Somerville Lake: 96.2% full as of 2025-09-14

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 2025-09-14 96.2 237.49 144,614 144,614 150,293 11,004
1 day prior 2025-09-13 96.3 237.50 144,723 144,723 150,293 11,009
2 days prior 2025-09-12 96.4 237.52 144,944 144,944 150,293 11,018
1 week prior 2025-09-07 97.1 237.61 145,938 145,938 150,293 11,062
1 month prior 2025-08-14 99.8 237.98 150,067 150,067 150,293 11,360
3 months prior 2025-06-14 100.0 239.01 161,914 150,293 150,293 - n.a. -
6 months prior 2025-03-14 85.6 236.00 128,670 128,670 150,293 10,436
1 year prior 2024-09-14 98.9 237.85 148,608 148,608 150,293 11,190
*

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 2025-09-14 23:00 237.47 238.00 -0.53 below flood pool
1 hour prior 2025-09-14 22:00 237.47 238.00 -0.53 below flood pool
2 hours prior 2025-09-14 21:00 237.48 238.00 -0.52 below flood pool
6 hours prior 2025-09-14 17:00 237.47 238.00 -0.53 below flood pool
12 hours prior 2025-09-14 11:00 237.48 238.00 -0.52 below flood pool
24 hours prior 2025-09-13 23:00 237.50 238.00 -0.50 below flood pool
48 hours prior 2025-09-12 23:00 237.51 238.00 -0.49 below flood pool
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1967-01-01
Vertical datum NGVD29
Dead pool elevation 206.00 ft above NGVD29
Emergency spillway crest elevation 258.00 ft above NGVD29
Flood pool elevation 258.00 ft above NGVD29
Maximum design elevation 274.50 ft above NGVD29
Top of dam elevation 280.00 ft above NGVD29
Conservation pool elevation 238.00 ft above NGVD29
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1967-01-01 (source: USGS)
2003-07-01 (source: TWDB) : GIS Data
2012-04-01 (source: TWDB) : GIS Data
Data Source USGS:08109900

Lake Location