Maerkle
Maerkle is an earth dam located in San Diego County, California, built in 1963. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Maerkle
The primary purpose of Maerkle is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Carlsbad Municipal Water District (public utility). It impounds the Tr Aqua Hedionda near Carlsbad.
The dam stands 165 feet tall and stretches 800 feet across, creates a reservoir covering 14 acres, has a maximum storage capacity of 600 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1963, 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 04/23/2025.
At 165 feet, this dam is taller than 99% of all dams in the United States.
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
| State | California |
| County | San Diego |
| Nearest City | Carlsbad |
| River/Stream | Tr Aqua Hedionda |
| Coordinates | 33.15210, -117.25990 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 165 ft |
| Dam Height | 165 ft |
| Dam Length | 800 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 600 acre-ft |
| Max Storage | 600 acre-ft |
| Surface Area | 14 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Carlsbad Municipal Water District |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/23/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00844 |
| Federal ID | CA00844 |
| More Info | State Dam Safety Program |