Drainage swales, also referred to as "bench drains" or "V-ditches".
Swales tend to become filled with leaves, overgrown vegetation, and debris over the course of the year. If you have a drainage swale on your property, it's your responsibility to maintain it so that it functions properly. Improperly maintained drainage swales interferes with proper drainage flows that can result in property damage caused by slope failure, erosion, or excess storm-water runoff. In past years, the City found that many of the slope erosion problems on private property were caused by unmaintained drainage swales that overflowed resulting in the slope failing. This can be avoided with proper maintenance.
(RPVMC § 17.56.060)
As an additional reminder, the City's Municipal Code does not permit the construction of any structure within or above a drainage swale, or on a slope on or equal to 35% or greater. This includes decks, stairs, or structures of any kind. Please keep this in mind if you're planning a project near or on a slope.