Oklahoma-Texas Area Office: From Drought to Flood

Written by: Kim Parish

Aerial view of Quartz Mountain Arts and Conference Center Observation Walkway.After suffering through four years of near record drought, May 2015 turned things around in a big way by being the wettest month on record for Oklahoma.

Heavy rain continued through June and July, resulting in rainfall totaling more than 40 inches in central and eastern areas of the state.

Overall, normal precipitation rates across the state were exceeded by as much as 200 percent.

Reclamation's Norman Dam, Arbuckle Dam and McGee Creek Dam all ended up in surcharge on multiple occasions, with other dams operating in the upper levels of the flood control pools.

Emergency Action Plan response levels were initiated and maintained through much of this period, including Memorial Day and Independence Day weekends, significantly impacting recreation opportunities. This event was the first time Norman Dam has operated within the surcharge pool.

On May 24th, inflows into Lake Thunderbird peaked around 60,000 cfs causing water to inundate Alameda's Twin Bridges. As designed, releases began to occur through the morning glory spillway as the reservoir crested at elevation 1053.2.

Total releases through the spillway and outlet works peaked at around 8,000 cfs. Because the downstream safe channel capacity was only 1,200 cfs, downstream flooding was inevitable. Due to the record high reservoir elevation, first filling criteria were met and additional performance monitoring at the dam was required.

The rain was no less brutal at McGee Creek. Rainfall resulted in a reservoir elevation increase of 30 feet. Releases through the outlet works were staged to full open, and although the reservoir was within inches of the earthen spillway crest, no releases were ever made through the spillway. Most recreation facilities were closed due to the high water.

Arbuckle Dam, operating at record low reservoir elevations in March, entered the surcharge pool on three separate occasions in May, June, and July. A new record high reservoir elevation was set in June, which required additional performance monitoring at the dam. Releases were made through the outlet works and the morning glory spillway.

Visitors at the state parks were evacuated in some instances. Several of the fishing docks and camping sites were heavily damaged or completely immersed in flood water.

Since flood waters have receded and lake levels are back to normal, repair has begun to restore the parks to their former beauty.

Dock repairs and campground maintenance are taking place to ensure the public has a safe place to enjoy the great outdoors. Dam inspections were performed by Reclamation at all these facilities during and after surcharge operations to ensure continued safe operation.

(Left) Lake Thunderbird Sailing Club Boat House during normal operations. (Right) Lake Thunderbird Sailing Club Boat House flooded by rising waters.

Published on June 10, 2015