Johnson dam
Johnson
Johnson is a privately owned dam located in Larimer County, Colorado, with a primary purpose of irrigation. Built in 1944, this earth dam stands at a height of 8 feet and has a length of 450 feet. With a maximum storage capacity of 573 acre-feet and a normal storage of 133 acre-feet, Johnson serves as a vital source of water for the surrounding area.
The dam is situated on Slough Creek-TR and is regulated by the Colorado Division of Water Resources. Despite having a low hazard potential, Johnson's condition assessment in 2014 deemed it unsatisfactory. It has a moderate risk rating and is inspected every 6 years. The spillway, with a width of 200 feet, is uncontrolled, and the dam has a maximum discharge capacity of 2600 cubic feet per second.
In the event of an emergency, it is crucial that proper risk management measures are in place for Johnson to ensure the safety of downstream areas. With its historic significance and importance for irrigation purposes, the maintenance and upkeep of Johnson are essential for water resource and climate enthusiasts to monitor and support.
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 Johnson -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Laramie River Near Glendevey | 73 cfs | → |
| Laramie R Bl Pioneer Canal Nr Woods Landing | 1,010 cfs | → |
| Pioneer Canal Near Woods | 174 cfs | → |
| Sand Creek At Colorado-Wyoming State Line | 3 cfs | → |
| North Platte River Near Northgate | 167 cfs | → |
| Michigan River At Walden | 37 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnson.
Boat launches
- Cowdrey Lake Rec Site Boat Dock
- Cowdrey Lake Rec Site Boat Ramp
- Nowata Drive 597, Larimer County
- Nowata Drive 407, Larimer County
- Nowata Drive 875, Larimer County
- Albany County
Campgrounds
- Jelm Wildlife Habitat Management Area Camping
- North Sand Hills Rec Area Campsite
- North Sand Hills - Kremmling Rma
- Browns Park Campground
- Evans Creek
- Browns Park
Fishing spots
Paddle runs
- South Sec Line, Sec 2, T11n, R80w To Co/Wy Stateline
- Source In Se 1/4 Sec 25, T10n, R75w To End Of The Four-Wheel Drive Road East Of The Nf Poudre Campground (Nw 1/4 Of Sec 21, T10n, R74w
- End Of Four-Wheel Drive Road To Pearl Creek In Se 1/4 Sec 21, T10n, R74w
- Northgate Canyon
- Spencer Heights
- Pearl Creek To Junction Of Road West Of Creedmore Lakes In Sw 1/4 Sec 5, T10n, R73e
More reservoirs
Track Johnson 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 Johnson
Where does the data for Johnson 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 Johnson.