Spence dam
Spence
Spence is a privately owned earth dam located in Archuleta, Colorado, serving primarily for irrigation purposes. Built in 1965, this structure stands at a height of 44 feet, with a hydraulic height of 48 feet and a structural height of 58 feet. It has a storage capacity of 617 acre-feet, with a normal storage level of 425 acre-feet and a maximum discharge of 4243 cubic feet per second.
The dam is situated on Spence Creek, with a drainage area of 2 square miles and a surface area of 32 acres. It features an uncontrolled spillway with a width of 110 feet and is inspected every two years, with the last assessment in December 2020 rating its condition as satisfactory. With a significant hazard potential and a moderate risk assessment, Spence is a vital infrastructure for water resource management in the region, contributing to fire protection, stock watering, and wildlife conservation efforts.
Managed by the Colorado Division of Water Resources, Spence plays a crucial role in supporting the agricultural activities in the area, while also ensuring the safety and well-being of the surrounding communities. With its strategic location and reliable design, this dam continues to be a key asset for water supply and climate resilience in Colorado, highlighting the importance of sustainable water resource management 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 Spence -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Rio Blanco Bl Blanco Div Dam | 42 cfs | → |
| Navajo River Bl Oso Diversion Dam Nr Chromo | 92 cfs | → |
| Navajo R At Banded Peak Ranch | 267 cfs | → |
| San Juan River At Pagosa Springs | 897 cfs | → |
| East Fork San Juan River Nr Pagosa Springs | -888 cfs | → |
| Conejos River Below Platoro Reservoir | 330 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Spence.
Campgrounds
Fishing spots
- Echo Canyon Reservoir
- Platoro Reservoir
- Trujillo Meadows Boating Site
- Trujillo Meadows Lake
- Spectacle Lake Fishing Site
- Alberta Park Reservoir
Paddle runs
- Sec 1, T33n, R3e To Confluence With East Fork--Sec 17, T33n, R4e
- Dipping Lakes--Sec 5, T33n, R4e To Confluence With West Fork--Sec 17, T33n, R4e
- Lower Branch--Sec 28, T33n, R3e; Upper Branch--Sec 15, T33n, R3e To Sec 7, T32n, R4e
- North Fork--Sec 8, T35n, R2e To Confluence With Middle Fork
- Middle Fork--Sec 13, T35n, R2e To Confluence Of Three Forks--Sec 14, T35n, R3e
- El Rito Azul--Blue Lake (Sec 26, T35n, R3e) And Portion Of Conejos Above Platoro Reservoir To Upper Reach Of Platoro Reservoir--Sec 6, T35n, R4e
Track Spence 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 Spence
Where does the data for Spence 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 Significant 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 Spence.