DRAWDOWNS
| Table of Contents |
| Drawdown Planning Meeting |
| Rodman Reservoir Drawdown History |
| Dewatering Statistics |
1998 / 99 Drawdown Planning Meeting
| Members of the GFC, DEP, Greenways and Trails and SJRWMD met at the SJRWMD
on October 15 to discuss the proposed 1998/99 Rodman Reservoir drawdown.
The following are excerpts from a DEP memo outlining the events of that meeting.
Seventeen people attended the meeting at the SJRWMD. There was substantial discussion keyed by SJRWMD staff as to the reasoning for both the length and depth of the drawdown. Representatives of the GFC supported and recommended the drawdown as outlined in the agenda. Generally, GFC representatives stated that a 3 month drawdown was the minimum time required to accomplish the desired objectives. They also stated that drawing the reservoir down to eight feet would be the optimum, although they did not recommend that depth. They had no problem with a drawdown to 11 feet and supported Dave Bowman's recommendation. After receiving the concurrence of GFC representatives, Jeff Elledge, director of permitting for the SJRWMD stated he would process a change in our current permit to allow the drawdown to go to 11 feet instead of the current authorized 13 feet. They will attempt to schedule this for the November meeting of the SJRWMD board, for the December meeting if that is not possible*. It was suggested that we consider amending the length of the permit at this time as the current permit would expire after the next drawdown. SJRWMD understands that OGT (Office of Greenways and Trails) will proceed with the drawdown next month as planned. The current schedule anticipates reaching 13 feet on 12/24/98, by that date the issue will have been addressed by the SJRWMD board and the OGT will continue to 11 feet or hold at 13 feet. They have no objection to this procedure and stated that OGT currently is permitted for a drawdown as outlined in the current permit. There was discussion of the urgent need for some interaction with the public to advise and educate on the timing and reasoning for the drawdown. It was noted by GFC representatives that much attention had already been generated by the articles in the Save Rodman Reservoir Newsletter. They stated that they had received quite a number of calls concerning the drawdown. They had not received any opposition to procedure but questions as to the rules and regs. during the drawdown and questions as to access to the reservoir. GFC will participate in the public notification and education process which will be scheduled immediately. Past drawdowns have used the old Kenwood Road and boat ramp which appears during the drawdown. OGT staff will maintain access at the Kenwood boat ramp and through Buckman Lock. The Eureka boat ramps will not be affected and will allow access as well. The boat ramp at Rodman campground will not be usable. Dave Bowman did a superb job of designing, outlining, and presenting the drawdown proposal. It was evident during the meeting that his knowledge, experience and expertise are recognized. OGT is fortunate to continue to have him available as a resource on the Greenway. With the exception of Dave, OGT does not have the knowledge, experience, expertise, or staff to manage Rodman Reservoir and Lake Rousseau The proper agency for this task is the GFC. Finally OGT was reminded that the current permit cannot be used to effect a restoration effort, this year or any other year * The SJRWMD Board of Governors meetings are scheduled for November 10/11 and December 8/9. Two other topics were discussed: fishing regulations during the drawdown and maintenance projects. The GFC held an open house for the public at the GFC Youth Camp in the Ocala National Forest on October 30 from 3:00 to 7:00 PM. It was an informal opportunity for the public to ask question of the GFC biologists about the drawdown. Forms were available to allow citizens to submit written comments or requests concerning the drawdown. The specific temporary regulations that will be in force have not yet been decided. There are several projects the OGT has had on hold for some time. The drawdown will provide a window of accessibility to the reservoir that will allow some of these projects to be worked on more easily then when the reservoir is full: |
| 1. The "shark net" to be placed in front of the pilings to prevent manatee access to the spillway can be installed with less effort and it will be safer for the installation crew with the water level down. |
| 2. Low water provides an excellent time to easily remove snags and stumps near the navigation channel. |
| 3. It will be easier to relocate out of place buoys and replace missing ones. |
| 4. Low water facilitates water control structure maintenance. |
Downdraw History, Rodman Reservoir
Initial Flooding - 1968
| Dates | MSL Change | Comment | |
| 1 | Aug 1972 /Mar 1973 | 18' to 13' | The US Forest Service obtained a court-ordered drawdown to save wetland trees. After looking at the situation, the court ordered the reservoir returned to 18' msl stating there weren't enough trees evolved to worry about. |
| 2 | Jan 1975 / Mar 1976 | 18' to 15' | first drawdown to include a surcharge before and after to 20.5 feet |
| 3 | Aug 1979 / Nov 1979 | 18' to 14' | 6 week experimental drawdown for aquatic plant management |
| 4 | Jan 1980 / Feb 1980 | 18' to 14' | 4 week experimental drawdown for aquatic plant management |
| 5 | Sept 1980 / Mar 1981 | 18' to 13' | 24 week experimental drawdown for aquatic plant management |
| 6 | Sept 1981 / Feb 1982 | 18' to 13' | 22 week experimental drawdown for aquatic plant management |
| 7 | Dec 1985 / Mar 1986 | 18' to 13' | extensive fish kill in August 1985preceded drawdown with surcharge to 19 feet. |
| 8 | Dec 1988 / Mar 1989 | 18' to 13' | extensive fish kill in August - Sept 1989 preceded drawdown |
| 9 | Nov 1991 / Aug 1992 | 18' to 13' | included surcharge to 19' |
| October 11, 1995 | SJRWMD's Board of Governors passes a Consumptive Use Permit (CUP) for the DEP to drawdown Rodman Reservoir for a 6 month long weed kill and fisheries enhancement drawdown. This CUP was for a period of seven years and would allow three drawdowns during that period. It would expire in 2002. | ||
| 10 | Nov 1995 / Mar 1996 | 18' to 13' | included surcharge to 20' |
| December 8, 1998 | The DEP revisits the CUP situation and is granted CUP # 50242 by the SJRWMD which allows 7 drawdowns over a 20 year period. Drawdowns are to be conducted during the 6 1/2 month period between October 1 and April 15. The reservoir water level is to be restored to the 18 foot level by April 15. The reservoir is to be lowered from 18 feet to 11 feet during the drawdowns. This CUP expires in 2018. | ||
| 11 | Nov 1998 / April 1999 | 18' to 11' | included surcharge to 20' before and after the drawdown |
| 12 | Nov 2001 / April 2002 | 18' to 11' | included surcharge to 20' before and after the drawdown |
| 13 | Nov 2004 / April 2005 | 18' to 11' | included surcharge to 20' before and after the drawdown |
| 14 | Nov 2007 / April 2008 | 18' to 11' | included surcharge to 20' before and after the drawdown |
for various levels of Rodman Reservoir
| Elevation
(msl) NGVD |
Water Area
(Acres) |
Dewater Area
(Acres) |
Dewatered
(%) |
Water Volume
(Acre ft.) |
| 18 ft. | 9,200 | 0 | 0 | - |
| 17 ft. | 8,300 | 900 | 9.8 | 9,000 |
| 16 ft. | 7,500 | 1,700 | 18.5 | 8,000 |
| 15 ft. | 6,500 | 2,700 | 29.3 | 7,000 |
| 14 ft. | 5,750 | 3,450 | 37.5 | 6,000 |
| 13 ft. | 5,150 | 4,050 | 44 | 6,000 |
| 12 ft. | 4,600 | 4,600 | 50 | 4,500 |
| 11 ft. | 4,300 | 4,900 | 53.3 | - |