges Moraine and Greater Toronto Areas, Southern Ontario : Lower Sediment. Geological Survey of Canada, Open File 4242, scale 1 :250,000. Shaw, J. and R. Gilbert. 1990. Evidence for large-scale subglacial meltwater flood events in southern Ontario and northern New York State. Geology, v. 18, p. 1169- 1172. Sibul, U, K.T. Wang and D. Vallery. 1977. Ground-Water Resources of the Duffins Creek-Rouge River Drainage Basins. Ontario Ministry of the Environment Water Resources Report 8, 109p. Sloto, R.A. and M.Y. Couse. 1996. HYSEP: A Computer Program for Streamflow Hydrograph Separation and Analysis. USGS Water Resources Investigations Report 96-4040. Smart, PJ. 1994. A water balance numerical groundwater flow model analysis of the Oak Ridges Aquifer Complex, south central Ontario. Unpublished M.Sc. thesis, University of Toronto. SooChan, G. 2006. Central Lake Ontario Conservation Authority groundwater resources study. Ontario Geological Survey, Groundwater Resources Study 1, 134p. Spencer, J.W., 1881. Discovery of the preglacial outlet of the basin of Lake Erie into that of Lake Ontario. Canadian Naturalist (New series), v. 10, p. 65-79. Spencer, J.W. 1890. Origin of the basins of the Great Lakes of America. Quarterly Journal of the Geological Society, 46, 523-533. Toronto and Region Conservation Authority (TRCA). 2002. Carruthers Creek State of the Watershed Report - Hydrogeology. June. Toronto and Region Conservation Authority (TRCA). 2003. A Watershed Plan for Duffins Creek and Carruthers Creek. August, 226p. v02: July 25, 2017 Page 75 of 77 TRCA Carruthers Creek – Hydrogeology Toronto and Region Conservation Authority (TRCA). 2007. Interim Watershed Characterization Report, TRCA Watersheds. Part of the Source Water Protection Plan Program for the CTC SWP Region. February 19th, 262p. Toronto and Region Conservation Authority (TRCA). 2010. SPC Accepted Tier 1 Water Budget, TRSPA Watersheds; Tier 2 for Little Rouge River and Stouffville/Reesor Creeks. September. 98p. Turner, M.E., 1978. Oak Ridges Aquifer Complex. Major Aquifers in Ontario Series, Ontario Ministry of the Environment, Hydrogeological Map 78-2, Scale 1 :100,000. Turner, M.E., 1977. Alliston Aquifer Complex. Major Aquifers in Ontario Series, Ontario Ministry of the Environment, Hydrogeological Map 77-1, Scale 1 :100,000. Watt, AK. 1957. Pleistocene geology and ground-water resources of the Township of North York, York County. Sixty-fourth annual report of the Ontario Department of Mines. Watt, AK. 1968. Pleistocene geology and ground-water resources, Township of Etobicoke. Ontario Department of Mines, Geological Report 59. White, OL. 1975. Quaternary geology of the Bolton area, southern Ontario. Geological Report 117, Ontario Division of Mines. Zaporozec, A. 1972. Graphical interpretation of water quality data. Ground Water, 10, 32-43. v02: July 25, 2017 Page 76 of 77