Ponding water is the silent killer of commercial asphalt. In Ontario, where freeze-thaw cycles are aggressive, standing water doesn't just create a slip hazard: it compromises the structural integrity of your entire property. If your parking lot resembles a series of small lakes after a rainfall, the issue is rarely the asphalt itself; it is the grading.

At Reliance Engineering, we specialize in Site Grading Plans that move water exactly where it needs to go. Asphalt regrading is not a cosmetic fix; it is a precision engineering requirement for any functional commercial site.

The Cost of Poor Grading: Why Ponding Happens

Commercial parking lot drainage in Ontario fails when the surface loses its ability to shed water. Most "birdbaths" or ponding areas are the result of:

  • Subgrade Settlement: The ground beneath the asphalt has shifted, creating low spots.
  • Insufficient Slope: Many older lots were designed with slopes under 1%. In Ontario’s climate, a minimum of 2% is the standard for parking bays to ensure positive drainage.
  • Improper Tie-ins: Water becomes trapped against building foundations or curbs because there is no clear overland flow route.

Without commercial property grading fixes, water infiltrates the sub-base, expands when it freezes, and creates potholes that can't be fixed by a simple patch.

Precision Asphalt Regrading: The Drainage-Focused Approach

Effective drainage requires a drainage-focused approach during the design phase. We don’t just look at where the water is today; we design where it must go tomorrow.

Technical illustration of catch basin and 2 percent slope for positive drainage.

1. Identifying Overland Flow Routes

In any Stormwater Management Report, we identify major and minor drainage systems. Your asphalt must be graded to ensure that if a catch basin reaches capacity, the excess water follows a designed overland flow route away from buildings and toward a safe municipal outlet.

2. Implementing Practical Designs

We provide practical designs that contractors can actually build. This often involves:

  • Milling and Resurfacing: Removing the top layer of asphalt and resetting the grade to a proper 1.5% to 2% slope before repaving.
  • Strategic Catch Basin Placement: If a lot is too large to shed water to the perimeter, we integrate new catch basins at the absolute low points identified in our topographic survey.

Permit-Ready Drawings and Site Grading Plans

For any significant regrading or parking lot expansion, Ontario municipalities require stamped, permit-ready drawings. A professional Site Grading Plan from Reliance Engineering ensures your project meets the Ontario Building Code and local municipal standards.

Digital mockup of a professional Site Grading Plan for commercial development.

Our drawings include:

  • Existing and proposed elevations with precision contours.
  • Slope arrows indicating the direction of flow.
  • Detailed tie-ins to existing roads and municipal storm systems.
  • Functional Servicing Reports if new underground infrastructure is required.

Protecting the Site: Erosion and Sediment Control (ESC)

During any regrading project, the law requires you to prevent sediment from entering the municipal storm system. Our Erosion and Sediment Control Plans are designed to keep your project compliant.

Construction site showing silt fencing and catch basin protection.

A proper ESC plan includes catch basin protection and silt fencing to ensure that your asphalt regrading project doesn't result in municipal fines or environmental damage. This is a critical component of our Site Plan Approval (SPA) Drawings.

The Reliance Engineering Advantage

We take full ownership of your drainage challenges. With over 20 years of experience, we understand the specific requirements of municipalities across Ontario. We don't just provide drawings; we provide buildable grading solutions that save you from future litigation and maintenance costs.

Professional Credentials & Contact Information

For expert consultation on your commercial parking lot drainage or regrading project, contact:

Naresh Ochani, P.Eng. M.Eng.
Principal Engineer
Reliance Engineering Canada Limited
PEO Certificate of Authorization: 100548882

Office Hours:

  • Monday – Friday: 9:00 AM – 5:00 PM
  • Saturday: 12:00 PM – 2:00 PM
  • Sunday: Closed