Blue Marsh Dam
Blue Marsh Dam is a rockfill dam located in Berks County, Pennsylvania, built in 1977. It carries a High hazard potential classification.
About Blue Marsh Dam
The primary purpose of Blue Marsh Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Usace - Philadelphia District (federal). It impounds the Tulpehocken Creek near Reading.
The dam stands 100 feet tall and stretches 1,775 feet across, creates a reservoir covering 1,147 acres, has a maximum storage capacity of 129,900 acre-feet, and collects water from a drainage area of 175 square miles. Completed in 1977, the structure is 49 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. An emergency action plan is in place for this dam. The most recent inspection on record was 06/10/2024.
At 100 feet, this dam is taller than 98% 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 | Berks |
| Nearest City | Reading |
| River/Stream | Tulpehocken Creek |
| Coordinates | 40.37903, -76.03143 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 100 ft |
| Dam Length | 1,775 ft |
| Year Completed | 1977 (49 years old) |
Storage & Hydraulics
| NID Storage | 129,900 acre-ft |
| Max Storage | 129,900 acre-ft |
| Normal Storage | 22,897 acre-ft |
| Surface Area | 1,147 acres |
| Drainage Area | 175 sq mi |
| Max Discharge | 70,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Philadelphia District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 06/10/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA00921 |
| Federal ID | PA00921 |
| More Info | State Dam Safety Program |