Absorbent landscapes

STEP currently have a guide to amending and improving topsoil to improve the water retention capacity and promote healthy vegetation. I can be found here on our main website.

Soil amendment guidelines (from 2010 guide section 3 - placed here by Jen)

Soil amendment sizing criteria: impervious area / soil area = 1

• use 100 mm compost, till to 300 - 450 mm depth

impervious area / soil area = 2

• use 200 mm compost, till to 300 - 450 mm depth

impervious area / soil area = 3

• use 300 mm compost, till to 450 - 600 mm depth

Compost should consist of well-aged (at least one year) leaf compost. Amended soil should have an organic content of 8-15% by weight or 30-40% by volume. Source: Soils for Salmon, 2005

Info from Preserving and Restoring Healthy Soil: Best Practices for Urban Construction v 2.0 (placed by Jen)

1. Subsoil scarification (i.e., decompaction treatment) depth changes from minimum of 10 cm to 45 cm;
2. Topsoil/Planting Soil depth for tree pits changed from minimum of 60 cm to 20 cm;
3. Total uncompacted soil depth changed from 30 cm to 65 cm for turf/lawn and planting beds, and from 90 to 65 cm for tree pits;

Reference: Preserving and Restoring Healthy Soil: Best Practices for Urban Construction (TRCA 2012).

Tool and other info

Topsoil and Soil Amendment Calculator Spreadsheet Tool, V 2.0

Materials

• Topsoil
• Sand
• Compost

See also

• Downspout disconnection
• vegetated filter strips

Sustainable Technologies Evaluation Program

The practice of adding organic material, such as mulch or compost to topsoil to improve fertility, and tilling of the native soils to reverse compaction and restore its water retaining capacity.

A hard surface area (e.g., road, parking area or rooftop) that prevents or retards the infiltration of water into the soil.

Decayed organic material used as a plant fertilizer. Compost helps to support healthy plant growth through the slow release of nutrients and the retention of moisture in the soil.

Decayed organic material used as a plant fertilizer. Compost helps to support healthy plant growth through the slow release of nutrients and the retention of moisture in the soil.

Toronto and Region Conservation Authority