Upper 4s Ranch dam
Upper 4s Ranch
Upper 4s Ranch, located in Del Mar, California, is a privately owned dam on Lusardi Creek with a primary purpose of water supply for irrigation. Built in 1927, this arch-type dam stands at 28 feet high and has a storage capacity of 48.3 acre-feet. With a low hazard potential and satisfactory condition assessment, Upper 4s Ranch plays a crucial role in water resource management in the region.
Managed by the California Department of Water Resources (DWR) and subject to state regulations, inspections, and enforcement, Upper 4s Ranch is a key infrastructure for maintaining water supply and ensuring the safety of dams in the area. The dam's last inspection in June 2020 confirmed its sound structural integrity, further reinforcing its importance in the local water management system.
With its historical significance dating back almost a century and its ongoing role in supporting irrigation and water supply needs, Upper 4s Ranch serves as a vital resource for the community. As water resource and climate enthusiasts, understanding the infrastructure and management of dams like Upper 4s Ranch is essential for sustainable water management practices in California.
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 Upper 4s Ranch -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Los Penasquitos C Nr Poway Ca | 3 cfs | → |
| Santa Maria C Nr Ramona Ca | · | → |
| Guejito C Nr San Pasqual Ca | 0 cfs | → |
| San Diego R A Mast Rd Nr Santee Ca | 7 cfs | → |
| Santa Ysabel C Nr Ramona Ca | 0 cfs | → |
| Los Coches C Nr Lakeside Ca | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Upper 4s Ranch.
Boat launches
- Lake Hodges Boat Launching Area
- Lake Miramar
- Mission Bay Drive San Diego
- Shore Drive San Diego
- Santa Clara Place 1001, San Diego
Campgrounds
- Dos Picos
- San Elijo State Beach
- Group Camp Site
- Dixon Lake
- Santee Lakes Regional Park
- Admiral Baker Military - San Diego Ns
Fishing spots
Paddle runs
- 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)
- Confluence Of Fry And Iron Spring Creeks (E1/2, Sec 3, T10s,R1e To Se1/4 Sec 16, T10s, R2e
- Santa Margarita River
- Devil Canyon Tributary To San Mateo Creek
- Crouch Ranch To Morena Reservoir
Track Upper 4s Ranch 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 Upper 4s Ranch
Where does the data for Upper 4s Ranch 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 Upper 4s Ranch.