Cottonwood-green Valley Subws 75+70 #2 is an earth dam located in Monona County, Iowa, built in 1966. It carries a Low hazard potential classification.
Dam profile
NID height · 26 ft26 ft tall and 518 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 Cottonwood-green Valley Subws 75+70 #2
The primary purpose of Cottonwood-green Valley Subws 75+70 #2 is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by Monona County Swcd (local government). It impounds the Tr-little Sioux River near Castana.
The dam stands 26 feet tall and stretches 518 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 50 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1966, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.
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Location
| State | Iowa |
| County | Monona |
| Nearest City | Castana |
| River/Stream | Tr-little Sioux River |
| Coordinates | 42.06610, -95.88070 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 518 ft |
| Year Completed | 1966 (60 years old) |
Storage & Hydraulics
| NID Storage | 50 acre-ft |
| Max Storage | 50 acre-ft |
| Normal Storage | 18 acre-ft |
| Surface Area | 2 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Monona County Swcd |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA00744 |
| Federal ID | IA00744 |
| More Info | State Dam Safety Program |