Lay person's definitions of flood-related terms
Bench Drain - Typically a gunite or concrete V-ditch located horizontally and vertically along residential hillside areas. This device assists in draining the slope to protect against hillside erosion. Typical width is 3 to 5 feet and typical depth is 12". (Same as a Slope Drain)
Debris - Any combination of soil, rock, mud, trees, or vegetation usually transported by debris flow.
Debris Flows - Consist of any soil, rocks, boulders, trees, or brush being moved by stormwaters and
containing sufficient strength to destroy or move objects such as cars and buildings in their path.
Drainage Patterns - The drainage paths stormwater runoff usually or historically takes through a given
Engineered Concrete Block Walls - Walls engineered to withstand loads caused by water and debris.
These walls are considered to be permanent, and do not require yearly replacement.
Flood - (1) A general and temporary condition of partial or complete inundation of normally dry-land
areas from the overflow of inland or tidal waters; or (2) the unusual and rapid accumulation or runoff of
surface waters from any source.
Flood Insurance - Insurance to cover damages to your home, or belongings in your home, caused by
flooding, that can be purchased through your local insurance agent.
Ground Cover - Typically a low-lying plant that will spread outward, eventually covering all surrounding
Gullying - Formation of ditches or hollows worn by running water.
Natural Watercourse - An unimproved natural stream of any size. Includes rivers, creeks, branches,
canyons, arroyos, gullies, washes, etc.
Ornamentals - Plants or shrubs grown for their decorative effect.
Overgrowth - Foliage that has grown and spread out so as to obstruct or block any natural
watercourse, improved drainage device, or structure.
Rainy Season - The period of the year from October 15 to April 15 when County of Los Angeles usually
receives its largest amount of rain.
Riprap - A layer of large stones or boulders placed together without order, usually used for erosion
protection along streams or shore lines.
Sandbags - A burlap or plastic bag that can be filled with sand or native soil, which can be stacked or
placed to redirect storm and debris flows away from homes or property improvements.
Slope Drain - Typically a gunite or concrete V-ditch located horizontally and vertically along residential
hillside areas. This device assists in draining the slope to protect against hillside erosion. Typical width
is 3 to 5 feet and typical depth is 12". (Same as a Bench Drain)
Sump - A low-lying area with no drainage outlet.
Sump Pump - A pump designed to pump water out of a sump or basement.