Retaining wall permits are issued a fence permit number and a fence permit application is required to be filled out.
Fence Permit
Cost:  $50.00
 
If any portion of the retaining wall reaches, or exceeds, four (4) feet in height a fence permit is required. 
 
In order to obtain a permit, we request that you bring a copy of your property survey (typically a legal size sheet of paper that shows the shape of your lot, the shape of your house on the lot, any accessory buildings that were in existence when the survey was done, and distances to property lines marked from the house and accessory structures; additionally, it will have the legal description of the home) which should be in with your closing documents; however, if you do not have a copy of the survey, we ask that you draw, to scale (1" = 20') the shape of your lot, the shape of your house on the lot, any accessory buildings that are in existence, and distances to property lines marked from the house and accessory structures.  Please mark on either paper (survey or hand drawn) where you are installing / replacing / repairing the retaining wall.
 
Additionally, you must provide either an engineers report on the retaining walls structure; or, adhere to the City of Garland Engineering Departments Retaining Wall Specifications
(http://www.ci.garland.tx.us/Home/Departments/Development+Services/Engineering/SS91A1.htm)