Moccasin Lake Dam dam
Moccasin Lake Dam
Moccasin Lake Dam, located in Twisp, Washington, is a privately owned structure primarily used for irrigation purposes. Constructed in 1969, this earth-type dam stands at a hydraulic height of 16.5 feet and a structural height of 9.2 feet, with a total length of 530 feet. The dam has a storage capacity of 261 acre-feet and is situated on the Tr-Thompson Creek-Offstream, serving as a vital water resource for the surrounding area.
Despite its age, Moccasin Lake Dam has been regularly inspected by the Washington Dept of Ecology, with the last assessment in 2019 rating its condition as fair. The dam is considered to have a high hazard potential, highlighting the importance of ongoing maintenance and risk management measures. With a drainage area of 0.53 square miles and a maximum discharge of 35 cubic feet per second, this dam plays a crucial role in regulating water flow and providing water for both irrigation and recreational activities in the region.
As a key component of the local water infrastructure, Moccasin Lake Dam serves as a significant resource for the community, with its upkeep and management essential for ensuring the safety and sustainability of the surrounding area. With its strategic location and important function in water management, this dam is a focal point for water resource enthusiasts and climate advocates interested in the intersection of infrastructure, environmental conservation, and community resilience.
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 Moccasin Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Methow River At Winthrop | 2,870 cfs | → |
| Chewuch River At Winthrop | 914 cfs | → |
| Twisp River Near Twisp | 801 cfs | → |
| Methow River At Twisp | 3,590 cfs | → |
| Methow River Above Goat Creek Near Mazama | 1,400 cfs | → |
| Stehekin River At Stehekin | 3,400 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Moccasin Lake Dam.
Boat launches
- Conconully Road Conconully
- Sinlahekin Road 100-144, Okanogan
- Okanogan County
- Sinlahekin Road, Okanogan
- Green Lake Road 50-374, Okanogan
Campgrounds
- Tent Camping
- Pearrygin Lake State Park
- Cougar Lake Campground
- Bear Creek - Wdfw
- Couger Lake Wdfw
- Campbell Lake - Wdfw
Paddle runs
- Private Land Boundary To Okanogan Nf Boundary
- Lake Chelan-Sawtooth Wilderness Boundary To Okanogan Nf Boundary
- Confluence Of South Fork Wolf Creek To Lake Chelan-Sawtooth Wilderness Boundary
- Lake Chelan-Sawtooth Wilderness Boundary To Private Land Boundary Near Lime Creek In Se1/4 Of Sec 18, T33n, R20e
- Pasayten Wilderness Boundary To Okanogan Nf Boundary
Track Moccasin Lake Dam 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 Moccasin Lake Dam
Where does the data for Moccasin Lake Dam 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 Moccasin Lake Dam.