Arnold Falls dam
Arnold Falls
Arnold Falls, also known as Tsg&E No. 1 1/2, is a hydroelectric dam located in St. Johnsbury, Vermont, along the Passumpsic River. This timber crib dam stands at a height of 21 feet and has a length of 285 feet, with a storage capacity of 170 acre-feet. The dam serves a primary purpose of generating hydroelectric power and is owned by a public utility in Vermont.
Despite being a low hazard potential structure with a "Not Rated" condition assessment, Arnold Falls has not been inspected since May 2000. The dam, which is under state jurisdiction, does not currently have state permitting or inspection requirements. However, with a drainage area of 245 square miles and a surface area of 7 acres, it plays a crucial role in managing water resources in Caledonia County and Vermont.
For water resource and climate enthusiasts, Arnold Falls represents a unique opportunity to explore the intersection of renewable energy generation and dam infrastructure in rural New England. With its location in a picturesque setting along the Passumpsic River and its historical significance in harnessing hydropower, Arnold Falls offers a fascinating case study in sustainable water management practices and the challenges of maintaining aging infrastructure in the face of changing climate 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 Arnold Falls -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Sleepers River (Site W-5) Near St. Johnsbury | 87 cfs | → |
| Passumpsic River At Passumpsic | 942 cfs | → |
| Pope Brook (Site W-3) Nr. N. Danville | 8 cfs | → |
| Moose River At Victory | 164 cfs | → |
| Connecticut River Near Dalton | 3,330 cfs | → |
| East Branch Passumpsic River Near East Haven | 128 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Arnold Falls.
Boat launches
- Shadow Lake Road Concord
- Harveys Hollow Road Peacham
- Taylor Road Peacham
- Partridge Lake Boat Launch
- Old Waterford Road Littleton
- Perkins Landing Road Littleton
Campgrounds
- Sugar Ridge Rv Resort
- Crazy Horse Family Campground
- Burke Mountain Campground
- Boy Scout's Of America
- New Discovery State Park
- Big Deer State Park
Paddle runs
- Headwaters At Profile Lake To Southern Boundary Of Franconia Notch State Park
- Woodstock/Thornton Town Line To Thornton Railroad Bridge
- Thornton Railroad Bridge To Bridgewater/Bristol Town Line
- Headwaters To Folsom Brook
- Proclamation Boundary To Proclamation Boundary
Track Arnold Falls 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 Arnold Falls
Where does the data for Arnold Falls 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 Arnold Falls.