Last Chance No. 1 dam
Last Chance No. 1
Last Chance No. 1, also known as Upper Twin Lake, is a privately owned earth dam located in Westminster, Colorado. Completed in 1892 for irrigation purposes, this historic structure stands at 14 feet high and spans a length of 810 feet, with a storage capacity of 150 acre-feet. Situated on Big Dry Creek-OS, this dam serves multiple functions including fire protection, stock watering, and recreational use in addition to its primary irrigation role.
Despite its age, Last Chance No. 1 has a low hazard potential and is currently rated as not assessed for condition. The last inspection took place in 1986, with a moderate risk assessment given a ranking of 3. While the dam meets state regulatory requirements for permitting, inspection, and enforcement, there is no Emergency Action Plan (EAP) in place, indicating a potential area for improvement. Overall, this structure presents an intriguing blend of historical significance and modern challenges in water resource management.
For water resource and climate enthusiasts, Last Chance No. 1 offers a glimpse into the intersection of past engineering achievements and contemporary dam safety considerations. With its location in a picturesque setting in Jefferson County, Colorado, this dam serves as a reminder of the importance of maintaining and monitoring aging infrastructure to ensure both water supply reliability and public safety. As efforts continue to address potential risks and enhance emergency preparedness, Last Chance No. 1 remains a fascinating case study in the ongoing management of water resources in the face of changing environmental conditions.
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 Last Chance No. 1 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Coal Creek Near Plainview | 1 cfs | → |
| Little Dry Creek At Westminster | 5 cfs | → |
| Big Dry Creek At Westminster | 2 cfs | → |
| Clear Creek At Golden | 122 cfs | → |
| South Platte River At Denver | 158 cfs | → |
| Clear Creek At Mouth | 25 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Last Chance No. 1.
Boat launches
- Standley Lake Trail Westminster
- Ralston Creek Trail Arvada
- West 69th Avenue 4700, Westminster
- Miramonte Road Boulder County
- Fisherman's Trail Lakewood
- C-470 Trail Lakewood
Campgrounds
- Tipi Village
- Standley Lake
- Clear Creek Rv Park
- Camp Patiya
- Gennessee Ropes Camp Spot
- Rifleman Phillips Group Campground
Fishing spots
Paddle runs
- Golden Whitewater Park
- Tunnel 1 To Golden Whitewater Park
- Lower Boulder Canyon
- Idledale To Morrison
- Upper Clear Creek
- Upper South Boulder Creek
More reservoirs
Track Last Chance No. 1 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 Last Chance No. 1
Where does the data for Last Chance No. 1 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 Last Chance No. 1.