Is key word temporary or fix?
Temporary mesures can be a mass of 12" to 24" rock on a fabric in front of wall, then fill any voids behind wall.
This is not a fix or real soltion to problem.
Fix would be to dewater and form sections that are degrated and pour concrete or demo wall and...
Stakes are utilized only for construction of mattress on slopes steeper than 2:1 and typically are placed 6' on centers. Stakes should not be relyed on for shear resistance to Hydrolic flows. This should be a function of the weight per square foot of Gabions installed.
A #6 rebar 3-4' long and...
Your most economical wall at 6' would be a gravity syatem.
It would have a 3 to 4' footprint and would cost far less than sheet pile or soil nailing. Look at Gabions or Modular Block MSE systems.
I worked for Maccaferri,Inc. for 13 years and they have developed very simple software that most anyone can use. Go to Maccaferri-usa.com and request a free issue. This software allows the use most every type of protections including grass, rock, bio-engineering. Try it.
In arid regions it will be to hard to maintain grass cover, a hard armor would be best. Animals can not grase on slope steeper than 2:1, so rock,ACB Mats or Gabion Mattress would be your best erosions protection.
