Hydrogeology
Hydrogeological Reviews
Submissions to Lake Simcoe Conservation Authority (LSRCA) are generally made under the Planning Act (insert link to planning section) for planning approvals or the Conservation Authorities Act and Ontario Regulation 41/24 for permits (insert link to regulations section). Other forms of submissions may include technical reviews. Please visit our Permit and Application Fees for a list of fees associated with various types of applications.
Hydrogeological Assessments are required to evaluate and mitigate the effects of urbanization on the groundwater regime. Urbanization increases impervious cover which, if left unmitigated, results in a decrease in infiltration. This infiltration decrease reduces groundwater recharge and soil moisture replenishment. It also reduces stream baseflow needed for sustaining aquatic life. Therefore, it is important to maintain the natural hydrologic cycle as much as possible. This will also reduce the potential for flooding and erosion. We have developed a hydrogeology submission checklist that is required to accompany the first development submission. ADD CHECKLIST?
Lake Simcoe Conservation Authority has a Memorandum of Understanding with local Municipal Partners to complete technical hydrogeological reviews of planning applications. The municipality is the approval agency and circulates the planning application to the LSRCA for technical hydrogeological review on their behalf. These reviews focus on groundwater recharge policies and assess whether infiltration is maintained from pre- to post-development. The hydrogeological review evaluates the Thornthwaite-Mather water balance analysis and the functional feasibility of the Stormwater Management Plan low-impact development strategies to mitigate the post-development infiltration deficit. The groundwater recharge policies and legislation include:
- Oak Ridges Moraine Conservation Plan (add link);
- Lake Simcoe Protection Plan (add link); and
- South Georgian Bay Lake Simcoe Source Protection Plan (add link).
Municipalities within the Authority’s watershed may have additional criteria beyond the above legislation and may undertake additional peer review services to address those different guidelines or criteria.
Vulnerable Areas and Policies
As part of the Memorandum of Understanding with local Municipalities, the Lake Simcoe Region Conservation Authority conducts hydrogeological reviews of planning applications technical reports based on groundwater recharge policies. The hydrogeological reviews are for major development* within specific vulnerable areas. These policies and areas include:
The objectives of the Oak Ridges Moraine Conservation Plan (ORMCP) include protecting, improving or restoring the ecological and hydrological integrity of the Oak Ridges Moraine area through land use planning. If the planning application is defined as major development there is a requirement to demonstrate how the quantity and quality of groundwater will be maintained post-development. A Hydrogeological Assessment and Water Balance analysis is required to demonstrate that the proposed major development will not have adverse effects on the hydrologically sensitive feature or related functions.
Planning applications are subject to the hydrogeological review of two Lake Simcoe Protection Plan Policies:
- Stormwater Management Policy 4.8-DP
Applies to all major development planning applications within the LSRCA watershed. The policy is to aid post-development stormwater management objectives by reducing runoff and increasing infiltration. A water balance analysis is required to demonstrate how these objectives are being met. It is important to note, if low impact development features are proposed to mitigate the water balance, then a scoped hydrogeological investigation (i.e., seasonal high groundwater levels and in-situ infiltration rates) is required.
- Recharge Policy 6.40-DP
Applies to major development planning applications within the watershed that are mapped within a Significant Groundwater Recharge Area (delineated through Source Water Protection) and/or an Ecologically Significant Groundwater Recharge Area (delineated through the Lake Simcoe Protection Plan). A Hydrogeological Assessment and Water Balance analysis is required to demonstrate the function of the recharge areas will be protected, improved or restored.
Planning applications are subject to the hydrogeological review of South Georgian Bay Lake Simcoe Source Protection Policy (SGBLSSPP) Land Use Policy 12 (LUP-12). LUP-12 applies to major development planning applications within a Well Head Protection Area -Q2 (WHPA-Q2), as delineated through the Source Protection Plan Teir 3 Risk Assessment for York Region. A Hydrogeological Assessment and Water Balance analysis is required to demonstrate that the existing water balance can be maintained through the use of best management practices, such as low impact development.
NEED TO ADD IMAGES
*note the definition of major development differs between ORMCP/LSPP and SGBLSSPP.
Hydrogeological Assessment and Water Balance analysis submitted as part of the planning application are to be prepared in such a manner that they are considered ‘stand-alone’. This means that the entire work can be recreated by any qualified person without the need to refer to any other material. Further, any qualified person (i.e., P.Geo. or exempted P.Eng. as per Professional Geoscientists Act (2000)) must be able to recognize and understand all the methods, approaches, basic data, interpretation, and rationale used.
The Hydrogeological Assessments are expected to provide new or updated sources of data, particularly on a local, site-specific scale and identify potential changes in groundwater and environmental conditions. Data provided should be of a qualitative and a quantitative nature and be suitable to identify a linkage between impact on recharge/discharge capability, long- and short-term watershed planning and environmental quality. Hydrogeological support of a planning application generally requires seasonal groundwater levels with a minimum of 12 continuous months of monitoring data, including the identified seasonally high groundwater elevation.
The Hydrogeological Assessment Submission Guidelines outlines the minimum hydrogeological study requirements in support of development applications. Provided in the Guideline is a checklist that will aid the Qualified Person in identifying the level of detail required to support the planning application.
LSRCA Technical Guidelines for Stormwater Management Submissions contain additional information relating to groundwater recharge, stormwater management and requirements for planning application submissions.
A water balance analysis is required for planning applications to estimate the pre-development and post-development infiltration and runoff. The water balance analysis provides mitigative targets for the planning application to have a net-zero change in pre-development infiltration. The maintenance of pre-development infiltration is a general requirement in the Oak Ridges Moraine Conservation Plan, Lake Simcoe Protection Plan, South Georgian Bay Lake Simcoe Source Protection Policy and the Provincial Policy Statement that is often captured in municipal Official Plans.
An accepted water balance analysis methodology is the Thornthwaite-Mather approach in conjunction with applying the infiltration factors provided in the Ministry of the Environment and Energy Hydrogeological Technical Information Requirements for Land Development Applications (1995). The Thornthwaite-Mather water balance analysis is to be completed by a qualified person (i.e., P.Geo. or exempted P.Eng. as per Professional Geoscientists Act (2000)) and included as part of the Hydrogeological Assessment, unless only LSPP 4.8-DP applies to the planning application.
A catchment-based water balance may also apply to the planning application. A catchment-based water balance is generally required for any development application adjacent to a Natural Heritage feature such as a wetland, woodlot, watercourse, or other protected area. Pre-consultation with LSRCA is highly recommended to scope both the general water balance and catchment-based water balance requirements which may overlap and be completed in conjunction with one another.
The LSRCA Technical Guidelines for Stormwater Management (insert link to SWM Guidelines) Submissions contain additional information relating to water balance and catchment-based water balance requirements for planning application submissions. The Hydrogeological Assessment Submission Guidelines provides an example of the Thornthwaite-Mather water balance analysis (add link).
The Hydrogeological Assessments are expected to provide new or updated sources of data, particularly on a local, site-specific scale and identify potential changes in groundwater and environmental conditions. Data provided should be of a qualitative and a quantitative nature and be suitable to identify a linkage between impact on recharge/discharge capability, long- and short-term watershed planning and environmental quality. Hydrogeological support of a planning application generally requires seasonal groundwater levels with a minimum of 12 continuous months of monitoring data, including the identified seasonally high groundwater elevation.
The Hydrogeological Assessment Submission Guidelines outlines the minimum hydrogeological study requirements in support of development applications. Provided in the Guideline is a checklist that will aid the Qualified Person in identifying the level of detail required to support the planning application.
LSRCA Technical Guidelines for Stormwater Management Submissions contain additional information relating to groundwater recharge, stormwater management and requirements for planning application submissions.
A Hydrogeological Assessment and Water Balance analysis is required to estimate the pre-development and post-development infiltration and runoff for most development applications within the Lake Simcoe Region Conservation Authority. The water balance analysis provides the post-development infiltration deficit and runoff surplus targets to be mitigated. A Stormwater Management Plan must make every feasible effort to maintain the pre-development infiltration and / or meet infiltration targets established in more comprehensive documents such as master plans, subwatershed plans and watershed plans, if applicable. Infiltration targets may be achieved through the incorporation of a variety of best management practices such as low impact development. Please see Sustainable Technologies Evaluation Program (Low Impact Development – Sustainable Technologies Evaluation Program (STEP)) for low impact development mitigation strategies related to infiltration.
The Technical Guidelines for Stormwater Management Submissions contain additional information relating to water balance and provide low impact development design guidance in support of mitigating the post-development infiltration deficit.
In the event that the pre-development infiltration cannot be met in the post-development conditions, the Water Balance Recharge Offsetting Policy, 2023 (insert link to WBOP) may apply in support of achieving the Lake Simcoe Protection Plan and South Georgian Bay Lake Simcoe Source Protection Plan targets for infiltration. To determine applicability of the Water Balance Recharge Offsetting Policy, the policy should be consulted in conjunction with authority pre-submission consultation.
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