Lake Helen dam
Lake Helen
Lake Helen, located in Sonoma, California, is a privately owned reservoir primarily used for water supply purposes. Constructed in 1966, the earth dam stands at a height of 39 feet and has a storage capacity of 192 acre-feet. The reservoir covers a surface area of 14 acres and is fed by the Tr Russian River, serving as a vital resource for irrigation and recreation in the area.
Managed by the Natural Resources Conservation Service, Lake Helen has a high hazard potential but is currently in satisfactory condition as of the last assessment in September 2017. The dam is regulated by the California Department of Water Resources and undergoes regular inspections to ensure its safety and compliance with state regulations. Despite its age, Lake Helen continues to play a crucial role in providing water for agricultural and recreational activities in the region.
With its picturesque location in Graton and close proximity to the San Francisco District, Lake Helen offers a serene retreat for water resource and climate enthusiasts. The dam's emergency action plan was last revised in February 2021, ensuring that necessary measures are in place to address any potential risks. As a vital component of the local water infrastructure, Lake Helen remains a key player in sustaining the surrounding ecosystem and supporting the community's water needs.
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 Lake Helen -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Russian R Nr Guerneville Ca | 223 cfs | → |
| Mark West C Nr Mirabel Heights Ca | 25 cfs | → |
| Laguna De Santa Rosa C Nr Sebastopol Ca | 4 cfs | → |
| Russian R Nr Windsor Ca | 311 cfs | → |
| Santa Rosa C A Willowside Rd Nr Santa Rosa Ca | 10 cfs | → |
| Austin C Nr Cazadero Ca | 22 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lake Helen.
Boat launches
Campgrounds
- Campsite #13
- Campsite #20
- Campsite #22
- Campsite #21
- Bodega Dunes Campground
- Westside Regional Park Campground
Fishing spots
Paddle runs
- Olema Ranch Campground To Caltrans Corporation Yard At Point Reyes Station
- 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.
- Cache Creek
- Headwaters To Mouth
Track Lake Helen 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 Lake Helen
Where does the data for Lake Helen 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 Lake Helen.