Clennon dam
Clennon
Clennon, located in Weld County, Colorado, is a privately-owned irrigation dam built in 1879 on the St. Vrain Creek-OS. Standing at a height of 14 feet, with a hydraulic height of 10 feet, and a length of 2000 feet, this earth dam serves the primary purpose of irrigation. With a storage capacity of 147 acre-feet, Clennon plays a significant role in managing water resources in the area.
Despite its age, Clennon is rated as being in satisfactory condition, with a significant hazard potential due to its uncontrolled spillway type. Regular inspections are conducted on this dam, with the last assessment done in November 2019. The risk assessment for Clennon is moderate, with a DSAC (Dam Safety Action Classification) of 3, indicating a need for ongoing risk management measures to ensure the safety and integrity of the structure.
Enthusiasts of water resources and climate will find Clennon to be a fascinating example of historical water infrastructure in Colorado. Its role in irrigation and water management, combined with its unique design features and risk assessment, make it a noteworthy site for those interested in the intersection of water resources and engineering.
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 Clennon -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| St. Vrain Creek At Mouth | 181 cfs | → |
| St Vrain Cr Blw Boulder Cr At Hwy 119 Nr Longmont | 181 cfs | → |
| St. Vrain Creek Below Longmont | -999,999 cfs | → |
| Boulder Creek At Mouth | 44 cfs | → |
| Big Thompson River At Loveland | 120 cfs | → |
| Big Thompson River At Mouth | 74 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Clennon.
Boat launches
- Lagerman Trail Boulder County
- Boat Ramp Larimer County
- Brighton
- Adams County
- Standley Lake Trail Westminster
- West 69th Avenue 4700, Westminster
Campgrounds
- St. Vrain State Park
- Union Reservoir
- Boulder County Fairground
- Missile Site Park
- Boyd Lake State Park
- Carter Lake - South Side Campgrounds
Fishing spots
- Mead Ponds
- Johnstown Reservoir
- St. Vrain State Park (Barbour Ponds)
- Union Reservoir
- Ehrlich Lake
- Roberts Lake
Paddle runs
- October Hole
- Black Bear Hole & A-Hole
- Ssv - Confluence To Picnic Grounds
- Lower Boulder Canyon
- Main Section
- Gnar Section
More reservoirs
Track Clennon 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 Clennon
Where does the data for Clennon 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 Clennon.