John Martin Reservoir is managed by U.S. Army Corps of Engineers; Colorado Parks and Wildlife (state park recreation). Lake Insights displays its latest available elevation from U.S. Geological Survey (USGS). Published reference elevations are listed below.
Lake Status
50.88 feet below full pool
−50.88 ft vs full pool
- 7-day trend
- Falling
- 7-day change
- Down 0.12 ft
- 30-day change
- Down 0.57 ft
- Last updated
- 59 minutes ago
John Martin Reservoir is currently 50.88 feet below full pool and has fallen slightly over the past week. Readings show continued drawdown relative to full pool, with levels trending lower over the past week.
Watershed drought conditions
Bent County, CO · surrounding county from lake location
Moderate Drought
Moderate drought is affecting the watershed.
Severity
Weekly trend
Improving
Compared with last week
Official drought
Yes
100% of the watershed is currently classified as official drought (D1+).
Expected impacts
- Stream inflows may run below normal
- Lake levels can decline faster between rain events
- Vegetation stress may increase over time
U.S. Drought Monitor · map date Sep 15, 2026. Updated weekly. droughtmonitor.unl.eduView drought map for Bent County, CO
Key Facts
Waterbody / project type
Official purposes
Full pool
Flood stage
Current-level source
Project / NID identifier
Dam / watershed (NID design values)
Static design values from a confidently matched National Inventory of Dams record — not live gage readings.
- Normal storage
- 567 acre-ft
- Max storage
- 860 acre-ft
- Surface area at normal pool
- 45 acres
- Spillway capacity (design)
- 425 cfs
- Dam structure
- Earth · 23 ft high · completed 1974
- Hazard classification
- High
- Safety & inspection
- Fair · last inspection Jul 7, 2022
National Inventory of Dams · matched record: Weir and Johnson (CO00643)
How this lake is operated
- Documented project purposes (National Inventory of Dams): Recreation, Irrigation.
Why the level can change
General factors for reservoirs like this
These are common influences for this type of lake. They do not identify the cause of a specific current change unless an operator update confirms it.
Rainfall & inflows
Rain and upstream river inflows can raise reservoir levels, especially after storms.
Downstream releases
When an operator releases water through a dam, reservoir storage can fall and downstream flows can rise.
Flood-risk operations
Some projects store or release water under flood-risk rules when conditions require it.
Water supply
Some reservoirs support municipal, industrial, irrigation, or regional water-supply needs.
Hydropower
Hydropower projects may pass water through turbines when generating electricity.
Seasonal weather
Dry periods, heat, evaporation, and seasonal rainfall patterns can affect storage over weeks and months.
Published reference elevations
- Full pool
- 3852.00 ft
- Flood stage
- 3880.00 ft
Published reference elevation. Not necessarily a fixed year-round target for every project.
Flood stage is not interchangeable with flood pool.
Current data source
Managing authority: U.S. Army Corps of Engineers; Colorado Parks and Wildlife (state park recreation)
Observation source used by Lake Insights: U.S. Geological Survey (USGS)
Who manages the lake and who publishes the reading Lake Insights displays can differ. Lake Insights does not invent a source label from the managing authority alone.
General education
Shared background — not lake-specific facts
Lake Insights aggregates water level information from authoritative public sources such as the U.S. Army Corps of Engineers, NOAA, TVA, Bureau of Reclamation, power utilities, and other official lake operators. We preserve historical observations, calculate trends, and present lake conditions in a consistent format. For U.S. Geological Survey (USGS), we link to the official source whenever it is available. Lake Insights does not predict future lake levels unless an official forecast has been published by the managing authority.
Common questions about John Martin Reservoir
- Who manages John Martin Reservoir?
- John Martin Reservoir is managed by U.S. Army Corps of Engineers; Colorado Parks and Wildlife (state park recreation). Lake Insights reports published gauge readings; it does not operate the waterbody.
- What is full pool at John Martin Reservoir?
- The published full-pool elevation for John Martin Reservoir is 3852.00 ft. Full pool is a published reference elevation — not a prediction of today’s level.
- Where does Lake Insights get the level reading for John Martin Reservoir?
- Lake Insights displays the latest available elevation for John Martin Reservoir from U.S. Geological Survey (USGS). The managing authority (U.S. Army Corps of Engineers; Colorado Parks and Wildlife (state park recreation)) may differ from the agency that publishes the observation used on this page.
- What are the documented purposes of John Martin Reservoir?
- Documented purposes for John Martin Reservoir (National Inventory of Dams): Recreation, Irrigation.