Maquoketa Milldam dam
Maquoketa Milldam
Maquoketa Milldam, located in Maquoketa, Iowa, is a historic gravity dam completed in 1923 for hydroelectric power generation and recreation purposes. The dam, standing at 26 feet tall and spanning 700 feet in length, harnesses the Maquoketa River's flow to store up to 4,419 acre-feet of water for various uses. With a surface area of 340 acres and serving a drainage area of 953 acres, the dam's controlled spillway type ensures proper water management while maintaining a low hazard potential.
Managed by the Iowa Department of Natural Resources, Maquoketa Milldam has been deemed in satisfactory condition as of the latest assessment in 2016, with a very high risk rating due to its age and potential impact on the surrounding area. Despite its historical significance and recreational value, the dam has not undergone any major modifications in recent years, with the last inspection conducted in 2007. As a key structure in the region's water resource management, Maquoketa Milldam serves as a reminder of the intersection between nature, infrastructure, and climate resilience in the face of changing environmental conditions.
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 Maquoketa Milldam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Maquoketa River Near Maquoketa | 1,340 cfs | → |
| North Fork Maquoketa River Near Fulton | 420 cfs | → |
| Wapsipinicon River Near De Witt | 1,710 cfs | → |
| Apple River Near Hanover | 121 cfs | → |
| Wapsipinicon River Near Anamosa | 967 cfs | → |
| Sinsinawa River Near Menominee | 22 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Maquoketa Milldam.
Boat launches
- North 5th Street 500, Maquoketa
- Ansel Briggs Highway Jackson County
- 60th Avenue 17158, Jackson County
- 235th Street 1486, Clinton County
- Great River Road Jackson County
Track Maquoketa Milldam 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 Maquoketa Milldam
Where does the data for Maquoketa Milldam 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 Maquoketa Milldam.