recent changes

2013-06-19: The vertical datum of the 1998 TWDB rating curve for Lake Graham has been adjusted from NGVD29 to NGVD29+1.3ft.

Lake Graham is 100.0% full as of 2016-09-27

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, while 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.

Date Percent Full Mean Water Level
(ft)
Reservoir Storage
(acre-ft)
Conservation Storage
(acre-ft)
Conservation Capacity
(acre-ft)
Surface Area
(acres)
Most recent 2016-09-27 100.0 1,075.15 45,674 45,288 45,288 - n.a. -
1 day prior 2016-09-26 100.0 1,075.14 45,650 45,288 45,288 - n.a. -
2 days prior 2016-09-25 99.9 1,074.98 45,253 45,239 45,288 2,442
1 week prior 2016-09-20 99.2 1,074.86 44,957 44,943 45,288 2,434
1 month prior 2016-08-27 100.0 1,075.35 46,173 45,288 45,288 - n.a. -
3 months prior 2016-06-27 99.2 1,074.86 44,957 44,943 45,288 2,434
6 months prior 2016-03-27 98.9 1,074.80 44,809 44,795 45,288 2,430
1 year prior 2015-09-27 88.5 1,072.83 40,094 40,080 45,288 2,295
*

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 2016-09-28 03:00 1,075.13 1,075.0 0.1 into flood pool
1 hour prior 2016-09-28 02:00 1,075.13 1,075.0 0.1 into flood pool
2 hours prior 2016-09-28 01:00 1,075.13 1,075.0 0.1 into flood pool
6 hours prior 2016-09-27 21:00 1,075.14 1,075.0 0.1 into flood pool
12 hours prior 2016-09-27 15:00 1,075.15 1,075.0 0.2 into flood pool
24 hours prior 2016-09-27 03:00 1,075.15 1,075.0 0.2 into flood pool
48 hours prior 2016-09-26 03:00 1,075.10 1,075.0 0.1 into flood pool
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1958-01-01
Vertical datum NGVD29 +1.3
Gauge USGS:08088400
Dead pool elevation 1030.0 ft above NGVD29 +1.3
Service spillway crest elevation 1076.3 ft above NGVD29
Conservation pool elevation 1075.0 ft above NGVD29 +1.3
Top of dam elevation 1093.3 ft above NGVD29
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1958-01-01 (source: usgs)
1998-04-01 (source: twdb) : GIS Data