Swamp Locks dam
Swamp Locks
Swamp Locks, also known as Upper Pawtucket Canal Dam, is a private hydroelectric structure located in Lowell, Massachusetts. Built in 1823, this concrete gravity dam stands at a height of 15 feet and has a length of 105 feet. With a storage capacity of 4500 acre-feet and a surface area of 720 acres, the dam serves multiple purposes including fire protection, flood risk reduction, and recreation.
Managed by the Federal Energy Regulatory Commission, Swamp Locks has a controlled spillway with a width of 80 feet. Despite its low hazard potential, the dam is considered to have a very high risk due to its age and lack of condition assessment. The last inspection in May 2019 revealed that the condition assessment was not available, highlighting the need for further evaluation and potential risk management measures.
Although Swamp Locks does not have associated locks, it is one of 15 structures in the area that contribute to the operation and function of the dam. As climate and water resource enthusiasts explore the historical and ecological significance of this dam, its location within the Upper Pawtucket Canal and its role in the local ecosystem provide valuable insights into the intersection of human infrastructure and natural water systems in the region.
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 Swamp Locks -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Concord R Below R Meadow Brook | 311 cfs | → |
| Merrimack River Bl Concord River At Lowell | 11,800 cfs | → |
| Shawsheen River Near Wilmington | 21 cfs | → |
| Spicket River Near Methuen | 25 cfs | → |
| Beaver Brook At North Pelham | 35 cfs | → |
| Nashoba Brook Near Acton | 7 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Swamp Locks .
Boat launches
- Billerica Street 5-65, Lowell
- Pawtucket Boulevard 936-970, Lowell
- Willowdale Avenue 1-53, Dracut
- Flint Pond Road, Tyngsborough
- Farm Road, Billerica
- Methuen Riverside Boat Ramp
Track Swamp Locks 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 Swamp Locks
Where does the data for Swamp Locks 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 Swamp Locks .