Lake Johnson Dam dam
Lake Johnson Dam
Lake Johnson Dam, located in Wake County, North Carolina, serves as a vital water supply structure for the surrounding area. Built in 1914, this earth dam stands at a hydraulic height of 37 feet and a structural height of 40 feet, with a length of 779 feet. The dam has a storage capacity of 3090 acre-feet, providing essential water resources for the region.
Managed by the local government and regulated by the North Carolina Department of Environmental Quality, Division of Energy, Mineral, and Land Resources, the dam is classified as having a high hazard potential but is currently in fair condition. Regular inspections are conducted every two years to ensure the safety and integrity of the structure. Despite its age, Lake Johnson Dam continues to play a crucial role in water supply management and flood control along Walnut Creek.
With a surface area of 147.5 acres and a drainage area of 4403 acres, Lake Johnson Dam not only provides water storage but also offers recreational opportunities for the community. The dam's presence has helped to mitigate potential flood risks and ensure a reliable water supply for residents in the Raleigh area. As climate change impacts water resources, the maintenance and upkeep of structures like Lake Johnson Dam become increasingly important for sustainable water management in 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 Lake Johnson Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Rocky Branch Below Pullen Drive At Raleigh | 0 cfs | → |
| Swift Creek Near Apex | 0 cfs | → |
| Swift Creek Near Mccullars Crossroads | 13 cfs | → |
| Crabtree Creek At Hwy 70 At Raleigh | 13 cfs | → |
| Crabtree Cr At Ebenezer Church Rd Nr Raleigh | 13 cfs | → |
| Crabtree Creek At Us 1 At Raleigh | 17 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lake Johnson Dam.
Boat launches
- Walnut Creek Trail Raleigh
- Lake Wheeler Boat Ramp
- Lake Trail Wake County
- Milburnie Dam Bridge Raleigh
- Neuse River Trail Wake County
- Neuse River Trail Raleigh
Campgrounds
- William B. Umstead State Park
- Durant Nature Park
- Blue Heron Campground
- Osprey Nest Campground
- Bootleg Point Campground
- Crosswinds State Rec Area - Jordan Lake
Track Lake Johnson Dam 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 Lake Johnson Dam
Where does the data for Lake Johnson Dam 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 Lake Johnson Dam.