Johnston Dam, located in Lynnville, Iowa, is a private dam designed by NRCS with a height of 30 feet and a length of 527 feet.
Wind
Humidity
Completed in 2005, the dam serves multiple purposes including fire protection and creating a small fish pond. With a storage capacity of 193 acre-feet, the dam regulates the flow of Turner Creek and covers a surface area of 10.9 acres.
Managed by the Iowa DNR, Johnston Dam is state-regulated with inspection, permitting, and enforcement protocols in place. The dam has a significant hazard potential but is currently rated as "Not Rated" in terms of condition assessment. While the risk assessment is moderate, with a score of 3, there are no specific risk management measures or emergency action plans in place as of the last data update in April 2021.
Johnston Dam plays a vital role in water resource management in Jasper County, Iowa, contributing to fire protection and supporting local wildlife. As a private structure with state oversight, the dam underscores the importance of sustainable infrastructure to ensure the safety and well-being of the community and surrounding environment in the face of climate variability and water resource challenges.
Year Completed |
2005 |
Dam Length |
527 |
Dam Height |
30 |
River Or Stream |
TR-TURNER CREEK |
Primary Dam Type |
Earth |
Surface Area |
10.9 |
Drainage Area |
0.25 |
Nid Storage |
193 |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
30 |
Timber Creek Near Marshalltown
|
37cfs |
Richland Creek Near Haven
|
12cfs |
South Skunk River At Colfax
|
211cfs |
Walnut Creek Near Hartwick
|
13cfs |
Des Moines River Near Pella
|
1220cfs |
South Skunk River Near Oskaloosa
|
485cfs |
| Location | Reservations | Toilets |
|---|---|---|
Rock Creek State Park
|
||
Kellogg RV Park
|
||
Mariposa Co Park
|