Rock Island dam
Rock Island
Rock Island is a gravity-type dam located on the Columbia River in Washington, with a height of 71 feet and a hydraulic height of 55.1 feet. Completed in 1932, the dam serves the primary purpose of hydroelectric power generation and flood risk reduction. It has a storage capacity of 131,000 acre-feet and a drainage area of 89,400 square miles, making it a crucial water resource infrastructure in the region.
Managed by the Federal Energy Regulatory Commission, Rock Island has a controlled spillway width of 961 feet and 31 slide gates for water control. With a hazard potential rated as high and a risk assessment indicating very high risk, the dam's emergency action plan is crucial for public safety. Despite its age, the dam's condition assessment is not available, emphasizing the need for ongoing monitoring and maintenance to ensure its structural integrity and long-term functionality for water resource management in the area.
Rock Island's association with Stone & Webster Engineering Corporation underscores its historical significance in water resource development. As a key player in the region's hydroelectric landscape, the dam's operations and maintenance are vital for ensuring water security and climate resilience in the face of changing environmental conditions. For water resource and climate enthusiasts, Rock Island represents a blend of engineering excellence, environmental stewardship, and critical infrastructure for sustainable water management in the Pacific Northwest.
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 Rock Island -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Wenatchee River At Monitor | 4,590 cfs | → |
| Entiat River Near Entiat | 1,080 cfs | → |
| Wenatchee River At Peshastin | 4,710 cfs | → |
| Mad River At Ardenvoir | 208 cfs | → |
| Chelan River At Chelan | 268 cfs | → |
| Icicle Creek Above Snow Creek Near Leavenworth | 1,050 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Rock Island.
Boat launches
- Russ Road Chelan County
- Spanish Castle Road Douglas County
- Apple Capital Recreation Loop Trail, East Wenatchee
- Apple Capitol Recreational Loop Trail, Wenatchee
- Apple Capital Recreation Loop Trail, Wenatchee
- Chelan County
Campgrounds
- Duffy / Douglas Creek
- Squilchuck State Park Campground
- Douglas Creek Dispersed - Yakima River Canyon Dispersed
- Wenatchee Confluence State Park
- North Douglas Creek
- Stan Coffin - Wdfw
Paddle runs
- Douglas Creek
- Outlet Of Lake Wenatchee To Wenatchee Nf Boundary
- Alpine Lakes Wilderness Boundary To City Of Leavenworth Water Intake In Se1/4 Of Sec 28, T24n, R17e
- Glacier Peak Wilderness Boundary To Confluence With Wenatchee River
- Yakima River Segment 1
- Rock Island Campground To Ida Creek
Track Rock Island 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 Rock Island
Where does the data for Rock Island 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 Rock Island.