Youngs Lake New Inlet Dam
Youngs Lake New Inlet Dam is an earth dam located in King County, Washington, built in 1926. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Youngs Lake New Inlet Dam
The primary purpose of Youngs Lake New Inlet Dam 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 Seattle Public Utilities (public utility). It impounds the Tr-cedar River near Topographic Depression.
The dam stands 20 feet tall and stretches 400 feet across, creates a reservoir covering 690 acres, has a maximum storage capacity of 35,450 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1926, the structure is well-established, with more than 75 years of service.
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 06/02/2024.
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 Washington 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 | Washington |
| County | King |
| Nearest City | Topographic Depression |
| River/Stream | Tr-cedar River |
| Coordinates | 47.42092, -122.10290 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 20 ft |
| Dam Length | 400 ft |
| Year Completed | 1926 (100 years old) |
Storage & Hydraulics
| NID Storage | 35,450 acre-ft |
| Max Storage | 35,450 acre-ft |
| Normal Storage | 33,760 acre-ft |
| Surface Area | 690 acres |
| Drainage Area | 2 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Seattle Public Utilities |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/02/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00415 |
| Federal ID | WA00415 |
| More Info | State Dam Safety Program |