Patterson dam
Patterson
Patterson is a significant earth dam located in Alameda, California, with a primary purpose of water supply. Completed in 1962, this dam stands at a height of 100 feet and has a hydraulic height of 99.83 feet, providing a storage capacity of 46 acre-feet. The dam is regulated by the California Department of Water Resources (DWR) under the Safety of Dams program, with state jurisdiction and enforcement in place to ensure its safety and proper maintenance.
Despite its fair condition assessment as of September 2017, Patterson poses a significant hazard potential due to its location and structural specifics. The dam is subject to regular inspections with a frequency of once a year, with the most recent one conducted in February 2021. The dam's emergency action plan (EAP) status, risk assessment, and management measures are currently not available, indicating a potential area for improvement in terms of emergency preparedness and response.
Owned and operated by the local government, Patterson serves as a crucial water resource in the region, contributing to water supply needs in the area. With its strategic location and design, this dam plays a vital role in managing water resources and ensuring a reliable supply for the community. Continuous monitoring and adherence to safety regulations are essential to mitigate any potential risks associated with the dam and to maintain its functionality for the benefit of the local population.
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 Patterson -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Alameda C Flood Channel A Union City Ca | 23 cfs | → |
| Alameda C Nr Fremont Ca | 25 cfs | → |
| Dry C A Union City Ca | · | → |
| Alameda C Nr Niles Ca | 17 cfs | → |
| Matadero C A Palo Alto Ca | 0 cfs | → |
| Castro Valley C A Hayward Ca | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Patterson.
Boat launches
- Chelsea Drive 5094, Newark
- San Francisco Bay Trail East Palo Alto
- Palo Alto Boat Launch
- Lake Elizabeth Boat Ramp
- Santa Clara County
- Whidbey Lane Redwood City
Campgrounds
- 1
- Anthony Chabot Family Campground
- Alameda County Fairgrounds Rv
- Sunol Regional Wilderness
- Youth Group Camp Area
- Oak Knoll Group Area
Fishing spots
Paddle runs
- Headwaters To Mouth
- Gold Creek To Three Pools (Opal Creek Run)
- Headwaters To Ends One Quarter Mile South Of Bear Valley Road Bridge Segment 1: Ends 1/4 Mile South Of Bear Valley Road Bridge Segment 2: Caltrans Corporation Yard At Point Reyes Staton.
- Olema Ranch Campground To Caltrans Corporation Yard At Point Reyes Station
More reservoirs
Track Patterson 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 Patterson
Where does the data for Patterson 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 Patterson.