1.11 BMP C124 - Sodding
The purpose of sodding is to establish turf for immediate erosion protection and to stabilize conveyance systems where concentrated overland flow will occur.
Sodding may be used in the following areas:
Disturbed areas that require short-term or long-term cover.
Disturbed areas that require immediate vegetative cover.
All waterways that require vegetative lining. Waterways may also be seeded rather than sodded, and protected with a net or blanket.
1.11.3 Design and Installation Specifications
Sod shall be free of weeds, of uniform thickness (approximately 1-inch thick), and shall have a dense root mat for mechanical strength.
The following steps are recommended for sod installation:
Shape and smooth the surface to final grade in accordance with the approved grading plan. Overexcavate areas as needed to allow room for placing soil amendment and sod.
Amend 4 inches (minimum) of compost into the top 8 inches of the soil if the organic content of the soil is less than ten percent or the infiltration rate is less than 0.6 inches per hour. Compost used shall:
Meet the definition for “composted material” per WAC 173-350-100 and comply with standards in WAC 173-350-220, except the feedstock may contain biosolids or manure feedstocks.
Have no visible water or dust during handling.
Have soil organic matter content of 40% to 65%.
Have a carbon to nitrogen ratio below 25:1. Carbon to nitrogen ratio may be as high as 35:1 for plantings composed entirely of plants native to the Puget Sound Lowlands region.
City of Tacoma Tagro Potting Soil can be used as an alternative to the compost component in BMP C124 - Sodding.
Fertilize according to the supplier's recommendations.
Work lime and fertilizer 1 to 2 inches into the soil, and smooth the surface.
Lay strips of sod beginning at the lowest area to be sodded and perpendicular to the direction of water flow. Wedge strips securely into place. Square the ends of each strip to provide for a close, tight fit. Stagger joints at least 12 inches. Staple on slopes steeper than 3H:1V. Staple the upstream edge of each sod strip.
Roll the sodded area and irrigate.
When sodding is carried out in alternating strips or other patterns, seed the areas between the sod immediately after sodding.
If the grass is unhealthy, the cause shall be determined and appropriate action taken to reestablish a healthy groundcover. If it is impossible to establish a healthy groundcover due to frequent saturation, instability, or some other cause, the sod shall be removed, the area seeded with an appropriate mix, and protected with a net or blanket.