Gross
Key Takeaway
Gross is classified as high hazard in Colorado. It was completed in 1955 and is 71 years old. Its primary use is hydroelectric. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.
Physical Details
| Dam Height | 340 ft (taller than 99.8% in CO) |
| Dam Length | 1,050 ft |
| Dam Type | Concrete |
| Max Storage | 46.2K acre-ft |
| Normal Storage | 41.0K acre-ft |
| Surface Area | 413 acres |
| Drainage Area | 93 sq mi |
| Max Discharge | 10,000 cfs |
| Year Completed | 1955 (71 years old) |
| NID ID | CO00247 |
Safety Information
Loss of human life is likely if the dam fails.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Denver Water
Local Government
Nearby Dams
Kossler
Boulder, CO
High Hazard 20 ftSouth Boulder Diversion Intake Dam
Boulder, CO
Low Hazard 34 ftPine Brook
Boulder, CO
High Hazard 84 ftViele Lake
Boulder, CO
Low Hazard 19 ftMesa Park
Boulder, CO
High Hazard 23 ftBarker Meadow
Boulder, CO
High Hazard 177 ftLake Manchester
Gilpin, CO
Low Hazard 19 ftBraecher Ranch
Gilpin, CO
Low Hazard 21 ftFrequently Asked Questions
What is the hazard classification of Gross?
Gross is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Gross?
Gross is owned by Denver Water (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Gross built?
Gross was completed in 1955, making it 71 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of Gross?
Gross serves the following purposes: Hydroelectric, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Gross?
Gross has a dam height of 340 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was Gross last inspected?
Gross was last inspected on September 27, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.