Engineering

Development Engineering Reviews

Submissions to the Authority 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 refer to the Authority website for a list of fees associated with various types of applications.

Stormwater Management

Stormwater management is required to mitigate the effects of urbanization on the hydrologic cycle, including increased runoff and decreased infiltration of rain and snowmelt. Without proper stormwater management, increased flooding and erosion can occur.

As part of the implementation of the Lake Simcoe Protection Plan, the Lake Simcoe Region Conservation Authority conducts stormwater management reviews of technical reports as part of development applications. These reviews focus on reducing and controlling stormwater runoff volume and mimicking natural hydrology using treatment methods that include capture and re-use, using a wide variety of SWM and treatment methods.

Technical reports as part of development applications that include stormwater management 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.Eng., P.Geo., or C.E.T.) must be able to recognize and understand all the methods, approaches, basic data, and rationale used in the design calculations. A completed copy of the Stormwater management submission requirements checklist is required to accompany the first development submission. Link to checklist

The Technical Guidelines for Stormwater Management Submissions contain additional information relating to stormwater management and requirements for submissions.

Phosphorus Offsetting

Phosphorus is a nutrient, that, if present in excess quantities can lead to excessive growth of plants and algae. When the plants and algae decay, the decay process requires oxygen, reducing the amount of dissolved oxygen for fish. Stormwater contributes a significant amount of phosphorus into the tributaries and the lake and therefore this loading needs to be controlled. As such, the Lake Simcoe Protection Plan, dated 2009 requires that “An application for major development shall be accompanied by a SWM plan that demonstrates through an evaluation of anticipated changes in phosphorus loadings, between pre-development and post-development, how the loadings from the proposed development shall be minimized.

Phosphorus loading/removal calculations can be completed by the following methods:

M.O.E. Lake Simcoe Phosphorus Budget Tool, January 2012 (or subsequent versions) (available upon request)
Low Impact Development Treatment Train Tool – L.I.D. T.T.T. v2.2 (or subsequent versions) https://sustainabletechnologies.ca/lid-ttt/

The Technical Guidelines for Stormwater Management Submissions contain additional information relating to Phosphorus loading/removal calculations.

Furthermore, when the pre-development phosphorus loadings cannot be met in the post-development conditions, the Phosphorus Offsetting Policy (P.O.P.), 2023 may apply in support of achieving the Lake Simcoe Protection Plan targets for phosphorus loading. To determine applicability of the P.O.P., the policy should be consulted in conjunction with authority pre-submission consultation.

Floodplain Analysis

As the frequency and intensity of severe weather events continue to grow, establishing and maintaining accurate floodplain mapping is critical to public safety and to prevent the costs of property damages and business disruptions.

Floodplain mapping allows municipalities and conservation authorities to guide development away from flood-prone areas and supports better emergency management and planning.

As such, every effort should be made to keep proposed works and development outside of the floodplain. In some cases, this may not be possible. In those cases, the Authority should be pre-consulted about any proposed changes to the floodplain or works within the floodplain.

When dealing with proposed changes within the floodplain, (i.e cut/fill balance, watercourse crossings, etc.), it will need to be demonstrated that there are no negative impacts upstream or downstream in accordance with the Conservation Authorities Act and Ontario Regulation 41/24. Please note that the Authority Technical Guidelines for Stormwater Management Submissions and the Authority Conservation Authorities Act and Ontario Regulation 41/24 Implementation Guidelines need to be read in conjunction with each other. The Development and Engineering staff at the Lake Simcoe Region Conservation Authority remain available to assist with project-specific questions as they may arise.

Who to Contact