Dam Report

Morris dam

California, USA San Gabriel River Hazard High
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Tonight low
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Dam height
245ft
Hazard rating
High
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Morris -- None dam
Morris None · San Gabriel River
About this dam

Morris

Morris Reservoir, located in Azusa, California, is a gravity dam completed in 1935 primarily for flood risk reduction. With a height of 245 feet and a storage capacity of 27,500 acre-feet, it plays a crucial role in protecting the surrounding areas from potential flooding events. The dam is state-regulated, inspected, and enforced by the Department of Water Resources (DWR) and the Safety of Dams agency, ensuring its structural integrity and safety.

Situated on the San Gabriel River, Morris Reservoir also serves as a water supply source for the region, highlighting its dual purpose in flood control and water management. The reservoir covers an area of 420 acres and has a drainage area of 210 square miles, making it a vital asset for water resource enthusiasts. Despite its high hazard potential, the dam's condition assessment in 2017 deemed it satisfactory, indicating a well-maintained and monitored structure.

Represented by Congresswoman Judy Chu (D), Morris Reservoir stands as a key infrastructure project in the Los Angeles District managed by the local government. With regular inspections and a comprehensive emergency action plan, the dam ensures public safety and environmental protection. Its historical significance, combined with its crucial role in water supply and flood control, makes Morris Reservoir a fascinating site for climate and water resource enthusiasts alike.

StateNone
River / streamSan Gabriel River
NID IDCA00216
Owner typeLocal Government
Primary purposeFlood Risk Reduction
Dam typeGravity
Year built1935
Dam height245 ft
Dam length750 ft
Max storage27,500 AF
Surface area420.0 ac
Drainage area210.0 sq mi
Hazard potentialHigh
ConditionSatisfactory
Last inspectionTue, 02 Feb 2021 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 Morris -- inflows here typically show up in storage 24-72 hours later.

Track Morris 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 Morris

Where does the data for Morris 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.