Diamond Lake Dam (Poweshiek Co) dam
Diamond Lake Dam (Poweshiek Co)
Diamond Lake Dam in Poweshiek County, Iowa, stands as a vital structure for water supply and recreational purposes. Completed in 1952, this earth dam rises 40 feet high and stretches 900 feet in length, creating a reservoir with a capacity of 1100 acre-feet. With a normal storage of 780 acre-feet and a surface area of 93 acres, the dam plays a crucial role in managing water resources in the region.
Located on TR-Moon Creek in the city of Spring Valley, Diamond Lake Dam is regulated by the Iowa Department of Natural Resources (DNR) and undergoes regular inspections to ensure its structural integrity. With a significant hazard potential and a satisfactory condition assessment, the dam has a moderate risk rating. Despite its uncontrolled spillway type with a width of 5 feet, the dam continues to serve its primary purpose of providing water supply while offering recreational opportunities for the local community.
Maintaining a close watch on the dam's condition, authorities conduct inspections every five years to assess any potential risks and implement necessary risk management measures. With a history dating back to the mid-20th century, Diamond Lake Dam remains a key infrastructure supporting water resources and climate resilience efforts in Poweshiek County, Iowa.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Diamond Lake Dam (Poweshiek Co) -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| South Skunk River Near Oskaloosa | 1,230 cfs | → |
| Walnut Creek Near Hartwick | 33 cfs | → |
| Richland Creek Near Haven | 34 cfs | → |
| Big Bear Creek At Ladora | 122 cfs | → |
| Iowa River Near Belle Plaine | 2,050 cfs | → |
| Des Moines River Near Tracy | 6,910 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Diamond Lake Dam (Poweshiek Co).
Boat launches
- Jade Street Jasper County
- Rock Creek East Street Jasper County
- 216th Street Iowa County
- Mahaska County
- State Highway 21 Iowa County
- 360th Street Tama County
Track Diamond Lake Dam (Poweshiek Co) in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Diamond Lake Dam (Poweshiek Co)
Where does the data for Diamond Lake Dam (Poweshiek Co) come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Significant hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Diamond Lake Dam (Poweshiek Co).