Lower Van Norman Bypass dam
Lower Van Norman Bypass
The Lower Van Norman Bypass is a key water infrastructure located in Granada Hills, California, designed primarily for hydroelectric power generation and water supply purposes. Completed in 1970, this earth dam stands at a height of 78 feet and has a hydraulic height of 69.3 feet, with a storage capacity of 240 acre-feet. Situated offstream, this structure serves to manage water resources in the region, with a drainage area of 0.03 square miles and a surface area of 12 acres.
Owned and regulated by the local government, the Lower Van Norman Bypass is under the oversight of the California Department of Water Resources (DWR) and the Safety of Dams agency. With a low hazard potential and satisfactory condition assessment as of September 2017, this dam plays a critical role in the water management system of Los Angeles County. Its last inspection in November 2020 revealed no significant issues, indicating a well-maintained and functional structure.
For enthusiasts interested in water resources and climate, the Lower Van Norman Bypass represents a vital piece of infrastructure contributing to the sustainable use of water in the region. With its dual purpose of hydroelectric power generation and water supply, this earth dam serves as a testament to California's commitment to efficient water management and renewable energy production. As it continues to play a crucial role in the local water infrastructure, ensuring its ongoing maintenance and regulatory compliance remains essential for the community's water security and environmental resilience.
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 Lower Van Norman Bypass -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Big Tujunga C Bl Hansen Dam Ca | · | → |
| Los Angeles R A Sepulveda Dam Ca | 74 cfs | → |
| Santa Clara R Nr Piru Ca | 79 cfs | → |
| Arroyo Seco Nr Pasadena Ca | 6 cfs | → |
| Piru Creek Below Santa Felicia Dam Ca | 101 cfs | → |
| Piru Creek Above Lake Piru Ca | 34 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lower Van Norman Bypass.
Boat launches
- Lake Hughes Road Castaic
- Piru Canyon Road 4780, Castaic
- Interstate 5, Lebec
- Vacquero Boating And Picnic Site
- Vista Del Lago Road 21, Lebec
Campgrounds
- Group Campground 6
- Group Campground 5
- Group Campground 4
- Group Campground 3
- Group Campground 2
- Group Campground 1
Fishing spots
Paddle runs
- Site Of St Francis Dam Disaster To Seco Canyon At The Nf Boundary
- 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
- Lower Piru Creek (Oulet At Pyramid Reservoir) To Piru Reservoir
- Green Valley At The Nf Boundary To Site Of St Francis Dam Disaster
- Headwaters In The Santa Monica Mountains To Mouth At Pacific Ocean
- 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)
Track Lower Van Norman Bypass 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 Lower Van Norman Bypass
Where does the data for Lower Van Norman Bypass 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 Lower Van Norman Bypass.