Dam Report

Antietam dam

Pennsylvania, USA East Branch Antietam Creek Hazard High
Today high
--
Tonight low
--
Dam height
70ft
Hazard rating
High
Loading current conditions…
Loading next 24 hours…
Loading 7-day outlook…
Antietam -- None dam
Antietam None · East Branch Antietam Creek
About this dam

Antietam

Antietam is a vital Earth dam located in Hamiltonban Township, Pennsylvania, serving as a crucial water supply source for the area. Completed in 1953, the dam stands at a height of 70 feet and has a capacity of 866 acre-feet, with a normal storage level of 464 acre-feet. With a surface area of 27 acres and a drainage area of 3.9 square miles, the dam plays a significant role in managing water resources for the region.

Owned and regulated by the Pennsylvania Department of Environmental Protection, Antietam is subject to regular inspections and enforcement to ensure its structural integrity and operational efficiency. Classified with a high hazard potential and assessed to be in fair condition, the dam is monitored closely to mitigate any potential risks and ensure the safety of surrounding communities. Despite its age, Antietam continues to serve its primary purpose of water supply effectively, highlighting the importance of proper maintenance and regulation in safeguarding critical infrastructure in the face of changing climate conditions.

As water resource and climate enthusiasts, understanding the significance of dams like Antietam in managing water supply and mitigating risks is crucial. The dam's location along the East Branch Antietam Creek, in Adams County, Pennsylvania, underscores the interconnectedness of water resources and the environment. With ongoing monitoring and regulatory oversight, Antietam stands as a testament to the importance of sustainable water management practices in the face of evolving climate challenges.

StateNone
River / streamEast Branch Antietam Creek
NID IDPA00332
Owner typeLocal Government
Primary purposeWater Supply
Dam typeEarth
Year built1953
Dam height70 ft
Dam length815 ft
Max storage866 AF
Normal storage464 AF
Surface area27.0 ac
Drainage area3.9 sq mi
Hazard potentialHigh
ConditionFair
Last inspectionWed, 09 Dec 2020 00:00:00 GMT

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.
Detailed forecast

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.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

Loading hourly forecast…
Deep dive

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.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
Loading detailed forecast…
Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

Loading 15-day outlook…
Regional inflow

Nearby streamflow gauges

USGS streamgauges around Antietam -- inflows here typically show up in storage 24-72 hours later.

Track Antietam 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.

FAQ

About Antietam

Where does the data for Antietam 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.

More reservoirs

Other water bodies near here

Snoflo-tracked reservoirs and dams within driving distance of Antietam.

Premium feature

Favorites and alerts are part of Snoflo Premium. Save reservoirs, set storage thresholds, and get push notifications when conditions cross.

Upgrade to Premium Not now
🔔

Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this dam, set a threshold, and you'll get a push the moment conditions cross.

Open App Store