Morgan Debris Basin

Morgan Debris Basin is an earth dam located in Los Angeles County, California, built in 1962. It carries a High hazard potential classification and has a satisfactory condition assessment.

Hazard potentialHighFailure would probably cost lives
ConditionSatisfactoryBest of 4 ratings
Emergency action planOn file
Last inspection12/02/2025
Height37 ft
Built196264 years ago

Dam profile

NID height · 37 ft
37 FT TWO-STORY HOUSEMEDIAN U.S. DAM · 24 FT

37 ft tall and 380 ft long, taller than 83% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.

About Morgan Debris Basin

The primary purpose of Morgan Debris Basin is debris control. The dam is designed to catch sediment, rocks, and debris carried by flowing water — particularly important in areas prone to mudslides or heavy erosion. The dam is owned by Los Angeles County Department of Public Works (local government). It impounds the Morgan Canyon Crk near Glendora.

The dam stands 37 feet tall and stretches 380 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 21 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1962, the structure is well into its service life at over 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 12/02/2025.

At 37 feet, this dam is taller than 83% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

Location

StateCalifornia
CountyLos Angeles
Nearest CityGlendora
River/StreamMorgan Canyon Crk
Coordinates34.14140, -117.82090

Physical Characteristics

Dam TypeEarth
NID Height37 ft
Dam Height37 ft
Dam Length380 ft
Year Completed1962 (64 years old)

Storage & Hydraulics

NID Storage21 acre-ft
Max Storage21 acre-ft
Surface Area2 acres
Drainage Area0 sq mi

Ownership & Safety

PurposeDebris Control
OwnerLos Angeles County Department of Public Works
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection12/02/2025
Emergency Action PlanYes

Identifiers

NID IDCA01385
Federal IDCA01385
More InfoState Dam Safety Program