Terrill Dam dam
Terrill Dam
Terrill Dam, located in Louisa County, Iowa, is a private earth dam completed in 2000 by the NRCS for fire protection and as a stock or small fish pond. With a height of 31 feet and a length of 178 feet, the dam has a storage capacity of 71 acre-feet and serves a drainage area of 0.55 square miles. Situated on TR- Whiskey Run along the Mississippi River, Terrill Dam is regulated by the Iowa DNR and undergoes regular inspections, with a low hazard potential and a moderate risk assessment.
Despite its modest size, Terrill Dam plays a crucial role in water resource management in the region, providing storage for firefighting efforts and supporting local wildlife. The dam's location in a rural area highlights its importance for maintaining water quality and supporting ecological diversity. While not currently rated for its condition, Terrill Dam's construction and management reflect a commitment to sustainability and responsible water use, showcasing the essential role of private infrastructure in climate resilience and natural resource protection.
As climate change continues to impact water resources and ecosystems, Terrill Dam stands as a testament to the importance of small-scale infrastructure in mitigating risks and adapting to changing conditions. With its earth construction and soil foundation, the dam exemplifies a practical solution for local water management needs. By adhering to regulatory standards, undergoing regular inspections, and maintaining a low hazard potential, Terrill Dam sets a positive example for private dam owners in safeguarding water resources and enhancing climate resilience in the face of environmental challenges.
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 Terrill Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cedar River Near Conesville | 6,160 cfs | → |
| Iowa River At Wapello | 10,200 cfs | → |
| Edwards River Near New Boston | 264 cfs | → |
| Iowa River Near Lone Tree | 3,230 cfs | → |
| Pope Creek Near Keithsburg | 76 cfs | → |
| Hoover Crk At Hoover Nat.Hist.Site West Branch | 2 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Terrill Dam.
Boat launches
- 120th Street Louisa County
- F Avenue 9777, Louisa County
- 78th Street Louisa County
- Prairie Street 5898, Louisa County
- Prairie Street 5882, Louisa County
- Muscatine County
Track Terrill 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 Terrill Dam
Where does the data for Terrill 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 Terrill Dam.