Long Lake Dam dam
Long Lake Dam
Long Lake Dam in Cobb, Georgia, stands as a pivotal structure for water resource and climate enthusiasts. This private dam, primarily used for recreation, is an earth-type dam with a height of 33 feet and a hydraulic height of 20 feet. Although the dam is not state-regulated, it is inspected periodically to ensure its structural integrity and safety. With a low hazard potential and a moderate risk assessment rating, Long Lake Dam plays a crucial role in managing water resources in the area.
Located within the Savannah District, Long Lake Dam provides a surface area of 2 acres and a maximum storage capacity of 33 acre-feet. While the dam's spillway is uncontrolled, the risk management measures in place help mitigate potential hazards associated with the structure. Despite not being federally owned or funded, the dam's importance in water management and recreation cannot be understated, making it a key point of interest for those interested in water resource management and climate resilience.
Even though Long Lake Dam's last inspection dates back to 1992, the structure's condition assessment remains ungraded, indicating the need for updated evaluations to ensure its continued safety and functionality. With its strategic location and purpose, Long Lake Dam serves as a vital component in the local water infrastructure, offering opportunities for recreation while also contributing to the overall water resource management efforts 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 Long Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Sope Creek Near Marietta | 10 cfs | → |
| Chattahoochee River Below Morgan Falls Dam | 1,010 cfs | → |
| Chattahoochee River Above Roswell | 615 cfs | → |
| Nancy Creek At Rickenbacker Drive | 7 cfs | → |
| Chattahoochee River At Atlanta | 922 cfs | → |
| Nancy Creek At West Wesley Road | 11 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Long Lake Dam.
Boat launches
- Johnson Ferry Road Southeast Sandy Springs
- Riveredge Lane Northwest Sandy Springs
- West Palisades Vinings
- Cobb Parkway South Vinings
- Chattahochee River Park Peachtree Corners
- Lake Windward Landing 139, Alpharetta
Campgrounds
- Dobbins Lakeside Military
- Payne - Allatoona Lake
- Victoria - Allatoona Lake
- Clark Creek South - Allatoona Lake
- Clark Creek North - Allatoona Lake
- Sweetwater - Allatoona Lake
Fishing spots
Track Long Lake 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 Long Lake Dam
Where does the data for Long Lake 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 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 Long Lake Dam.