North Branch Ralston Creek Dam dam
North Branch Ralston Creek Dam
The North Branch Ralston Creek Dam, located in Johnson County, Iowa, was completed in 1983 with a primary purpose of flood risk reduction. Owned by the local government, this earth dam stands at a height of 37 feet and has a length of 590 feet, providing a storage capacity of 1,016 acre-feet. The dam is regulated and inspected by the Iowa Department of Natural Resources, with a satisfactory condition assessment as of July 2020.
With a high hazard potential, the North Branch Ralston Creek Dam serves as a critical infrastructure for managing water resources in the area. The dam is equipped with an uncontrolled spillway and is designed to mitigate flooding events to protect downstream communities. The risk assessment for the dam is moderate, indicating a need for ongoing monitoring and management to ensure its effectiveness in flood control.
As climate change continues to pose challenges to water resource management, the North Branch Ralston Creek Dam plays a vital role in safeguarding the local community from potential hazards. With regular inspections and a solid emergency action plan, the dam stands ready to address any unforeseen events and maintain its role in flood risk reduction. As water resource and climate enthusiasts, it is crucial to acknowledge the importance of such infrastructure in adapting to a changing climate and ensuring the resilience of our communities.
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 North Branch Ralston Creek Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Iowa River At Iowa City | 2,160 cfs | → |
| Rapid Creek Near Iowa City | 10 cfs | → |
| Iowa River Below Coralville Dam Nr Coralville | 2,140 cfs | → |
| Clear Creek Near Coralville | 29 cfs | → |
| Old Mans Creek Near Iowa City | 118 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 North Branch Ralston Creek Dam.
Boat launches
- Mehaffey Bridge Road Northeast , 52333 Iowa
- 520th Street Southeast Johnson County
- Falcon Lane Big Grove Township
- Cottage Reserve Road Northeast Big Grove Township
- Anglers Point Road Northeast Big Grove Township
- Poplar Avenue Northeast Big Grove Township
Track North Branch Ralston Creek 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 North Branch Ralston Creek Dam
Where does the data for North Branch Ralston Creek 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 North Branch Ralston Creek Dam.