Stormwater Management Requirements for Land Development Proposals

Finalizing Construction and Operation Issues

Before proceeding with the tasks in this grouping, the following tasks should have been completed:

Before MTO can issue an approval for a land development proposal, the following tasks must be completed:

The MTO Regional Highway Planning and Design Office or the local MTO District Office may alter requirements presented in this document, since an extensive SWM report is not always required. MTO may make provisions to accept a drainage impact analysis that has a lower level of detail associated with it, provided that the proponent submits a plan showing how stormwater runoff from the proposed land development will be conveyed to the receiving drainage system. The proponent must be able to demonstrate that drainage impacts to the highway right-of-way or upstream/downstream riparian landowners will not occur, and that the capacity of the highway drainage system will not be exceeded as a result of stormwater runoff discharging from the proposed land development.


Providing Temporary Sediment and Erosion Control During Construction

Where applicable, MTO will require that a sediment and erosion control plan stamped by a Professional Engineer be submitted prior to final approval. Issues to be addressed are listed below. For further details on sediment and erosion control during construction, refer to Chapter 6 of the "Drainage Management Manual" (MTO 1997) and “Highway Drainage Design Standards” (MTO 2008).

  • Construction timing and the proposed construction timeframe and timing constraints for construction (spring, fall constraints) should be noted.
  • Construction phasing and timeframes for the different phases should be included. Indicate whether the entire site is to be developed all at once or whether the proposed land development is to be phased. Sediment control techniques must address both pre-serviced and serviced phases of construction.
  • Stabilization requirements and the allowable timeframe for land to remain exposed before it is stabilized with sod, mulch, or hydroseeding, should be noted. Indicate provisions for the stockpiling of soil.
  • Siltation fencing locations should be located at the site boundary at all side slope and down gradient locations. Siltation fence should also be used to protect significant features (i.e. provides a limit for grading activities) and to control dust, nuisance problems to homeowners in existing surrounding land developments.
  • Access/mud mat locations should be located at each entrance/exit location to the construction site. The mat can be removed once the access locations are paved. The number of access locations to a construction site should be minimized (1 or 2).
  • Catch-basin controls, where used, prevent the migration of sediment into the storm sewers.
  • Rock check dam locations should be located in overland swale systems which outlet to the receiving waters.
  • Siltation basins can be used to service larger drainage areas (stormwater detention facilities can be used as temporary sediment basins during construction, wherever possible).
  • Topsoil stockpile storage locations for soil storage piles and their distance from roads and drainage channels should be clearly shown. Timeframes and proposed works for the stabilization and remediation of topsoil stockpiles should be provided.
  • Inspection and maintenance requirements of the sediment and erosion control works should be noted. Maintenance should be performed as required to ensure the proper operation of sediment and erosion controls, and the works should be inspected after each storm to ensure proper operation.

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Clarifying Ownership, Operation and Maintenance Responsibilities

The MTO cannot issue final approval until responsibility for operation , maintenance and ownership of any drainage works has been clarified.

Documentation Required in SWM Report

The SWM report should document who will be assuming ownership and long-term maintenance responsibilities associated with the drainage work, to ensure that the drainage works will remain in good working order and function properly according to its original design. Long-term operation and maintenance responsibilities include costs.

Where required, the SWM report should also propose an appropriate legal mechanism, such as:

  • legal agreements with the municipality;
  • legal agreement with the owner;
  • conditions issued through a Building and Land Use or Encroachment Permit; or
  • conditions registered on title (site plan agreement or a subdivision agreement).

The MTO Regional Highway Planning and Design Office should be contacted for clarification. Refer to PHY Directive B014 for additional guidance. The following sections should also be reviewed.

Relevance to MTO

  • MTO will not assume the costs for any maintenance and operation associated with a drainage works that is not part of the highway drainage system.
  • MTO must clarify who should be contacted, legal or otherwise, in the event that repairs or maintenance is required to a drainage works.
  • MTO must ensure that appropriate legal mechanisms are in place to ensure future enforcement regarding operation and maintenance costs associated with the drainage works.

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