Stanley A. Mahr Reservoir dam
Stanley A. Mahr Reservoir
Stanley A. Mahr Reservoir, located in Olivenhain, California, is a crucial water supply infrastructure managed by a public utility. With a height of 79 feet and a capacity of 166 acre-feet, this earth dam was completed in 1981 to serve multiple purposes including flood risk reduction, irrigation, and water supply. The reservoir is situated on the Tr Encinitas Creek, covering a surface area of 8 acres with a drainage area of 0.04 square miles.
The dam's high hazard potential is closely monitored by the California Department of Water Resources (DWR) under the Safety of Dams program. Despite the satisfactory condition assessment in 2017, regular inspections are conducted to ensure its structural integrity and safety. In the event of emergencies, an Emergency Action Plan (EAP) is in place, last revised in February 2019, to guide response and coordination efforts. With its strategic location and vital role in water resource management, Stanley A. Mahr Reservoir stands as a critical asset in maintaining water security and resilience in San Diego County.
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 Stanley A. Mahr Reservoir -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| San Luis Rey R A Oceanside Ca | 2 cfs | → |
| Los Penasquitos C Nr Poway Ca | 3 cfs | → |
| Santa Margarita R A Ysidora Ca | · | → |
| Guejito C Nr San Pasqual Ca | 0 cfs | → |
| Santa Maria C Nr Ramona Ca | · | → |
| Oneill Lake Outlet Ch Nr Fallbrook Ca | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Stanley A. Mahr Reservoir.
Boat launches
- Lake Hodges Boat Launching Area
- Lake Miramar
- Shore Drive San Diego
- Mission Bay Drive San Diego
- Santa Clara Place 1001, San Diego
Campgrounds
- South Carlsbad State Beach
- San Elijo State Beach
- Group Camp Site
- Guajome Park
- Dixon Lake
- Oceanside Harbor
Fishing spots
Paddle runs
- Santa Margarita River
- Devil Canyon Tributary To San Mateo Creek
- Confluence Of Fry And Iron Spring Creeks (E1/2, Sec 3, T10s,R1e To Se1/4 Sec 16, T10s, R2e
- Forest Boundary, Above Zoo Creek Below Spillway (S1/2, Sec 3, T11s, R2e) To La Jolla Indian Reservation Boundary (N1/2, Sec 31, T10s, R2e)
- San Mateo Wilderness Boundary To Nf Boundary With Camp Pendleton
Track Stanley A. Mahr Reservoir 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 Stanley A. Mahr Reservoir
Where does the data for Stanley A. Mahr 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 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 Stanley A. Mahr Reservoir.