Big Creek #4 dam
Big Creek #4
Big Creek #4, also known as Forty Acre Lake, is a privately owned irrigation reservoir located in Mesa County, Colorado. Built in 1893, this earth dam stands at 15 feet high with a hydraulic height of 18 feet and a length of 200 feet. The reservoir has a storage capacity of 388 acre-feet and serves multiple purposes including irrigation, recreation, and water supply.
The dam, primarily constructed with stone core and resting on rock and soil foundations, underwent modifications in 1970 to enhance its hydraulic, mechanical, and structural components. With a spillway width of 15 feet and a maximum discharge capacity of 970 cubic feet per second, Big Creek #4 is classified with a low hazard potential and fair condition assessment. Despite its moderate risk rating, the dam is regularly inspected every 6 years to ensure its safety and stability.
The reservoir's emergency action plan (EAP) was last revised in 2005, and it meets regulatory guidelines. In case of a potential emergency, the dam is equipped with a slide outlet gate for controlled water release. With its picturesque surroundings and vital role in irrigation and water supply, Big Creek #4 remains a significant water resource in the region, serving both agricultural and recreational needs while adhering to state regulatory standards.
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 Big Creek #4 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Big Creek At Upper Station | 20 cfs | → |
| Surface Creek Near Cedaredge | 34 cfs | → |
| Surface Creek At Cedaredge | 39 cfs | → |
| Plateau Creek Near Cameo | 23 cfs | → |
| E Fork Terror Cr Blw Cottonwood Stomp Nr Bowie | 0 cfs | → |
| Colorado River Near Cameo | 2,150 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Big Creek #4.
Boat launches
- Forest Road 121 Mesa County
- Big Creek Reservoir Boat Launch Grand Valley Rd
- Forest Road 125 Delta County
- Lakeshore Drive Delta County
- Ward Lake Boat Access - Grand Valley Rd
- Z Road Delta County
Campgrounds
- Bonham Lake City Park
- Big Creek Campground - Grand Valley Rd
- Big Creek
- Collbran - Cottonwood Lake
- Cottonwood Lake Campground - Grand Valley Rd
- Eggleston
Fishing spots
- Bonham Reservoir
- Silver Lake (Grand Mesa)
- Neversweat Reservoir
- Forty Acre Lake
- Atkinson Reservoir
- Cottonwood Lake #4 (Grand Mesa)
Track Big Creek #4 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 Big Creek #4
Where does the data for Big Creek #4 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 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 Big Creek #4.