Porter Moss Agate Dam dam
Porter Moss Agate Dam
Porter Moss Agate Dam, located in Fall River, South Dakota, serves as a crucial water resource structure regulating a tributary of the Cheyenne River. Built in 1940, this earth dam stands at 18 feet in height and spans 550 feet in length, with a storage capacity of 144 acre-feet. Despite its low hazard potential, the dam remains state-regulated and regularly inspected by the South Dakota Department of Environment and Natural Resources to ensure its structural integrity and safety.
The dam's primary purpose and associated structures are unspecified, reflecting its private ownership and limited federal involvement. However, its location within the Omaha District and its designation as a state-regulated dam highlight its importance in water resource management. Although its condition assessment is currently "Not Rated," Porter Moss Agate Dam's historical significance and strategic position within the local watershed make it a focal point for water resource and climate enthusiasts interested in sustainable water management practices.
With Dusty Johnson (R) representing the area in Congress, issues related to water infrastructure and climate resilience are likely to be on the agenda, positioning Porter Moss Agate Dam as a key asset in the region's water resource strategy. As the dam's risk assessment and emergency preparedness measures continue to evolve, stakeholders and enthusiasts alike can monitor its progress in safeguarding the surrounding communities and ecosystem from potential water-related hazards.
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 Porter Moss Agate Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cheyenne R At Edgemont Sd | 3 cfs | → |
| Cheyenne River Near Spencer | 2 cfs | → |
| Hat Cr Near Edgemont Sd | 0 cfs | → |
| Fall R At Hot Springs Sd | 35 cfs | → |
| Cheyenne R Below Angostura Dam Sd | 1 cfs | → |
| Beaver Creek Near Pringle | 5 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Porter Moss Agate Dam.
Boat launches
- South Boat Ramp Road Fall River County
- County Highway 6d Fall River County
- Sheps Canyon Road Fall River County
- Fall River County
Campgrounds
- Cottonwood Springs
- Angostura State Rec Area
- Rifle Pit
- Elk Mountain - Wind Cave National Park
- Elk Mountain Campground
- Comanche Park Campground
Track Porter Moss Agate Dam 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 Porter Moss Agate Dam
Where does the data for Porter Moss Agate Dam 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 Low 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 Porter Moss Agate Dam.