City of Barrie Secondary Plan, Background Studies & Infrastructure Master Plan Intensification & Annexed Lands

Draft Hydrogeologic Framework Technical Memorandum #1 Blackport and Associates

HYDROGEOLOGIC FRAMEWORK

TECHNICAL MEMORANDUM #1

DRAFT

Submitted to: The City of Barrie

Submitted by: Blackport & Associates

7839 County Road 45 Wallenstein, ON N0B 2S0

Tel: 519-698-0134

April 2012

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 i

TABLE OF CONENTS 1.0 INTRODUCTION ............................................................................................................. 1

1.1 Objective .............................................................................................................. 1 1.2 Study Area ........................................................................................................... 1

2.0 BACKGROUND REVIEW ................................................................................................ 2

2.1 Previous Studies .................................................................................................. 2 2.2 Scoped Groundwater Characterization Approach ................................................ 2

3.0 GEOLOGY ...................................................................................................................... 3

3.1 Bedrock Geology ................................................................................................. 3 3.2 Quaternary Geology ............................................................................................. 3

4.0 HYDROGEOLOGY.......................................................................................................... 4

Figures

Figure 1 Surficial Geology Figure 2 Cross Section and Borehole Locations Figure 2A Cross Section A-A’ Figure 2B Cross Section B-B’ Figure 2C Cross Section C-C’ Figure 2D Cross Section D-D’ Figure 2E Cross Section E-E’ Figure 2F Cross Section F-F’ Figure 2G Cross Section G-G’ Figure 2H Cross Section H-H’ Figure 2I Cross Section I-I’ Figure 3 Average Annual Recharge Figure 4 Upper Aquifer Water Table Figure 5 Depth to Upper Aquifer Water Table Figure 6A Potential Groundwater Discharge - West Figure 6B Potential Groundwater Discharge - East

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 1

1.0 INTRODUCTION 1.1 Objective The objective of this Technical Memorandum is to provide an overview of the groundwater characterization of the Annexation Lands. The understanding of the groundwater flow system and its ecosystem linkages will determine the hydrogeologic sensitivity at the study area scale which in turn, will direct future management strategies and the scope of future studies to protect the groundwater resources. 1.2 Study Area The groundwater characterization is mainly focused on the Annexed lands but the study area considers adjacent lands as the groundwater flow system of the annexed lands and adjacent lands are interconnected. The Annexed lands form two blocks separated by Huronia Road in the centre; the western and eastern blocks extend the previous urban boundary south to beyond McKay Road to Lockhart Road, respectively. The Annexed lands span five subwatersheds regulated by two conservation authorities, Nottawasaga Valley Conservation Authority (NVCA) and Lake Simcoe Region Conservation Authority (LSRCA). The westerly end of the western annex block is within the headwaters of Bear Creek and Thornton Creek, both tributaries of the Nottawasaga River and regulated by the NVCA. The easterly end of the western annex block and eastern annex block cut through the middle reaches of Lover’s Creek and Hewitt’s Creek, as well as the headwaters of Sandy Cove Creek, all tributaries to Lake Simcoe and regulated by the LSRCA.

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 2

2.0 BACKGROUND REVIEW 2.1 Previous Studies The background studies which were reviewed in support of groundwater characterization focused on source water protection. These were larger scale studies including: Updated Assessment Report: Lake Simcoe and Couchiching-Black River Source Protection Area Part 1: Lake Simcoe Watershed, South Georgian Bay-Lake Simcoe Source Protection Committee, 2011 Updated Assessment Report: Nottawasaga Valley Source Protection Area, Lake Simcoe Watershed, South Georgian Bay-Lake Simcoe Source Protection Committee, 2011 These reports provided large scale watershed characterization but were mainly focused on municipal water supplies, more specifically wellhead protection areas (WHPA), water budget and water quantity risk assessment and groundwater vulnerability. Large scale conceptual groundwater characterization was presented which supported the Tier 1 and Tier 2 Water Budget modeling. South Simcoe Groundwater Study WHPA-City of Barrie, Golder Associates, August 2004 This study was carried out for the South Simcoe Groundwater partnership which the City of Barrie is a member. The study focused on determining capture zones for various wells, estimated aquifer yields, presented Intrinsic Susceptibility Index (ISI) mapping for aquifer vulnerability and carried out a contaminant source inventory. City of Barrie Tier 3 Water Budget and Local Area Risk Assessment- Conceptual Understanding Memorandum, AquaResource Inc., December 2010 The Tier 3 study was carried out as a result of the Tier 2 study indicating the Barrie Creeks subwatershed as having a significant potential for water quantity stress. The Tier 3 study had a number of groundwater components including developing a more detailed three-dimensional conceptual geologic/hydrogeologic model, developing a three-dimensional groundwater flow model, developing a water budget and incorporating the most recent/local knowledge. The hydrogeologic cross-sections and the majority of the mapping has been developed from the Tier 3 model and database. The characterization and mapping as presented is limited to the extent of hydrogeologic data available and, as such, represents the larger scale conditions. Finer more local scale characterization may need to be confirmed or refined within future studies. 2.2 Scoped Groundwater Characterization Approach It was presented in the proposed work plan, to incorporate, if available, the Tier 3 Water Budget model into the groundwater characterization for the annexation lands. The Tier 3 study has incorporated the most recent data and has provided the most refined groundwater model for the study area. Utilization of this model base has been judged to be the best tool to provide the groundwater characterization related to the annexation lands. Select information from the above noted studies and the concurrent annexation land studies has also been incorporated into this preliminary characterization.

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 3

3.0 GEOLOGY 3.1 Bedrock Geology The predominant bedrock in the annexation lands and to the south is the limestone and shale of the Lindsay Formation. In the very eastern portion of the annexation lands, the bedrock is comprised of Veralum Formation which consists of a muddy to coarse grained limestone with shale interbeds. 3.2 Quaternary Geology The annexation lands and adjacent area lie within the Peterborough Drumlin Field physiographic region. The overburden deposits are a result of repeated advances and retreats of the Simcoe glacial ice lobe. Throughout, and adjacent to the annexation lands, the surficial deposits (Figure 1) consist of laterally discontinuous till sheets, which are more predominant east of Lovers Creek, stratified sand and gravel units (ice contact deposits, coarse grained glaciolacustrine deposits) in the western and north-eastern area and along the main branch and tributaries of local reaches of Lovers Creek. Organic deposits are predominant in the Lovers Creek Swamp to the south but within the annexation lands these deposits are associated with the St. Paul’s wetland and an area along Lover’s Creek south of Lockhart Road and West of Highway 400. The Surficial Geology map created for the Tier 3 study was based on data from the Ontario Geological Survey (OGS, 2003. Surficial Geology of Southern Ontario) The overburden thickness varies but can be up to 200 metres in the area of the Innisfil Highlands.

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 4

4.0 HYDROGEOLOGY 4.1 Conceptual Groundwater Flow System Water from precipitation percolates or infiltrates into the ground until it reaches the water table. Areas where water moves downward from the water table are known as recharge areas. These areas are generally in areas of topographically high relief. Areas where groundwater moves upward to the water table are known as discharge areas. These generally occur in areas of topographically low relief, such as stream valleys. Groundwater that discharges to streams is the water that maintains the baseflow of the stream. Wetlands may be fed by groundwater discharge. There are different types and rates of recharge and discharge. Water percolating into the ground at a specific location may discharge to a small stream a short distance away. This is local recharge and local discharge. Some water may recharge a certain area and discharge to a larger river basin a long way from the source of recharge. This is known as regional recharge and regional discharge. Permeable geologic materials through which groundwater moves are known as aquifers. Aquifers are "water bearing" formations meaning that water can be easily extracted from these units. The less permeable units are known as aquitards, and although water can move through these units, it moves slowly and it is difficult to extract water from these units. How these aquifers are connected within a hydrogeologic setting is what controls much of the movement of groundwater. A delineation of the flow system(s) in this way will identify where groundwater originates, where it discharges and the most prominent paths it travels between these points (e.g. the aquifer pathways or more permeable hydrostratigraphic units). Having done this, one can assess the relative sensitivity of the linkage from the groundwater system to the aquatic or terrestrial systems. Knowing the level of sensitivity of the receptor one can determine the potential impacts of particular types and scales of land uses or land use changes on the groundwater flow system and other linked ecosystem components.

Hydrostratigraphic Units

The quaternary deposits are the basic control for the study area groundwater flow system. The overburden consists of alternating sequences of coarser grained permeable units and finer grained less permeable units. These units have been interpreted as a sequence of aquifers and aquitards of varying thicknesses. Eight preliminary cross-sections have been created from the Tier 3 groundwater model. The locations can be found on Figure 2. These cross-sections are presented in Figures 2A-2I. The hydrostratigraphic unit layer structure presented on the cross-sections was developed in the Conceptual Understanding Report for the Tier 3 study. The units developed throughout South Simcoe and Source Water Protection studies utilized borehole geology derived mainly for the Water Well Information System database. The larger scale hydrostratigraphy consists of

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 5

eight major overburden units. Of the overburden units there are four main aquifer units (A1-A4) and four main aquitards (C1-C4) which constitute the numerical model layers within those studies. Furthermore, a confining layer (UC) over the uppermost aquifer A1, is present throughout the larger Barrie study area but exists in smaller thin pockets in the vicinity of the annexation lands study area. The following is a summary of the hydrostratigraphic units associated with the study area: UC – represents smaller areas of less permeable surficial material A1 – Represents the uppermost aquifer. Frequently exists as a surficial unconfined aquifer and is stratigraphically equivalent to the Oak Ridges Moraine. It is generally associated with coarse grained glacial and interglacial sediments mapped as ice contact stratified drift. The majority of the local domestic wells are within this unit. C1 – Upper aquitard. A2 – Intermediate aquifer which is stratigraphically equivalent to units within the Northern Till. This unit is used for Innisfil Heights water supply. C2 – Intermediate aquitard. A3 – This unit constitutes the main Barrie municipal aquifer and is the source of the Stroud water supply. C3 – Lower aquitard. A4 – Lower aquifer, thin and sometimes combined with A3 where C3 is thin or absent. C4 – Lower aquitard but may also represent weathered bedrock (ie modeled with a higher permeability). (NOTE: Further assessment of the cross-section unit thicknesses, based on existing model layer hydraulic conductivity discretization, will be carried out to refine the cross-section unit boundary layers). Recharge The permeability of the surficial deposits allows for various amounts of infiltration and subsequent recharge to lower hydrostratigraphic units. Recharge values from the Tier 3 MIKE-SHE model are presented in Figure 3. The higher recharge values can be readily correlated with the more permeable surficial sediments in Figure 1 with recharge values potentially greater than 400 mm/year.

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 6

Groundwater Flow Given the multi-aquifer setting described above and the potential high levels of recharge it is expected that the more dominant groundwater flow paths, within a ecosystem groundwater functional context, will be within the upper aquifer. Water table elevation contours where refined on a local scale from the Tier 3 database for the annexation lands and are presented in Figure 4. The contours reflect groundwater flow moving from the topographic high recharge areas of the Innisfil Highlands on the west annexation lands towards Lovers Creek. Groundwater flow appears to be focused on the main branch of Lovers Creek and a number of tributaries which are classified as coldwater stream (Natural Heritage Systems Framework report, June 2011). Groundwater flow from a water table high in the vicinity of Stroud also appears to be focused around the coldwater portion of Hewitts Creek which is also classified as a coldwater stream. It is possible that this system also provides a limited amount of groundwater discharge to Bear Creek and Sandy Cove Creek. In addition, it is expected that these same shallow groundwater flow systems supply groundwater discharge to the local wetlands including the lower portion of the Lovers Creek Swamp and the St. Pauls Swamp. A map of the depth to the water table in the Upper Aquifer is presented in Figure 5. This map is created by subtracting the water table from the ground surface elevations and is another way of presenting possible recharge and discharge areas. The areas of deeper water table tend to reflect more significant larger scale recharge in the upland areas. It should be noted that significant recharge in the more local groundwater flow systems may not be as evident in a depth to water table map of this scale. Figure 5 also shows areas of a “perched water table”. A perched water table is a larger zone that contains water saturated sediments overlying an unsaturated zone. The less permeable surficial sediments can hold or perch the very shallow groundwater above the deeper water table in the Upper Aquifer. These areas of perched water can provide for shallow, local groundwater flow which may support local wetlands or stream reaches to a limited extent. Figures 6A and 6B provide a qualitative graphic of general areas for potential groundwater discharge which were interpreted within this study based on a combination of the following factors: • Interpreted coldwater reaches • Permeable streambed sediments • Shallow water table

Within these areas groundwater is likely restricted to small spatial areas usually within or immediately adjacent to the stream. Within the wetlands the discharge is likely also spatially restricted. It all cases the amount of discharge will vary depending on the seasonal changes in local groundwater levels.

City of Barrie Hydrogeologic Framework Technical Memorandum #1 April 2012

Project Number: TP110135 7

Groundwater Quantity and Quality The extent and permeability of the various aquifers provides for large quantities of groundwater. The majority of individual groundwater supply usage is for private domestic wells. As discussed previously the majority of private domestic wells within the study area are screened in the upper aquifer. This can be readily seen on the cross-sections. The upper aquifer may have slightly less groundwater quantity when compared to the lower aquifers as a result of less saturated thickness or areas where there are inclusions of finer grained material. Innisfil Heights to the south obtains its water from the intermediate aquifer (A2). The Stroud water supply obtains water from the lower aquifer (A3). Golf course irrigation is another major water use but the local water takings appear to be sourced in ponds. Depending on how the ponds are constructed these sources may act as large shallow dug wells. The aquifer vulnerability or intrinsic susceptibility index commonly reflects the contaminant potential to an aquifer. Within the South Simcoe Groundwater Study the contaminant susceptibility is considered low for the municipal aquifer because the overlying protective low permeability aquitards. The contaminant potential for the shallow unconfined aquifer is high and as discussed above this is correlated with the high permeability surficial sediments. Groundwater quality data within the annexation area was not found during the background review. It is expected there may some local quality degradation resulting from, agricultural practices, road salting or historical spills. Groundwater Management The following should be considered for future groundwater management planning: • Efforts should be made to maintain or enhance the volume of recharge in areas of

permeable surficial overburden where the water table permits. These characteristic areas would be confirmed during site specific studies. Site specific studies would also refine the more local hydrogeologic connections to creek reaches or wetlands which may require more localized recharge needs to maintain groundwater discharge.

• BMP’s to address stormwater recharge should be designed to provide for an acceptable

water quality prior to recharging any local aquifer systems in order to protect the overall groundwater quality integrity of well users adjacent to the annexation lands.

• Bringing water from outside subcatchment areas or the subwatersheds can increase

local recharge and potential groundwater discharge. • Locations of services can short-circuit groundwater flow through the permeable underfill,

where the water table is higher, and may modify local groundwater flow systems, so site specific field assessment and design should be carried out to protect groundwater which maintains local discharge.

Bill Blackport, M.Sc., P.Geo.