Patterson #2 Dam
Patterson #2
Patterson #2 is a privately owned dam located in Lazear, Colorado, along the Leroux Creek. Built in 1908, this earth dam stands at a height of 16 feet and has a storage capacity of 149 acre-feet, primarily used for irrigation purposes. The dam has a fair condition assessment and a low hazard potential, with a maximum discharge of 210 cubic feet per second.
Despite its relatively low risk level, Patterson #2 is subject to state regulation, inspection, and enforcement by the Colorado Division of Water Resources. The dam does not have a spillway, but features slide and uncontrolled outlet gates for water release. With a surface area of 7 acres, this structure plays a crucial role in water supply management for the surrounding area and supports agricultural activities in the region.
For water resource and climate enthusiasts, Patterson #2 serves as a noteworthy example of early 20th-century dam engineering in Colorado. Its location in the picturesque Delta County adds to its significance, as it contributes to the irrigation infrastructure along Leroux Creek. While the dam is deemed to have a fair condition and a low hazard potential, ongoing inspections and regulatory oversight ensure its safe operation and maintenance for the benefit of the local community and ecosystem.
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 Patterson #2 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Surface Creek Near Cedaredge | 31 cfs | → |
| E Fork Terror Cr Blw Cottonwood Stomp Nr Bowie | 0 cfs | → |
| North Fork Gunnison River Below Paonia | 17 cfs | → |
| Surface Creek At Cedaredge | 17 cfs | → |
| Terror Creek At Mouth Near Bowie | 2 cfs | → |
| Hubbard Creek Above Iron Point Gulch Nr Bowie | 6 cfs | → |
About Patterson #2
Where does the data for Patterson #2 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 below 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.
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.