Pilarcitos dam
Pilarcitos
Pilarcitos, also known as Pilarcitos Lake, is a vital water resource located in Half Moon Bay, California. Owned by the local government, this dam on Pilarcitos Creek was completed in 1866 and serves the primary purpose of water supply. With a height of 103 feet and a hydraulic height of 95.8 feet, Pilarcitos Dam has a storage capacity of 3100 acre-feet and covers a surface area of 109 acres.
Managed by the Department of Water Resources and regulated by the Safety of Dams agency, Pilarcitos Dam is considered to have a high hazard potential but is currently rated as being in satisfactory condition. The last inspection in December 2020 confirmed its structural integrity, and regular inspections are conducted to ensure the safety of the surrounding community. While the dam meets state permitting and enforcement standards, there is no information available on emergency action plans or risk assessment measures for this crucial water source.
Water resource and climate enthusiasts will be intrigued by the historical significance and technical specifications of Pilarcitos Dam. Its location in San Mateo County, California, and its association with Pilarcitos Creek make it a key component of the region's water infrastructure. As a critical water supply source, the dam's condition and regulatory oversight are essential factors in ensuring reliable water access for the surrounding area. Further exploration into the emergency preparedness and risk management aspects of Pilarcitos Dam could provide valuable insights into water resource resilience in the face of 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 Pilarcitos -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Pilarcitos C Bl Stone Dam Nr Hillsborough Ca | 4 cfs | → |
| San Mateo C Bl Lo Crystal Sp Res Nr San Mateo Ca | 4 cfs | → |
| Pilarcitos C A Half Moon Bay Ca | 10 cfs | → |
| San Francisquito C A Stanford University Ca | 6 cfs | → |
| San Gregorio C A San Gregorio Ca | 14 cfs | → |
| Matadero C A Palo Alto Ca | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Pilarcitos.
Boat launches
- San Andreas Trail San Bruno
- Sawyer Camp Trail San Mateo County
- J Hart Clinton Drive San Mateo
- San Francisco Bay Trail, South San Francisco
- Whidbey Lane Redwood City
- Harding Road San Francisco
Campgrounds
- Dispersed Camping
- Sweetwood Group Camp
- Half Moon Bay State Beach
- Candlestick Rv Park
- Rob Hill Campground
- Aquatic Park Cove
Fishing spots
Paddle runs
- Headwaters To Mouth
- 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
- Gold Creek To Three Pools (Opal Creek Run)
More reservoirs
Track Pilarcitos 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 Pilarcitos
Where does the data for Pilarcitos 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 Pilarcitos.