Sonoma Hills dam
Sonoma Hills
Sonoma Hills is a privately owned dam located in Lakeville, California, serving as a crucial water supply infrastructure for irrigation, recreation, and water supply purposes. Completed in 1991, this earth dam stands at a height of 38 feet and has a storage capacity of 240 acre-feet. Situated on the Tr Tolay Creek, the dam plays a vital role in water resource management within Sonoma County, California.
With a low hazard potential and a satisfactory condition assessment, Sonoma Hills has been regulated, permitted, inspected, and enforced by the California Department of Water Resources (DWR) under the Safety of Dams program. The dam is regularly inspected, with the last assessment conducted in September 2019, ensuring its safety and functionality. The surrounding area, covering 29 acres, provides a valuable water source for the community while also offering recreational opportunities for residents and visitors.
As an essential component of the local water infrastructure, Sonoma Hills contributes to the sustainable management of water resources in Sonoma County. With its strategic location and reliable performance, the dam represents a successful collaboration between private ownership and state regulatory agencies in ensuring the safety and efficiency of water supply operations in the region. Climate and water resource enthusiasts can appreciate the role of Sonoma Hills in supporting irrigation, recreation, and water supply needs while maintaining a high standard of safety and environmental stewardship.
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 Sonoma Hills -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Nathanson C A Sonoma Ca | 0 cfs | → |
| Petaluma R A Copland Pumping Station A Petaluma Ca | 90 cfs | → |
| Sonoma C A Agua Caliente Ca | 10 cfs | → |
| Novato C A Novato Ca | 1 cfs | → |
| Copeland C A Rohnert Park Ca | 2 cfs | → |
| Sonoma Creek A Kenwood Ca | 2 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Sonoma Hills.
Boat launches
- Sears Point Road 100-138, Novato
- Calypso Shores 23, Marin County
- Cuttings Wharf Road 3270, Napa
- Cuttings Wharf Road 3175-3337, Napa
- Napa Valley Vine Trail, Napa
- Steven Way 98, Marin County
Campgrounds
- Camp Via (Sonoma Developmental Center)
- Napa Valley Expo
- China Camp State Park
- Skyline Wilderness County Park
- Sugarloaf Ridge State Park
- Browers Garden Camping - No Reservation Needed
Fishing spots
- Lake Ralphine
- Lake Lagunitas
- 9th Street Boat Ramp
- City Of Benicia Fishing Pier
- San Pablo Reservoir
- Berkeley Yacht Harbor
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.
- Headwaters To Mouth
- Cache Creek
Track Sonoma Hills 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 Sonoma Hills
Where does the data for Sonoma Hills 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 Sonoma Hills.