Monticello Reservoir: 80.5% full as of 2026-04-20

The elevation-storage rating curve used to produce the storage hydrograph is made of two segments: (1) the segment up to the conservation pool top (below the red line) is based on measured data, and (2) the segment in the flood pool (above the red line) is an extrapolation from the first segment and shouldn't be relied upon for flood storage information.

Historical Data

Date Percent Full Mean Water Level
(ft)
Reservoir Storage
(acre-ft)
Conservation Storage
(acre-ft)
Conservation Capacity
(acre-ft)
Surface Area
(acres)
Most recent 2026-04-20 80.5 336.39 27,958 27,958 34,740 1,674
1 day prior 2026-04-19 80.4 336.38 27,941 27,941 34,740 1,673
2 days prior 2026-04-18 80.2 336.34 27,873 27,873 34,740 1,670
1 week prior 2026-04-13 80.2 336.34 27,873 27,873 34,740 1,670
1 month prior 2026-03-20 78.8 336.05 27,381 27,381 34,740 1,644
3 months prior 2026-01-20 77.9 335.86 27,062 27,062 34,740 1,627
6 months prior 2025-10-20 79.3 336.16 27,566 27,566 34,740 1,654
1 year prior 2025-04-20 86.3 337.53 29,972 29,972 34,740 1,778
*

Percent Full is based on Conservation Storage and Conservation Capacity and doesn't account for storage in flood pool.

**

   Values above, including today's are averaged conditions. For near real-time instantaneous water level, see table below or the interactive map viewer.

Most Recent Instantaneous Water Level

Date/time Water Level
(ft)
Conservation Pool Elevation
(ft)
Height Above Conservation Pool
(ft)
Most recent 2026-04-20 15:15 336.39 340.00 -3.61
1 hour prior 2026-04-20 14:15 336.39 340.00 -3.61
2 hours prior 2026-04-20 13:15 336.38 340.00 -3.62
6 hours prior 2026-04-20 09:15 336.39 340.00 -3.61
12 hours prior 2026-04-20 03:15 336.39 340.00 -3.61
24 hours prior 2026-04-19 15:15 336.36 340.00 -3.64
48 hours prior 2026-04-18 15:15 336.35 340.00 -3.65
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1973-01-01
Vertical datum NGVD29
Service spillway crest elevation 328.00 ft above NGVD29
Emergency spillway crest elevation 343.50 ft above NGVD29
Top of dam elevation 352.00 ft above NGVD29
Conservation pool elevation 340.00 ft above NGVD29
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1998-02-01 (source: TWDB) : GIS Data
Data Source USGS:07344488
USGS Monitoring Location USGS:07344488

Lake Location