http://ladbs.org/LADBSWeb/LADBS_Forms/PlanCheck/PC-GRAD.Corr11-GradingPlanCheck.pdf
The link above is to Los Angeles City's standard grading plan check list.
Item G. 2 (on page 5 of 6) states "Provide retaining wall details on plans, show: surface drains, subsurface drains, slope of backfill...