Folsom - Mormon Island Auxiliary Dam dam
Folsom - Mormon Island Auxiliary Dam
The Folsom - Mormon Island Auxiliary Dam, located in Sacramento, California, is a key structure managed by the Bureau of Reclamation for flood risk reduction along the Blue Ravine river. Completed in 1955, this earth dam stands at a height of 110 feet and has a storage capacity of 1,120,000 acre-feet to protect the surrounding area from potential flooding events. Despite its high hazard potential, the dam has not been assessed for its current condition, highlighting the importance of regular inspections and maintenance to ensure its continued safety and effectiveness.
In addition to flood risk reduction, the Folsom - Mormon Island Auxiliary Dam serves multiple purposes such as hydroelectric power generation, irrigation, recreation, and water supply for the region. Its association with 11 other structures further emphasizes its critical role in managing water resources and supporting various activities in the area. The dam's location in Folsom, under the jurisdiction of the San Francisco District of the US Army Corps of Engineers, underscores its significance in the local water infrastructure and climate resilience efforts.
While the Folsom - Mormon Island Auxiliary Dam does not have a spillway, its design and construction by the Bureau of Reclamation demonstrate a commitment to effective water management and flood protection. With a high-risk assessment rating and limited information on its current condition, continued monitoring and risk management measures are essential to ensure the safety and reliability of this vital infrastructure in the face of evolving climate challenges.
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 Folsom - Mormon Island Auxiliary Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| American R A Fair Oaks Ca | 1,990 cfs | → |
| Deer C Nr Cameron Park Ca | 8 cfs | → |
| Dry C A Vernon St Bridge A Roseville Ca | 159 cfs | → |
| Cosumnes R A Michigan Bar Ca | 227 cfs | → |
| Arcade C Nr Del Paso Heights Ca | · | → |
| Nf American R A North Fork Dam Ca | 463 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Folsom - Mormon Island Auxiliary Dam.
Boat launches
- Green Valley Road 661, El Dorado Hills
- Park Road, Granite Bay
- Lake Natoma Northern Boat Ramp
- Oaks Nature Trail El Dorado County
- Oak Hill Road 7935, Pilot Hill
- Willow Creek Boat Ramp
Fishing spots
Track Folsom - Mormon Island Auxiliary 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 Folsom - Mormon Island Auxiliary Dam
Where does the data for Folsom - Mormon Island Auxiliary 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 High 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 Folsom - Mormon Island Auxiliary Dam.