Dam Report

Chollas dam

California, USA Tr Chollas Creek Hazard High
Today high
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Tonight low
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Dam height
50ft
Hazard rating
High
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Chollas -- None dam
Chollas None · Tr Chollas Creek
About this dam

Chollas

Chollas Reservoir, located in San Diego, California, serves as a critical water resource managed by the local government. With a primary purpose of hydroelectric power generation and water supply, this earth dam stands at a height of 50 feet, with a hydraulic height of 40.4 feet. Completed in 1901, Chollas Reservoir has a storage capacity of 167 acre-feet and covers a surface area of 18 acres, drawing water from the Tr Chollas Creek.

Maintained by the California Department of Water Resources (DWR) and regulated by the Safety of Dams agency, Chollas Reservoir is subject to state permitting, inspection, and enforcement to ensure its structural integrity and safe operation. Despite its high hazard potential, the dam's condition assessment as of September 2017 is deemed satisfactory. With a notable proximity to the city of San Diego and under the jurisdiction of the state, Chollas Reservoir plays a vital role in water management and hydroelectric power generation for the region.

As a key component of the local water infrastructure, Chollas Reservoir not only contributes to water supply and hydroelectricity but also serves as a crucial asset for climate resilience in the face of changing environmental conditions. With its significant historical importance and ongoing regulatory oversight, Chollas Reservoir stands as a testament to the intersection of water resource management, climate adaptation, and infrastructure safety in California's dynamic landscape.

StateNone
River / streamTr Chollas Creek
NID IDCA00107
Owner typeLocal Government
Primary purposeHydroelectric
Dam typeEarth
Year built1901
Dam height50 ft
Dam length565 ft
Max storage167 AF
Surface area18.0 ac
Drainage area0.1 sq mi
Hazard potentialHigh
ConditionSatisfactory
Last inspectionWed, 28 Oct 2020 00:00:00 GMT

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.
Detailed forecast

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.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

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.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Chollas -- inflows here typically show up in storage 24-72 hours later.

Track Chollas 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.

FAQ

About Chollas

Where does the data for Chollas 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.

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Premium feature

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Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this dam, set a threshold, and you'll get a push the moment conditions cross.

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