It is a little unusual for mid-December, but earlier this week, heavy rains in the Grand River Watershed led to the opening of floodgates at Pensacola Dam.
If you were near the dam on Monday, December 14, perhaps you noticed the main gate open, as well as seven floodgates on the east spillways.
GRDA opened those gates following a particularly rainy weekend and under direction of the United States Army Corps of Engineers (USACE), as it tries to manage excess water from not only the Grand River System but other systems in the state.
Although these gate operations occurred several months after the typically wetter months of spring, they have added to a busy year for flood control along the Grand River. It was a year that even featured the month of May’s entrance into the record books as the wettest month in Oklahoma history.
However, flood control has been a priority for GRDA since Pensacola Dam’s construction was completed in 1940. In fact, building dams for flood control purposes was part of GRDA’s original responsibility when it was created in 1935. Working closely with the USACE, the Authority continued to meet that mission in 2015, its 75th year of dam operations.
Each day, GRDA strives to be an “Oklahoma agency of excellence” by focusing on the 5 E’s: electricity, economic development, environmental stewardship, employees and efficiency. Flood control is part of this effort.
At 10AM on Tuesday, December 15:
- Grand Lake elevation was 746.36 feet. Daily target elevation for December 15 is 742 feet.
- At the direction of the United States Army Corps of Engineers, seven (7) east spillway floodgates and two (2) main gates were open at Pensacola Dam, discharging 32,046 cubic feet per second (cfs) of water.
- Six (6) units were online at the Pensacola Dam powerhouse, releasing 13,834 cfs of water through generation.
- Releases through floodgates and generation totaled 45,880 cfs.
- Inflows into Grand Lake totaled 64,345 cfs.
- Lake Hudson elevation was 624.26 feet. Normal elevation is 619 feet.
- At the direction of the United States Army Corps of Engineers, one (1) floodgate was open at Robert S. Kerr Dam, discharging 16,960 cfs of water.
- Four units were online at the Robert S. Kerr Dam powerhouse, releasing 34,290 cfs of water through generation.
- Releases through floodgates and generation totaled 51,250 cfs.
- Inflows into Lake Hudson totaled 52,105 cfs.