Macallen Dam dam
Macallen Dam
Located in Newmarket, New Hampshire, the Macallen Dam stands as a testament to the engineering ingenuity of its time, having been completed in 1887. This concrete buttress dam spans 150 feet in length and reaches a height of 27 feet, providing a storage capacity of 1740 acre-feet along the Lamprey River. With a primary purpose of recreation, the dam offers a surface area of 120 acres for water enthusiasts to enjoy various activities.
Despite its historical significance and recreational value, the Macallen Dam poses a high hazard potential and has been assessed as being in poor condition as of June 2016. Regular inspections are conducted, with the latest one taking place in September 2020, to ensure the safety of the surrounding communities. While the risk assessment deems the dam to have a moderate risk level, there is ongoing monitoring and management measures in place to safeguard against potential emergencies and mitigate any risks associated with its operation.
Managed by the local government and regulated by the NHDES Dam Bureau, the Macallen Dam not only serves as a recreational hub but also plays a crucial role in water resource management and climate resilience efforts in the region. As water resource and climate enthusiasts, it is important to stay informed about the state of infrastructure like the Macallen Dam to support sustainable practices and ensure the preservation of vital water resources for future generations.
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 Macallen Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Lamprey River Near Newmarket | 137 cfs | → |
| Oyster River Near Durham | 13 cfs | → |
| Winnicut River At Greenland | 22 cfs | → |
| Exeter River At Haigh Road | 57 cfs | → |
| Isinglass R At Rochester Neck Rd | 66 cfs | → |
| Cocheco River Near Rochester | 117 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Macallen Dam.
Boat launches
- Lamprey River Boat Launch
- Piscassic River Boat Launch
- Squamscott River Boat Launch
- Great Bay Boat Launch
- Oyster River Boat Launch
Campgrounds
- Old Stage Campground
- Remote Campsite
- Tidewater Campground
- Saddleback Campground
- Salisbury State Park Reservation
- Windham Town Forest Tent Platforms
Paddle runs
Track Macallen 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 Macallen Dam
Where does the data for Macallen 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 High 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 Macallen Dam.