Holly Hills Section 4 Swm Pond 1 is an earth dam located in Frederick County, Maryland, built in 2001. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 26 ft26 ft tall and 500 ft long, taller than 55% 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 Holly Hills Section 4 Swm Pond 1
The primary purpose of Holly Hills Section 4 Swm Pond 1 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 Holly Hills HOA (private). It impounds the Long Branch near Ijamsville Rd.
The dam stands 26 feet tall and stretches 500 feet across, has a maximum storage capacity of 73 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 2001, the structure is relatively new.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 01/29/2024.
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Location
| State | Maryland |
| County | Frederick |
| Nearest City | Ijamsville Rd |
| River/Stream | Long Branch |
| Coordinates | 39.38972, -77.32472 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 500 ft |
| Year Completed | 2001 (25 years old) |
Storage & Hydraulics
| NID Storage | 73 acre-ft |
| Max Storage | 73 acre-ft |
| Drainage Area | 0 sq mi |
| Max Discharge | 4,500 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Holly Hills HOA |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 01/29/2024 |
| Emergency Action Plan | No |
Identifiers
| NID ID | MD00375 |
| Federal ID | MD00375 |
| More Info | State Dam Safety Program |