Site Alteration

The following is a brief and legal summary of the City of Markham's Site Alteration By-law taken from the City's By-law Guide for Markham Homeowners.

It explains, in plain language and with information links, what residents must know about specific City services and operations, which may affect a Markham homeowners' property.

Site Alteration By-law Summary

In Brief

This by-law was created to limit activities, such as removing or adding soil, which might change the level of a homeowner’s land. Changing the land’s surface, or grade, could interfere with the way water moves off your property. Water that can’t drain off can cause problems for yourself or your neighbour.

What You Must Know

The land you own, where your home sits, is called a lot and is designed with a two-foot swale around it. This shallow ditch, or depression in the ground, guides surface water safely off your property. It must be protected, along with the flow of natural waterways such as streams. This ensures that homes don’t experience flooding from Spring thaws or rainstorms and that yards don’t suffer from ponding or collected water that doesn’t go anywhere. See Water Use and Standing Water By-law Summary for more information about water on your property.

When homeowners plan new garden and landscaping projects, these swales must be preserved. The Site Alteration By-law ensures they are, but in general it doesn’t apply to lots smaller than one acre.

Note: If your lot, regardless of its size, is located beside water, environmentally protected or hazard lands, you need to be fully informed about this by-law: Contact the Building Standards Department, at 905.475.4870. This includes properties located on the Oak Ridges Moraine or other Conservation lands within the City of Markham.

Interfering with this slope is not allowed; anyone who does so will be required to restore, or pay the costs of restoring the original swale designed to drain the land and may be fined up to $10,000. See Property Standards By-law Summary for more information about water drainage.

If your lot is larger than the one-acre lots described above, a Site Alteration Permit is required for all work you are planning, except for simply filling in a hole up to the original level, or grade, of the land after removing a structure.

For this, and any building or major landscaping activities, you must contact the Engineering Department to discuss your plans before you proceed.

Step By Step

On lots smaller than one acre, a homeowner’s gardening activities must not create changes to the location, direction or elevation of any natural or artificial watercourse (such as open channels, swales and drainage ditches), and any potential sediment runoff must be controlled.

For lots greater than the one-acre lots, obtaining a Site Alteration Permit is a complex process that must involve a professional engineer. Refer all queries of this type to the Engineering Department.

Normal agricultural activity that moves up to 300 millimetre (just under 1 feet) of soil is exempted, such as sod farming, greenhouse operations and horticultural nurseries. However, if topsoil is being removed and taken away for sale, exchange or other purpose, the by-law applies and the owner must contact the By-law Enforcement and Licensing Department.

When in doubt, check it out! Help is always available.

For more information call the By-law Enforcement and Licensing Department at 905.479.7782 or email

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