Lake Williams
Lake Williams is an earth dam located in York County, Pennsylvania, built in 1912. It carries a High hazard potential classification and has a poor condition assessment.
About Lake Williams
The primary purpose of Lake Williams 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 York Water Company (private). It impounds the East Branch Codorus Creek.
The dam stands 58 feet tall and stretches 700 feet across, creates a reservoir covering 165 acres, has a maximum storage capacity of 5,800 acre-feet, and collects water from a drainage area of 45 square miles. Completed in 1912, the structure is over a century 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 03/08/2021.
At 58 feet, this dam is taller than 95% 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 Pennsylvania 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 | Pennsylvania |
| County | York |
| River/Stream | East Branch Codorus Creek |
| Coordinates | 39.89056, -76.72972 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 58 ft |
| Dam Height | 58 ft |
| Dam Length | 700 ft |
| Year Completed | 1912 (114 years old) |
Storage & Hydraulics
| NID Storage | 5,800 acre-ft |
| Max Storage | 5,800 acre-ft |
| Normal Storage | 3,370 acre-ft |
| Surface Area | 165 acres |
| Drainage Area | 45 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | YORK WATER COMPANY |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 03/08/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA00338 |
| Federal ID | PA00338 |
| More Info | State Dam Safety Program |