Mountain Island dam
Mountain Island
Mountain Island is a captivating hydroelectric dam located in North Carolina, specifically in Gaston County near Mount Holly. Built in 1923 by the Catawba Manufacturing and Electric Power Company, this gravity-type dam stands at 140 feet tall and has a structural height of 95 feet. With a normal storage capacity of 45,970 acre-feet and a drainage area of 1,860 square miles, Mountain Island serves the dual purposes of hydroelectric power generation and water supply.
Situated on the Catawba River, Mountain Island dam has a spillway width of 997 feet and a maximum discharge capacity of 383,685 cubic feet per second. The dam's hazard potential is classified as high, with a moderate risk assessment rating. Despite not being state-regulated, the Federal Energy Regulatory Commission oversees its operation, inspection, and regulatory aspects. With its impressive design and historical significance, Mountain Island is a key player in water resource management and climate resilience efforts in the region.
As a vital part of the region's infrastructure, Mountain Island dam plays a crucial role in providing renewable energy and water resources to the surrounding communities. Its multi-arch core type and rock foundation contribute to its structural integrity, while its scenic location on the Catawba River adds to its appeal for water resource and climate enthusiasts. With a long history of operation and maintenance, Mountain Island continues to be a significant asset in the quest for sustainable water management practices in North Carolina.
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 Mountain Island -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Long Creek Nr Rhyne | 10 cfs | → |
| Long Creek Near Paw Creek | 2 cfs | → |
| Mcdowell Creek Nr Charlotte | 1 cfs | → |
| Gar Creek At Sr2074 Nr Croft | · | → |
| Paw Cr At Wilkinson Blvd Nr Charlotte | 7 cfs | → |
| Killian Creek Near Mariposa | 9 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mountain Island .
Boat launches
- Riverbend Boat Ramp
- East Charlotte Avenue Downtown
- Neck Road 5744, Huntersville
- Wilkinson Boulevard Belmont
- Nc 73 Mecklenburg County
- Shipley Lane Lincoln County
Campgrounds
- Mcdowell Nature Preserve
- Ebenezer County Park
- Shepherds Field
- Hounds Gateway Campground
- Sign Language
- Kings Mountain State Park
Fishing spots
- Mountain Island Park Fishing Access
- Benfield Creek
- Buck Branch
- Abbotts Creek
- Buddle Branch
- Badin Lake Lakemont Rd
Track Mountain Island 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 Mountain Island
Where does the data for Mountain Island 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 Mountain Island .