Lewis dam
Lewis
Lewis Lake, located in San Miguel County, Colorado, is a privately-owned reservoir with a primary purpose of hydroelectric power generation. The dam, completed in 1904, is a rockfill structure standing at 16 feet high and stretching 190 feet in length. With a storage capacity of 175 acre-feet, the reservoir covers an area of 25 acres and is regulated by the Federal Energy Regulatory Commission.
Despite its low hazard potential, Lewis Lake has a moderate risk assessment rating, indicating potential concerns that require monitoring and management. The dam is inspected biennially, with the last assessment conducted in August 2018. It is equipped with an uncontrolled spillway measuring 12 feet in width, capable of discharging up to 100 cubic feet per second. The surrounding area, known for its scenic beauty, is a popular destination for water resource and climate enthusiasts.
Overall, Lewis Lake serves as a critical component of the hydroelectric infrastructure in Telluride, Colorado, contributing to the region's energy needs while also providing recreational opportunities for visitors. As a regulated structure under the oversight of the State and Federal agencies, the dam's operation, maintenance, and safety are closely monitored to ensure the protection of both the environment and the local community. With its historical significance and continued relevance in modern water management practices, Lewis Lake remains a notable landmark in the region.
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 Lewis -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| South Fork San Miguel River Near Ophir | 76 cfs | → |
| Cement Creek At Silverton | 59 cfs | → |
| Mineral Creek At Silverton | 225 cfs | → |
| Animas River At Silverton | 281 cfs | → |
| Animas River Below Silverton | 646 cfs | → |
| Animas River At Howardsville | 262 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lewis .
Boat launches
Campgrounds
- Alta Lakes Campground (Dispersed)
- Telluride Town Park
- Alta Lakes Campground (Designated) - Norwood Rd
- South Mineral
- South Mineral Campground
- Kendall Campground
Fishing spots
- Sheep Corrals Fishing Site
- Andrews Lake Swa
- North Fork Animas River
- Woods Lake
- Ridgway Reservoir
- Haviland Lake
Paddle runs
More reservoirs
Track Lewis 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 Lewis
Where does the data for Lewis 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 Low 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 Lewis .