Soil cells

Soil cells are underground systems that support urban trees and manage stormwater.

On this page

What is soil cells?
Benefits
Rebate eligibility and amount
Requirements
How to calculate your soil cell area
Examples of soil cells
Resources
Application and claim forms

What is soil cells?

Soil cells are plastic milk crate-like structures, which are filled with loose, specially blended soil, designed to be installed beneath hardscape surfaces. Soil cells collect stormwater through an inlet and distribute the stormwater through a perforated pipe into the loose soil, encouraging plant root growth and holding water during and after a rainfall. Stormwater not absorbed by the plants is filtered by the soil before going to the drainage system.

Benefits

Provide additional soil volume for tree roots to grow, resulting in flourishing trees with mature, expansive canopies that provide shade, cleaner air, and improved aesthetics.
Improve property drainage, as soil cells hold more water than regular sod lawns.
Help prevent sewer backups and flooding during heavy rain by slowing down and reducing the amount of stormwater entering the drainage system.

Rebate eligibility and amount

Eligibility

Multi-family residential
Industrial, commercial, and institutional

Amount

$11 per metre squared of directly connected impervious area (DCIA)

Note: The RainWise rebate program is not retroactive. Projects completed before the application is approved are not eligible for the rebates.

Requirements

To receive a RainWise rebate for soil cells, the following requirements must be met:

Receive runoff from an impervious surface (e.g. roof or parking lot).
Installed by a certified contractor and according to the manufacturer’s specifications.
Include some form of pre-treatment to prevent sediment and/or leaves from entering and clogging the soil cells (e.g. sump or catch basin).
Constructed a minimum of three (3) meters away from building foundations.
Must be sized to manage at least 75% of the directly connected impervious area as calculated in the soil cells sizing tool.
Must not contradict the City of Edmonton Drainage Bylaw. Here is some relevant information from the bylaw related to the release of water:

Roof and foundation drainage from a property is not permitted to be discharged:
- onto a pervious ground surface within one (1) meter of the building;
- within 150 mm of an adjacent lot;
- within 150 mm of a City of Edmonton right-of-way (ROW);
- to a location where the water has the potential to adversely impact slope stability, unstable ground, a ravine; or
- to a location or in a manner that causes or could cause nuisance, hazard or damage.

Make sure that you have all of the necessary photos and documents so that we can efficiently process your application and claim.

View guidelines for filling out your application.

Application form requirements

Before photos
Design sketch
Directly connected impervious area (DCIA)
Soil cells sizing tool (one for each individual soil cell installation)

Multi-family, industrial, commercial, and institutional customers if available, please include:

Storm servicing plans
Lot grading plans

Claim form requirements

Photos:

Completed work
After excavation
Before surface restoration. These photos must show installed underground components (e.g. soil cells modules) before they are covered with soil, plants, or other surface materials.

Keep all project related receipts. EPCOR reserves the right to request project-related receipts for all RainWise projects to verify project completion and ensure program compliance.

How to calculate your soil cell area

Use the Soil Cells Sizing Tool
Calculate based on how big your soil cell area needs to be to store the runoff generated from your directly connected impervious area (DCIA)
Aim to capture 100% of the runoff generated

Examples of soil cells

Resources

City of Edmonton Design and Construction Standards Volume 3-02

Application and claim forms

The rebate process has two steps. First, apply for approval before starting your project. Then, once approved and project is finished, submit your claim to receive your rebate.

Front view of a blue single‑storey home with a simple lawn and minimal landscaping before the RainWise yard transformation.

Application formFill out this form before you start your project. We need to approve your project first so it qualifies for the rebate.

Front yard of a blue single‑storey home transformed with lush plants, ornamental grasses, and sustainable landscaping features.

Claim formFill out this form after your project has been approved and fully completed.

Questions?

Your questions and feedback are important to us.

Contact EPCOR

Email: rainwise@epcor.com