Black Hollow dam
Black Hollow
Black Hollow is a privately owned irrigation dam located in Weld County, Colorado, specifically in the city of Severance. Built in 1918, this Earth-type dam stands at 40 feet tall and stretches 1,260 feet in length, creating a reservoir with a storage capacity of 9,300 acre-feet. The dam regulates Black Hollow Creek, with a drainage area of 21 square miles, and has a spillway width of 1,820 feet to manage maximum discharge of 38,200 cubic feet per second.
Despite being classified as having a high hazard potential, Black Hollow Dam is currently in satisfactory condition according to its last inspection in June 2020. It is under the regulatory oversight of the Colorado Division of Water Resources and undergoes regular inspections and enforcement to ensure its safety and functionality. The dam serves a crucial purpose in providing irrigation water to the surrounding area, showcasing the intersection of water resource management and climate considerations in the region.
With its historical significance and vital role in water management, Black Hollow Dam serves as a key infrastructure in Weld County. Its presence highlights the importance of maintaining and regulating dams for irrigation purposes, while also emphasizing the need for continued monitoring and risk assessment to address climate-related challenges in water resource management. As water resource and climate enthusiasts, understanding the intricacies of dams like Black Hollow is essential in safeguarding our environment and ensuring sustainable water practices for the future.
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 Black Hollow -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cache La Poudre R Ab Boxelder C | 493 cfs | → |
| Cache La Poudre River At Fort Collins | 365 cfs | → |
| Cache La Poudre River Near Greeley | 60 cfs | → |
| Big Thompson River At Mouth | 54 cfs | → |
| Big Thompson River At Loveland | 127 cfs | → |
| Cache La Poudre R A Mo Of Cn | 733 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Black Hollow.
Boat launches
- Boat Ramp Larimer County
- Filter Plant River Access Point (Put-In)
- Bridges River Access Point (Take-Out)
- Bridges River Access Point (Take-Out #2)
- Bridges River Access Point (Put-In)
- Pineview River Access Point (Put-In, Take-Out)
Campgrounds
- Missile Site Park
- Boyd Lake State Park
- Inlet Bay - Horsetooth Reservoir
- South Bay - Horsetooth Reservoir
- Flatiron Reservoir
- Carter Lake - North Side Campgrounds
Fishing spots
Paddle runs
More reservoirs
Track Black Hollow 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 Black Hollow
Where does the data for Black Hollow 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 Black Hollow.