Reservoir · Colorado · United States · USACE CWMS
John Martin Reservoir
9.2% full
Capacity
425.86 hm³
Volume stored
39 hm³
Vs month average
174% of normal
Coordinates
38.067°N, 102.937°W
Last updated
2026-10-14
Current fill
9.2%vs 7 days ago
+0.2%gaining
vs 1 year ago
+4.0%year-over-year
7-day trend
→stable
Drought context
Storage vs October average
174%of normal
9.2% full on 2026-10-14, against an average of 5.3% for October across 6 years of readings (+3.9 points).
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Capacity is the design (normal full-pool) capacity from the US National Inventory of Dams (NID); fill % = current volume ÷ design capacity. Last reading: 2026-10-14.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 38.067, -102.937 · Open in Google Maps
About John Martin Reservoir
As of October 14, 2026, John Martin Reservoir is filled to 9.2% of its total capacity, holding roughly 39 hm³ of water out of a maximum 426 hm³. At this level the reservoir is critically low.
Over the most recent week on record the fill level has held broadly steady (+0.2 pts), and it is 4.0 points above its level on the same date a year earlier.
Across the readings we hold for John Martin Reservoir — 1825 data points between October 16, 2021 and October 14, 2026 — the level has ranged from a low of 3.3% (October 9, 2022) to a high of 30.0% (July 24, 2023). On average the reservoir is fullest around April and at its lowest around October.
It is operated by USACE primarily for multiple purposes. It lies within the Colorado basin at 38.067°N, 102.937°W.
Key facts
- Current fill level
- 9.2%
- Water stored
- 39 hm³
- Total capacity
- 426 hm³
- 7-day change
- ▲ 0.2 pts
- Year-on-year
- ▲ 4.0 pts
- Primary use
- Multipurpose
- River basin
- Colorado
- Operator
- USACE
- Coordinates
- 38.067°N, 102.937°W
- Last updated
- October 14, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 14 Oct 2026 | 9.2% | 39 |
| 13 Oct 2026 | 9.3% | 39 |
| 12 Oct 2026 | 9.2% | 39 |
| 11 Oct 2026 | 9.2% | 39 |
| 10 Oct 2026 | 9.2% | 39 |
| 9 Oct 2026 | 9.2% | 39 |
| 8 Oct 2026 | 9.1% | 39 |
| 7 Oct 2026 | 9.0% | 38 |
| 6 Oct 2026 | 8.9% | 38 |
| 5 Oct 2026 | 8.7% | 37 |
| 4 Oct 2026 | 8.1% | 35 |
| 3 Oct 2026 | 7.3% | 31 |