Granger Dam dam
Granger Dam
Granger Dam, also known as Granger Lake, is a Federal-owned water supply dam located in Laneport, Williamson County, Texas. Completed in 1979, this Earth dam serves multiple purposes including fish and wildlife pond, flood risk reduction, recreation, and of course, water supply for the region. With a height of 115 feet and a storage capacity of 650,000 acre-feet, the dam poses a high hazard potential due to its location on the San Gabriel River.
Despite the risks associated with the dam, USACE Fort Worth District has implemented various risk management measures to ensure the safety and stability of Granger Dam. Regular inspections, surveillance, and monitoring are conducted to detect potential concerns, especially during high water levels. Additionally, the district works closely with local emergency managers to develop and update evacuation plans, conduct emergency exercises, and communicate risks to stakeholders. Although the dam reduces flooding risk downstream, the possibility of a breach could have severe consequences for nearby rural communities and cities, emphasizing the importance of continued vigilance and proactive risk mitigation efforts.
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 Granger Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| San Gabriel Rv At Laneport | 1,650 cfs | → |
| Willis Ck Nr Granger | 60 cfs | → |
| Little Rv Nr Little River | 1,510 cfs | → |
| Little Rv Nr Rockdale | 951 cfs | → |
| Berry Ck At Airport Rd Nr Georgetown | 128 cfs | → |
| Salado Ck At Salado | 110 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Granger Dam.
Boat launches
- Williamson County
- County Road 347 1520, Granger
- Lake Pflugerville Park
- Lake Overlook Road 598, Georgetown
- Cedar Breaks Park Road, Georgetown
- Park Road 3, Georgetown
Campgrounds
- Wilson Fox - Granger Lake
- Taylor - Granger Lake
- Willis Creek - Granger Lake
- Berry Springs Park And Preserve
- Cedar Breaks - Lake Georgetown
- Jim Hogg - Lake Georgetown
Fishing spots
Track Granger 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 Granger Dam
Where does the data for Granger 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 Granger Dam.