Portal Forebay Dike dam
Portal Forebay Dike
Located in Fresno, California, the Portal Forebay Dike is a private dam with a primary purpose of hydroelectric power generation. Built in 1956, this earth dam stands at a height of 18 feet and has a length of 350 feet. It has a storage capacity of 390 acre-feet, with a normal storage level of 325 acre-feet. Situated on Camp 61 Creek in the city of Mono Hot Springs, this structure is regulated by the state and inspected by the Department of Water Resources (DWR) under the Safety of Dams program.
The Portal Forebay Dike is owned by a private entity and is under the jurisdiction of the state of California. As a vital component of the local water resource infrastructure, it plays a crucial role in water management and hydroelectric power generation in the region. The dam's low hazard potential and high risk assessment rating highlight the importance of regular inspections and maintenance to ensure its structural integrity and safety. The Federal Energy Regulatory Commission oversees its regulation and inspections, emphasizing the commitment to maintaining its operational efficiency and safety standards.
Despite its low hazard potential, the Portal Forebay Dike serves as a significant structure for water storage and power generation in the area. With a focus on maintaining its safety and structural integrity, the dam plays a crucial role in supporting the region's water and energy needs. As water resource and climate enthusiasts continue to monitor and assess the impact of infrastructure like the Portal Forebay Dike on the local ecosystem and climate resilience, ongoing regulatory oversight and risk management measures are essential to ensure the long-term sustainability of this vital infrastructure.
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 Portal Forebay Dike -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mf San Joaquin R Nr Mammoth Lakes Ca | 278 cfs | → |
| Hot C A Flume Nr Mammoth Lakes Ca | 64 cfs | → |
| Nf Willow C Nr Sugar Pine Ca | 416 cfs | → |
| Deadman C A Big Springs Nr Crestview Ca | 33 cfs | → |
| Big C Div Nr Fish Camp Ca | 0 cfs | → |
| Merced R A Happy Isles Bridge Nr Yosemite Ca | 725 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Portal Forebay Dike .
Boat launches
- Lake Edison Boating Site
- Florence Lake Boating Site
- Florence Lake Campground
- Huntington Boat Ramp & Launching Site
- Mammoth Pool Rd, California
- Redinger Boating Site
Campgrounds
- Portal Forebay Campground
- Portal Forebay
- Bolsillo Campground
- Mono Hot Springs
- Mono Hot Springs Campground
- Badger Flat Group Campground
Fishing spots
Paddle runs
- Blarney Meadows To South End Of Florence Lake
- Hot Springs Area To West End Of Blarney River
- Confluence With North Fork San Joaquin River To Hells Half Acre
- Northwest Boundary Of Nf/Kings Canyon Np To Hot Springs Area
- Rainbow Falls To Confluence With North Fork San Joaquin River
- Cora Creek To Confluence With San Joaquin River
Track Portal Forebay Dike 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 Portal Forebay Dike
Where does the data for Portal Forebay Dike 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 Portal Forebay Dike .