Plotz Dam dam
Plotz Dam
Plotz Dam, located in Johnson County, Iowa, is a privately owned earth dam with a primary purpose of recreation. Completed in 1968 by the USDA NRCS, this dam stands at a height of 28 feet and stretches 287 feet in length, creating a reservoir with a storage capacity of 44 acre-feet. The dam is situated on the TR-Knapp Creek, within the Coralville Reservoir area, providing a serene setting for water and climate enthusiasts to enjoy various recreational activities.
With a low hazard potential and a moderate risk assessment rating, Plotz Dam is regulated by the Iowa Department of Natural Resources, ensuring that it meets necessary safety standards. The dam does not have outlet gates or locks but features an uncontrolled spillway. The surrounding area boasts a surface area of 3.8 square miles and a drainage area of 0.3 square miles, offering a picturesque environment for visitors to explore and appreciate the intersection of water resources and climate within the region.
While the condition of Plotz Dam is currently not rated, its overall risk management measures are deemed satisfactory, providing a level of assurance to those who frequent the reservoir. With its tranquil waters and scenic surroundings, Plotz Dam serves as a valuable recreational resource within the community, inviting water resource and climate enthusiasts to experience the beauty and importance of sustainable water management practices in action.
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 Plotz Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Clear Creek Near Oxford | 26 cfs | → |
| Cedar River At Cedar Rapids | 4,490 cfs | → |
| Iowa River At Marengo | 2,410 cfs | → |
| Clear Creek Near Coralville | 29 cfs | → |
| Iowa River Below Coralville Dam Nr Coralville | 2,140 cfs | → |
| Iowa River At Iowa City | 2,160 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Plotz Dam.
Boat launches
- Poplar Avenue Northeast Big Grove Township
- Falcon Lane Big Grove Township
- Mehaffey Bridge Road Northeast , 52333 Iowa
- Anglers Point Road Northeast Big Grove Township
- Lake Mcbride Road Northeast Big Grove Township
Track Plotz 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 Plotz Dam
Where does the data for Plotz 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 Plotz Dam.