I wanted to leave a documentation of some of the spring flooding. Many weather records have been established the first half of this year. We had some record snow falls in February. Several large tornado outbreaks in the first half of 2011 across the south and midwest included particularly destructive storms in Cincinnati (12/31/10), Vilonia (4/25/11), and Denning, AR (5/25/11) as well as the nationally publicized Joplin, MO tornado (5/22/11). Spring flooding began on the White River from rains in April and May. July saw record heat and little rain across western and northern Arkansas.
The record flooding on the White River this spring comes after another record event in 2008. Heavy rain fell towards the end of May after the area flood control reservoirs had already began to fill from April rains.

Heavy rain fell towards the end of May across northern Arkansas after reservoirs had already began to fill to capacity. Click to enlarge.
Here’s a summary of the dam releases which we saw.
Beaver Dam – Spillway gates were open from April 25-29, 2011. Lake level crested on April 26 at 1131.62 msl. Spillway gates were reopened May 2nd and closed May 4th. During this time, the lake crested at 1129.71 msl on May 3rd. Spillway gates were opened for a third time from May 20-26. The crest was at 1131.8 msl, and the maximum combined release was 52,400 cfs with gates open about 5 feet.

Beaver Dam on the evening of May 2nd as skies clear. Click to enlarge.
Table Rock Dam – Spillway gates opened April 25, 2011. Table Rock set a new high lake level of 935.5 on April 27th. Flows reached 68,000 cfs. Gates were closed by May 11th. Gates were opened again May 23rd. Combined flows were increased May 24th to about 55,000 cfs. Flows were returned to 20,000 cfs on May 28th. Spillway gates were closed on June 3rd.

Table Rock Dam during spillway releases and downstream flooding on May 25th. Click to enlarge.
Bull Shoals Dam – Six spillway gates were opened 1/2 foot on May 16th. Spillway gates were closed Friday afternoon, May 20th. Gates were opened a second time on May 23rd. Combined releases reached 58,600 cfs, the highest on record. The lake level crested on May 27th at 696.51. The Corps began lowering spillway gates May 31st, and gates were finally closed June 7th.

Bull Shoals Dam on the evening of May 25th. Click to enlarge.
Norfork Dam – Spillway releases were begun April 22 in lieu of both generators being offline for unexpected maintenance. Spillway flood control releases were increased by April 30th because of excessive rains. Releases had topped out at 38,000 cfs by May 1st and were reduced back to 6,600 cfs on May 5th. Releases were increased to 9,000 cfs on May 6th and reduced again to about 6,600 on May 11th. Releases increased on May 23rd initially to 13,250 cfs and were reduced May 24th to 6,500 cfs.

Norfork Dam spillway releases on May 25th. Click to enlarge.
One unit was repaired and brought back online June 2, and spillway flows were reduced by half. All spillway gates were closed June 9th.
No spillway releases were necessary from Greers Ferry Dam this spring.
© 2011, Scott Branyan