Byllesby dam
Byllesby
Byllesby, a gravity dam located in Virginia's Carroll County, stands as a testament to the intersection of hydroelectric power and recreational opportunities. Completed in 1912, this multi-arch concrete structure spans 970 feet and reaches a height of 63 feet, providing a storage capacity of 2034 acre-feet. The dam's primary purpose is hydroelectric power generation, with a secondary focus on recreation, offering visitors a chance to enjoy the scenic beauty of the New River.
Managed by the Federal Energy Regulatory Commission, Byllesby Dam boasts a controlled spillway width of 656 feet and a maximum discharge capacity of 436,000 cubic feet per second. With a hazard potential rated as high and a risk assessment indicating a very high risk level, the dam's safety and emergency preparedness measures are crucial. While the condition assessment is not available, regular inspections ensure the integrity of this vital water resource infrastructure. Overall, Byllesby Dam is a key player in meeting Virginia's energy needs while offering a picturesque backdrop for outdoor enthusiasts and climate advocates alike.
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 Byllesby -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| New River At Ivanhoe | 632 cfs | → |
| Chestnut Creek At Galax | 24 cfs | → |
| New River Near Galax | 535 cfs | → |
| Reed Creek At Grahams Forge | 91 cfs | → |
| New River At Allisonia | 968 cfs | → |
| Little River At Graysontown | 123 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Byllesby .
Boat launches
- New River Trail Carroll County
- Ivanhoe Boat Launch
- Pattons Mill Lane 1434, Grayson County
- Riverside Boat Ramp
- Va 100 Wythe County
- Baywood Boat Ramp
Campgrounds
- Sunrise Cabin
- Cliffview Campground
- Raven Cliff Campground
- Raven Cliff
- Raven Cliff Recreation Area
- Comers Rock Recreation Area
Fishing spots
Paddle runs
- The U.S. Route 460 Bridge In Glen Lyn, Virginia To The Maximum Summer Pool Elevation Of Bluestone Lake, South Of Hinton, West Virginia
- Whitetop Laurel--Jefferson Nf Boundary (Intersection Of Hwy 58 And Sr 859) To Jefferson Nf Boundary Above Damascus
- Green Cove--Jefferson Nf Near Confluence Of Star Hill Branch To Confluence With Whitetop Laurel
- Jefferson Nf Boundary (Above Cascades Fall) To Jefferson Nf Boundary (Below Cascades Fall)
- Jefferson Nf Boundary Near Confluence With Nettle Hollow To Confluence With Laurel Branch
More reservoirs
Track Byllesby 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 Byllesby
Where does the data for Byllesby 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 Byllesby .