Lower Lake Mary dam
Lower Lake Mary
Lower Lake Mary, located in Coconino, Arizona, is a federal water supply reservoir managed by the USDA Forest Service. Built in 1907, this earth dam structure stands at 33 feet high with a storage capacity of 22,400 acre-feet and a surface area of 910 acres. The reservoir primarily serves as a water supply source but also supports fish and wildlife habitats, recreation activities, and flood control along Walnut Canyon.
With a high hazard potential, Lower Lake Mary has a moderate risk rating, indicating a need for ongoing monitoring and management. The dam features an uncontrolled spillway and a spillway width of 75 feet to manage maximum discharge levels of up to 3,298 cubic feet per second. Despite its condition being currently unrated, the reservoir's inspection frequency of one year suggests regular assessments to ensure the safety and functionality of the structure. For water resource and climate enthusiasts, Lower Lake Mary offers a fascinating case study of a historic dam supporting multiple purposes in a scenic natural setting within the Walnut Canyon area.
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 Lower Lake Mary -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Oak Creek Near Sedona | 28 cfs | → |
| Dry Beaver Creek Near Rimrock | · | → |
| Oak Creek Near Cornville | 23 cfs | → |
| Wet Beaver Creek Near Rimrock | 8 cfs | → |
| Verde River Near Clarkdale | 58 cfs | → |
| West Clear Creek Near Camp Verde | 15 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lower Lake Mary.
Campgrounds
- Canyon Vista
- Canyon Vista Campground
- Marshall Lake Dispersed Camping
- Lakeview Campground
- Black Barts Rv Park
- Fort Tuthill Military - Luke Afb
Fishing spots
Paddle runs
- Sterling Springs Fish Hatchery To Private Land In Sec 5, T17n,R6e
- Headwaters In Sec 14, T19n, R5e To Confluence With Oak Creek
- Indian Gardens
- Parsons Spring To Confluence Of The Verde River
- Headwaters In Sec 16, T15n, R8e To Wet Beaver Creek Wilderness Boundary
- Wet Beaver Creek Wilderness Boundary To Private Land In Sec 32, T15n, R6e
Track Lower Lake Mary 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 Lower Lake Mary
Where does the data for Lower Lake Mary 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 Lower Lake Mary.