Whittier Reservoir No. 4 dam
Whittier Reservoir No. 4
Whittier Reservoir No. 4, located in Whittier, California, is a vital water supply infrastructure owned by the local government. With a dam height of 55 feet and a hydraulic height of 53 feet, this Earth type dam was completed in 1931 and has a storage capacity of 32 acre-feet. The reservoir serves the primary purpose of water supply, drawing from the Tr San Gabriel River for its source.
Despite its age, Whittier Reservoir No. 4 has been maintained in satisfactory condition, with regular inspections showing a low hazard potential. The dam is regulated by the California Department of Water Resources and adheres to state permitting, inspection, and enforcement protocols. The last inspection in March 2021 confirmed its structural integrity, ensuring the safety and reliability of its water supply function for the surrounding area.
With a surface area of 1 acre and a drainage area of 0.08 square miles, Whittier Reservoir No. 4 plays a crucial role in managing water resources in Los Angeles County. As a key component of the local water supply infrastructure, it underscores the importance of maintaining and monitoring our water resources to meet the needs of the community and mitigate the impacts of climate change on water availability.
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 Whittier Reservoir No. 4 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| San Gabriel R Ab Whittier Narrows Dam Ca | 9 cfs | → |
| Rio Hondo Bl Whittier Narrows Dam Ca | 13 cfs | → |
| Rio Hondo Ab Whittier Narrows Dam Ca | 77 cfs | → |
| San Gabriel R Bl Santa Fe Dam Nr Baldwin Pk Ca | 141 cfs | → |
| Brea C Bl Brea Dam Nr Fullerton Ca | 0 cfs | → |
| Fullerton C Bl Fullerton Dam Nr Brea Ca | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Whittier Reservoir No. 4.
Boat launches
Campgrounds
Fishing spots
Paddle runs
- Gaging Station Below Spillway Of Cogswell Dam (Ne 1/4, Se 1/4, Sec 19, T2n, R10w) To Confluence With Nf San Gabriel River (Sw 1/4.Sw 1/4, Sec 15, T2n, R9w)
- West Fork - Headwaters (Se 1/4, Ne 1/4, Sec 14, T2n, R12w) To Cogswell Reservoir (Ne 1/4, Sw 1/4, Sec 24, T2n, R9w
- North Fork - Confluence Of Soldier And Coldbrook Creeks (Se1/4,Sw1/4, Sec) 5, T2n,,R9w To Conflluence With West Fork Of San Gabriel (Sw 1/4,Sw1/4, Sec 17, T2n, R8w)
- Laurel Gulch To Confluence With Mineo Canyon (Se 1/4, Sw 1/4, Sec 17, T2n, R8w)
- Cooper Canyon- Near State Highway 2 (Sw 1/4, Ne 1/4, Sec 16, T3n, R10w To Confluence With Little Rock Creek
- Mainstream - Confluence With Cooper Canyon To Confluence Wit South Fork Little Rock Creek
Track Whittier Reservoir No. 4 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 Whittier Reservoir No. 4
Where does the data for Whittier Reservoir No. 4 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 Whittier Reservoir No. 4.