Lake Sumner Reservoir
As of September 12, 2026, Lake Sumner is holding 3,222 acre-ft of water — 13% of normal storage for this date. Storage data refreshed throughout the day.
Lake Sumner
Lake Sumner is a reservoir located in the eastern part of New Mexico, United States. The lake was formed in the 1930s by the construction of a dam on the Pecos River. It is primarily fed by the Pecos River and its tributaries, as well as by snowmelt from the nearby mountains. The lake serves as a source of irrigation water for agricultural purposes and is also used for recreational activities such as fishing, boating, and camping. The surrounding area is home to several species of wildlife, including deer, elk, and pronghorn antelope. In recent years, the lake has faced challenges from drought and overuse, leading to concerns about its long-term sustainability. Efforts are underway to address these issues through improved water management and conservation measures.
Daily levels at Lake Sumner
Storage volume, pool elevation, and total release plotted from the operating agency's daily observations.
Storage
acre-ft · code 17
Inflow
cfs · code 29
Pool Elevation
ft · code 49
Total Release
cfs · code 42
Inside the reservoir
The real shoreline of this water body, with a depth model scaled so the basin holds exactly its recorded storage. Drag to orbit, scroll to zoom, and use the slider to drain and refill it. Click anywhere on the basin for the modelled depth there.
How this is built. The shoreline is the National Hydrography
Dataset polygon for this water body,
matched to the dam by proximity and confirmed by comparing its area with the
National Inventory of Dams surface area.
Depth is modelled, not surveyed: the basin is shaped by distance from
shore — deep in open water, shallow in the bays — and scaled so its
volume equals the recorded storage. No national bathymetric survey exists for
US reservoirs. Treat the shoreline, area and volume as measured, and the depth
distribution as an informed approximation.
Above normal pool, water is shown rising within the normal-pool
shoreline. Where it would actually spread depends on the surrounding
terrain, which is not modelled here — a reservoir in a steep canyon barely
widens, one on flat ground can spread a long way. This is a depth and volume
figure, not an inundation map. Official inundation mapping for a dam
comes from its Emergency Action Plan.
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 Lake Sumner -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Pecos River Below Sumner Dam | 90 cfs | → |
| Pecos River Near Puerto De Luna | 58 cfs | → |
| Fort Sumner Main Canal Near Fort Sumner | 70 cfs | → |
| Pecos River Below Taiban Creek Near Fort Sumner | 20 cfs | → |
| Pecos River Below Santa Rosa Dam | 2 cfs | → |
| Pecos River Above Santa Rosa Lake | 3 cfs | → |
About Lake Sumner
What is the water level at Lake Sumner Reservoir right now?
As of September 12, 2026, Lake Sumner Reservoir is holding 3,222 acre-ft, about 13% of normal for this date. Pool elevation and the year-over-year trend are shown above.
Is Lake Sumner Reservoir high or low right now?
Compare the percent-of-normal figure on this page: above 100% means storage is higher than the historical average for the date (a wet year), below 100% means lower (a dry year or drought). The daily-levels chart shows the current trend.
Where does the data for Lake Sumner come from?
Daily storage, pool elevation, and release rates are sourced from USGS, USBR, and USACE monitoring stations. Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
Storage observations are updated daily by the operating agency. The 15-day weather forecast refreshes throughout the day. Snoflo caches and renders the most recent observation -- check the "as of" timestamp on the storage card.
What does the Hazard 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 below 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 reservoir, set a threshold, and you'll get a push the moment conditions cross.
Create a free account, or sign in.
Get the free Lake Sumner report — alerts, favorites, and history & forecasts, plus the free iPhone app.