Terrace dam
Terrace
Terrace, also known as Alamosa River Reservoir, is a privately-owned irrigation structure located in Conejos County, Colorado. Built in 1912 by the USDA NRCS, this Earth-type dam stands at a height of 166 feet and has a hydraulic height of 182 feet, providing crucial water storage for the region. With a storage capacity of 19,195 acre-feet and a surface area of 300 acres, Terrace plays a vital role in supporting agricultural activities along the Alamosa River.
Managed by the Colorado Division of Water Resources, Terrace is subject to state regulation, inspection, and enforcement to ensure its safety and compliance with standards. The dam's spillway, classified as uncontrolled, has a width of 138 feet to manage potential overflow during high-discharge events. Despite being assessed as in fair condition during the last inspection in October 2020, Terrace has a high hazard potential, highlighting the importance of ongoing monitoring and maintenance to mitigate risks to downstream communities.
Terrace's strategic location and design make it a critical water resource infrastructure in the region, with a moderate risk assessment rating. As water resource and climate enthusiasts, understanding the role of structures like Terrace in sustaining irrigation and water supply systems is essential for promoting resilience and sustainable management practices 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 Terrace -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Alamosa River Below Terrace Reservoir | 135 cfs | → |
| Alamosa River Above Terrace Reservoir | 291 cfs | → |
| La Jara Creek At Gallegos Ranch | 7 cfs | → |
| Alamosa River Above Wightman Fork Near Jasper | -999 cfs | → |
| Wightman Fork At Mouth Near Jasper | 3 cfs | → |
| Conejos River Below Platoro Reservoir | 246 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Terrace.
⚓ Boat launches
More boat launches →⛺ Campgrounds
More campgrounds →🎣 Fishing spots
- La Jara Reservoir
- Lost Lake
- Kerr Lake Fishing Site
- Platoro Reservoir
- Spectacle Lake Fishing Site
- La Manga Creek (Beaver Ponds)
🛶 Paddle runs
- Lake Fork--Confluence With South Fork To 1 Mile Below Town Of Platoro
- South Fork--Sec 19, T35n, R4e To Sec 36, T35n, R4 1/2e
- Sec 17, T35n, R4e To Sec 36, T35n, R4e
- 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
- Middle Fork--Sec 13, T35n, R2e To Confluence Of Three Forks--Sec 14, T35n, R3e
- North Fork--Sec 8, T35n, R2e To Confluence With Middle Fork
Track Terrace 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 Terrace
Where does the data for Terrace 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 Terrace.