Dam Report

Rocky Reach dam

Washington, USA Columbia River Hazard High
Today high
--
Tonight low
--
Dam height
118ft
Hazard rating
High
Loading current conditions…
Loading next 24 hours…
Loading 7-day outlook…
Rocky Reach -- None dam
Rocky Reach None · Columbia River
About this dam

Rocky Reach

Rocky Reach, also known as Lake Entiat, is a gravity dam located on the Columbia River in Washington. Built in 1962 by Stone & Webster Engineering Corporation, this hydroelectric structure stands at a height of 130 feet and spans a length of 3,820 feet. With a storage capacity of 390,000 acre-feet and a maximum discharge of 1,200,000 cubic feet per second, Rocky Reach serves multiple purposes including flood risk reduction and hydroelectric power generation.

Managed by the Federal Energy Regulatory Commission, Rocky Reach is a key player in water resource management and climate resilience in the region. The dam's controlled spillway, Tainter gates, and high hazard potential make it a critical infrastructure for ensuring the safety and stability of the surrounding area. Despite its age, Rocky Reach continues to operate efficiently, with regular inspections and emergency action plans in place to mitigate any potential risks.

As a prominent landmark in Chelan, Washington, Rocky Reach not only contributes to the local economy through hydroelectric power generation but also provides recreational opportunities and environmental benefits. With its strategic location on the Columbia River and state-of-the-art design features, Rocky Reach stands as a testament to sustainable water resource management and climate adaptation efforts in the Pacific Northwest.

StateNone
River / streamColumbia River
NID IDWA00086
Owner typePublic Utility
Primary purposeHydroelectric
Dam typeGravity
Year built1962
Dam height118 ft
Dam length3,820 ft
Max storage390,000 AF
Normal storage382,000 AF
Surface area9,810.0 ac
Drainage area87,800.0 sq mi
Hazard potentialHigh
ConditionNot Available
Last inspectionWed, 30 Sep 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.

Loading hourly forecast…
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
Loading detailed forecast…
Long-term outlook

15-day temperature & precipitation

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

Loading 15-day outlook…
Regional inflow

Nearby streamflow gauges

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

Track Rocky Reach 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 Rocky Reach

Where does the data for Rocky Reach 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.