Gilliand Dam dam
Gilliand Dam
Gilliand Dam, located in Washington County, Iowa, stands as a testament to effective water resource management and climate adaptation efforts. Built in 1972 by the USDA NRCS, this earth dam serves multiple purposes including fire protection and creating a small fish pond. With a height of 32 feet and a length of 352 feet, the dam has a storage capacity of 41 acre-feet, providing crucial water resources for the surrounding area.
Managed by a private owner and regulated by the Iowa DNR, Gilliand Dam has been deemed to have a low hazard potential and a moderate risk assessment rating. Despite not being currently rated for condition assessment, the dam continues to play a vital role in water conservation and ecosystem preservation along the TR-GOOSE CREEK river system. While the dam does not have outlet gates or a controlled spillway, its uncontrolled spillway type ensures that excess water is safely managed during heavy rainfall events.
As climate change continues to pose challenges to water resources and infrastructure, Gilliand Dam stands as a reliable structure in safeguarding against potential risks. With its strategic location and design, the dam remains a valuable asset in maintaining water security and supporting the local ecosystem. Adhering to state regulations and undergoing regular inspections, Gilliand Dam exemplifies the importance of sustainable water management practices in the face of a changing climate.
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 Gilliand Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Iowa River Near Lone Tree | 3,230 cfs | → |
| English River At Kalona | 228 cfs | → |
| Cedar River Near Conesville | 6,160 cfs | → |
| Old Mans Creek Near Iowa City | 118 cfs | → |
| Iowa River At Iowa City | 2,160 cfs | → |
| Clear Creek Near Coralville | 29 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Gilliand Dam.
Boat launches
- Vine Avenue Washington County
- Riverside Road Riverside
- Sand Road Southeast Johnson County
- 520th Street Southeast Johnson County
- Dogwood Avenue Washington County
- W15 / 330th Avenue Keokuk County
Campgrounds
- Marr Park
- River Junction Access
- Crooked Creek Christian Camp
- Hills Access
- Louisa County Fairgrounds
- Brinton Timber
More reservoirs
Track Gilliand 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 Gilliand Dam
Where does the data for Gilliand 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 Gilliand Dam.