Dam Report

H-1 Pool Dam dam

Michigan, USA Grays Creek-Offstream Hazard Low
Today high
--
Tonight low
--
Dam height
8ft
Hazard rating
Low
Loading current conditions…
Loading next 24 hours…
Loading 7-day outlook…
H-1 Pool Dam -- None dam
H-1 Pool Dam None · Grays Creek-Offstream
About this dam

H-1 Pool Dam

The H-1 Pool Dam in Manistique, Michigan, stands as a vital water resource infrastructure managed by federal authorities. Completed in 1937, this earth dam spans a length of 7260 feet and reaches a height of 8 feet, providing crucial storage of up to 384 acre-feet of water for various purposes. Situated on Grays Creek-Offstream, the dam's controlled spillway with a width of 92 feet ensures efficient water discharge during peak flows, contributing to flood control efforts in the region.

Despite its significance, the H-1 Pool Dam exhibits signs of wear and tear, with a poor condition assessment noted during the last inspection in July 2018. Recognized as having a low hazard potential but a very high risk level, the dam requires attention to ensure its long-term safety and functionality. With the Michigan Department of Environment, Great Lakes, and Energy overseeing state regulatory aspects, ongoing inspections and risk management measures are crucial to safeguarding this critical infrastructure and the surrounding community.

As a key component of water resource management in Schoolcraft County, the H-1 Pool Dam serves as a reminder of the importance of proactive maintenance and risk assessment in maintaining the integrity of our water infrastructure. With its historical significance and essential role in flood control, efforts to address its condition and mitigate risks are essential for ensuring the continued protection of downstream communities and the environment.

StateNone
River / streamGrays Creek-Offstream
NID IDMI00633
Owner typeFederal
Primary purposeOther
Dam typeEarth
Year built1937
Dam height8 ft
Dam length7,260 ft
Max storage384 AF
Normal storage240 AF
Surface area120.0 ac
Hazard potentialLow
ConditionPoor
Last inspectionTue, 17 Jul 2018 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 H-1 Pool Dam -- inflows here typically show up in storage 24-72 hours later.

Track H-1 Pool 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.

FAQ

About H-1 Pool Dam

Where does the data for H-1 Pool 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 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.

More reservoirs

Other water bodies near here

Snoflo-tracked reservoirs and dams within driving distance of H-1 Pool Dam.