Clearwell Phase 2 dam
Clearwell Phase 2
Clearwell Phase 2 is a public utility infrastructure located in Martinez, California, along Grayson Creek. This Earth-type dam stands at a height of 30 feet and was completed in 1977 with a storage capacity of 100 acre-feet. Designed primarily for water supply purposes, it also serves to reduce flood risks in the area. The dam has a low hazard potential and is deemed to be in satisfactory condition as of the last assessment in September 2017.
Managed by the California Department of Water Resources and regulated under the Safety of Dams program, Clearwell Phase 2 undergoes regular inspections with a frequency of once every year. The dam's location in Contra Costa County, under the jurisdiction of both the state and federal agencies, ensures that it meets all permitting, inspection, and enforcement requirements. With its proximity to the city of Martinez and oversight by Representative Mark DeSaulnier, the dam plays a crucial role in maintaining water resources and mitigating potential risks in the region.
Despite its modest size and capacity, Clearwell Phase 2's strategic placement and operational efficiency make it a vital component of the local water supply infrastructure. As climate change continues to impact water resources and weather patterns, the proper maintenance and regulation of dams like Clearwell Phase 2 are essential for ensuring water security and resilience against natural disasters in the future.
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 Clearwell Phase 2 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| San Ramon C A San Ramon Ca | 0 cfs | → |
| Cull C Ab Cull C Res Nr Castro Valley Ca | 0 cfs | → |
| Crow C Nr Hayward Ca | 0 cfs | → |
| San Joaquin R A Jersey Point Ca | 845 cfs | → |
| Marsh C A Brentwood Ca | 0 cfs | → |
| San Lorenzo C Ab Don Castro Res Nr Castro V Ca | 0 cfs | → |
About Clearwell Phase 2
Where does the data for Clearwell Phase 2 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 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.