(7.21) WATER DATA - Management of the Apopka, Burrell, and Moss Bluff Dam Spillways
Management of the Apopka, Burrell, and Moss Bluff Dam Spillways
A 10 February 2016 Email from the St. Johns River Water Management District
An Information, Photos, & Sources Report
Compiled by Ocklawahaman Paul Nosca
With the assistance of A Cruising Down the River Captain Erika Ritter
Created: 16 February 2016
NOTE: Click-on individual photos to enlarge them!
Moss Bluff Dam Spillway
10 February 2016 Email from John Richmond of the St. Johns River Water Management District
(Excerpted text from Mr. Richmond's email follows below in ITALICS):
As you know it’s been a wet winter, an El Nino winter I guess, officially. The situation of flows in the Ocklawaha River you all are experiencing is because lakes upstream of Moss Bluff are unusually full. In the winter like this they are being kept at the upper end of what’s called their Regulation Schedule, which was set by the US Army Corps of Engineers long ago. The Regulation Schedule drops down for the summers, so the lakes have some storage for summer rains, but in the winter when there is usually very little rain the lakes are kept higher. This higher level in winter is to allow for the natural lake lowering due to evaporation, etc. Before this somewhat “normal” year of 2015, you undoubtedly know there was a drought for several years, and Moss Bluff was actually closed for 3 whole years, zero flow, from December 2011 until January 2015 !
I’ve said all that to say this, that Moss Bluff must be managed to lower Lake Griffin levels in response to rainfall. Flooding of upstream properties is of primary concern and the purpose for the creation of this Federal Flood Control Project in the Ocklawaha Basin. The St. Johns River Water Management District is the “Local Sponsor” to the Federal Government and thus is responsible to them, and for the management of the lakes it controls. The three dams in the Upper Ocklawaha chain of lakes (Apopka, which flows down to, Burrell, which flows down to Moss Bluff, which flows down to you) are all operated for flood prevention purposes. When Lakes Eustis, Harris and Dora are high then the Burrell Dam must be opened too. With Burrell open, to 900 or 1200 cfs as I needed last week, then Moss Bluff must be opened that much and more in order to help Lake Griffin drop.
I sympathize with your situations and the river / water conditions affecting fishing and tours but much of it cannot be avoided. I thank you all for these details, as we were not aware of the affects Moss Bluff discharges had on local businesses or boaters. We will be constantly aware of these facts now, and attempt to manage Moss Bluff to minimize those conditions down in your areas. I have all of you in an e-mail list now, and will provide alerts with the Moss Bluff discharge information in the future.
The following details may or may not help, but the flows you are seeing downstream are not excessive according to other discharges in the past. I’ve reviewed our historic data and taken these few examples of flows to illustrate;
Avg cfs Days From Through .
1,009 23 3-22-93 4-13-93
1,090 10 9-26-94 10-5-94
1,150 6 4-6-95 4-11-95
1,320 16 7-1-05 7-17-05
1,250 5 8-22-08 8-27-08 <- T.S. Fay
1,540 5 3-11-10 3-16-10
800 9 7-22-15 7-30-15
870 15 1-27-16 2-10-16 <- NOW
If you want to follow all our information on a computer or any Internet-ready device, you can look at these links (they update everyday at noon with the current days values);
Daily levels of Ocklawaha Lakes, a “Side View” graph showing levels, Regulation Schedules, rainfall, and discharges from the Dams;
This is a “Top Down” view of the Upper Ocklawaha lake system, showing the current discharges from all the Dams;
Finally, the entire past year of the Side View graph for Lake Griffin;
If you have additional questions or concerns, don’t hesitate to contact me again, or just call me. As a servant of the public I’m here to answer any questions you or others may have. I just wish the answers would all be what you want to hear.
John E. Richmond, P.E.
Sr. Professional Engineer
REFERENCE AS: Nosca, P. 2016. "Management of the Apopka, Burrell, and Moss Bluff Dam Spillways: A 10 February 2016 email from the St. Johns River Water Management District" webpage report. "Ocklawahaman Paul Nosca reports" website. Paul Nosca, Eureka, FL.