Johnson dam
Johnson
Located in La Plata, Colorado, Johnson Reservoir, also known as Lake Durango, is a private water supply dam designed by HARRY GOFF and completed in 1982. The dam stands at a height of 41 feet, with a hydraulic height of 46 feet and a structural height of 55 feet. With a storage capacity of 1320 acre-feet and a surface area of 55 acres, Johnson Reservoir serves as a vital source of water for the surrounding area.
Managed by the Colorado Division of Water Resources, Johnson Reservoir is regulated and inspected regularly to ensure its safety and structural integrity. The dam has a spillway type of Uncontrolled, with a spillway width of 102 feet to manage potential overflow. Despite being classified as having a high hazard potential, the dam's condition assessment currently rates as fair, indicating a moderate risk level. The dam's emergency action plan (EAP) was last revised in February 2017, demonstrating proactive measures in place for emergency situations.
With its strategic location on the Coal Gulch-TR river system and its essential role in water supply, Johnson Reservoir is a key component of Colorado's water infrastructure. As a private dam, it plays a crucial role in water management and supports the local community's water needs. Enthusiasts of water resources and climate will find Johnson Reservoir an intriguing example of sustainable water management practices in action, highlighting the importance of dam safety and regulation in ensuring water security for the region.
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 |
|---|---|---|
| La Plata River At Hesperus | 58 cfs | → |
| Animas River At Durango | 782 cfs | → |
| Animas River Blw Durango Pump Plant Nr Durango | 777 cfs | → |
| Florida R Bl Flor Farmers Ditch | 13 cfs | → |
| Salt Creek Near Oxford | -888 cfs | → |
| Florida River At Bondad | -888 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnson.
Campgrounds
Fishing spots
Paddle runs
- Confluence With Rincon La Vaca And North Fork To Northern Line Of Granite Peak Ranch
- West Dolores---Source To Confluence With Mainstem
- Lake Creek--Headwaters To Confluence With Los Pinos
- Fdr 631 To Indian Creek
- Indian Creek To Co Hwy 160
- Flint Creek--Headwaters To Confluence With Los Pinos
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 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 Johnson.