Monticello Reservoir: 81.7% full as of 2025-08-20

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)
Today 2025-08-20 81.7 336.63 28,373 28,373 34,740 1,696
Yesterday 2025-08-19 81.6 336.62 28,355 28,355 34,740 1,695
2 days ago 2025-08-18 81.8 336.65 28,407 28,407 34,740 1,698
1 week ago 2025-08-13 82.2 336.73 28,547 28,547 34,740 1,705
1 month ago 2025-07-20 84.6 337.20 29,377 29,377 34,740 1,748
3 months ago 2025-05-20 86.6 337.59 30,082 30,082 34,740 1,783
6 months ago 2025-02-20 87.1 337.69 30,264 30,264 34,740 1,792
1 year ago 2024-08-20 84.7 337.23 29,431 29,431 34,740 1,750
*

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 2025-08-20 21:15 336.67 340.00 -3.33
1 hour prior 2025-08-20 20:15 336.67 340.00 -3.33
2 hours prior 2025-08-20 19:15 336.67 340.00 -3.33
6 hours prior 2025-08-20 15:15 336.66 340.00 -3.34
12 hours prior 2025-08-20 09:15 336.63 340.00 -3.37
24 hours prior 2025-08-19 21:15 336.62 340.00 -3.38
48 hours prior 2025-08-18 21:15 336.64 340.00 -3.36
*

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

Lake Location