Decoto Reservoir dam
Decoto Reservoir
Decoto Reservoir, located in Fremont, California, is a vital offstream water supply structure primarily owned by the local government. Completed in 1966, this Earth type dam stands at a height of 33 feet, with a hydraulic height of 30.5 feet and a length of 1360 feet. It has a storage capacity of 46 acre-feet, serving the purposes of irrigation and water supply for the region.
Despite its satisfactory condition assessment as of September 2017, Decoto Reservoir is classified as having a high hazard potential. Regular inspections are conducted, with the last one taking place in February 2021. The dam is regulated, permitted, and inspected by the California Department of Water Resources' Safety of Dams program, ensuring its compliance with state safety standards. In the event of an emergency, the reservoir's Emergency Action Plan is expected to be readily available, although details on its preparation and adherence to guidelines are currently unspecified.
For water resource and climate enthusiasts, Decoto Reservoir offers a fascinating case study in water management and infrastructure. With its location in Alameda County, the reservoir plays a crucial role in supporting local agricultural activities and providing a reliable water supply to the surrounding communities. As efforts continue to maintain its structural integrity and emergency preparedness, Decoto Reservoir stands as a testament to the ongoing importance of sustainable water resource management in the face of changing climate conditions.
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 Decoto Reservoir -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Alameda C Nr Fremont Ca | 11 cfs | → |
| Dry C A Union City Ca | · | → |
| Alameda C Nr Niles Ca | 14 cfs | → |
| Alameda C Flood Channel A Union City Ca | 8 cfs | → |
| Arroyo De La Laguna A Verona Ca | 12 cfs | → |
| San Lorenzo C A Hayward Ca | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Decoto Reservoir.
Boat launches
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Campgrounds
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Fishing spots
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River runs
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About Decoto Reservoir
Where does the data for Decoto Reservoir 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 below 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.
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.