Occum dam
Occum
Occum, located in Norwich, Connecticut, is a masonry dam on the Shetucket River primarily used for hydroelectric purposes. Built in 1900, this dam stands at 14 feet high and spans 520 feet in length, with a storage capacity of 155 acre-feet and a surface area of 65 acres. The dam is regulated by the Federal Energy Regulatory Commission and has a low hazard potential, with a moderate risk assessment rating.
Despite not being state-regulated or inspected, Occum has a history of regular maintenance and emergency preparedness, with an updated Emergency Action Plan in place as of December 2020. The dam's spillway is uncontrolled and has a width of 450 feet, serving as a safety feature in case of high water levels. With a risk assessment rating of moderate, Occum is closely monitored to ensure the safety and integrity of the structure for both water resource and climate enthusiasts in the area.
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 Occum -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Shetucket River At Taftville | 1,070 cfs | → |
| Quinebaug River At Jewett City | 1,010 cfs | → |
| Yantic River At Yantic | 101 cfs | → |
| Little River Near Hanover | 42 cfs | → |
| Shetucket River Near Willimantic | 736 cfs | → |
| Natchaug River At Willimantic | 348 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Occum .
Boat launches
- Butts Bridge Road Canterbury
- Jerusalem Road South Windham
- Jeffrey Lane Griswold
- Amos Lake
- Lovell Lane 50, Canterbury
- Glasgo Pond State Boat Launch
Campgrounds
- Highland Campground
- Laurel Lock Camp
- Mystic Koa Holiday
- Youth Site 1
- Youth Site 2
- Dyer Woods Nudist Campgrounds
Fishing spots
Paddle runs
- Begins Below The Tailrace Of The Rainbow Dam To The Confluence With The Connecticut River
- The Confluence Of The East And West Branches To The Confluence With The Farmington River In East Granby
- Begins Below The Tailrace Of The Lower Collinsville Dam To The Route 187 Bridge
- The Confluence With The Nepaug River To A Point 0.2 Miles Below The Lower Collinsville Dam Tailrace
- New Hartford/Canton Town Line To The Confluence With The Nepaug River
- The Massachusetts-Connecticut State Line In Hartland To The Confluence With The Salmon Brook Main Stem
Track Occum 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 Occum
Where does the data for Occum 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 Occum .