Changes

*Typical dimensions for the trench excavation are 300 mm deep and 600 mm wide. The trench may be any length,  

*Typical dimensions for the trench excavation are 300 mm deep and 600 mm wide. The trench may be any length,  

*The trench should be lined with geotextile before filling with gravel,   

*The trench should be lined with geotextile before filling with gravel,   

*River rock or decorative aggregate may be included in a layer at the top of the gravel fill, for aesthetic value.  

*River rock or decorative [[stone]] may be included in a layer at the top of the gravel fill, for aesthetic value.

==Materials==

==Materials==